Journal articles on the topic 'Horizontal to vertical spectral ratios (HVSR)'
To see the other types of publications on this topic, follow the link: Horizontal to vertical spectral ratios (HVSR).
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Horizontal to vertical spectral ratios (HVSR).'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Wang, Pengfei, Paolo Zimmaro, Tristan E. Buckreis, Tatiana Gospe, Scott J. Brandenberg, Sean K. Ahdi, Alan Yong, and Jonathan P. Stewart. "Relational Database for Horizontal-to-Vertical Spectral Ratios." Seismological Research Letters 93, no. 2A (December 29, 2021): 1075–88. http://dx.doi.org/10.1785/0220210128.
Full textAbstract:
Abstract Frequency-dependent horizontal-to-vertical spectral ratios (HVSRs) of Fourier amplitudes from three-component recordings can provide useful information for site response modeling. However, such information is not incorporated into most ground-motion models, including those from Next-Generation Attenuation projects, which instead use the time-averaged shear-wave velocity (VS) in the upper 30 m of the site and sediment depth terms. To facilitate utilization of HVSR, we developed a publicly accessible relational database. This database is adapted from a similar repository for VS data and provides microtremor-based HVSR data (mHVSR) and supporting metadata, but not parameters derived from the data. Users can interact with the data directly within a web portal that contains a graphical user interface (GUI) or through external tools that perform cloud-based computations. Within the database GUI, the median horizontal-component mHVSR can be plotted against frequency, with the mean and mean ± one standard deviation (representing variability across time windows) provided. Using external interactive tools (provided as a Jupyter Notebook and an R script), users can replot mHVSR (as in the database) or create polar plots. These tools can also derive parameters of potential interest for modeling purposes, including a binary variable indicating whether an mHVSR plot contains peaks, as well as the fitted properties of those peaks (frequencies, amplitudes, and widths). Metadata are also accessible, which includes site location, details about the instruments used to make the measurements, and data processing information related to windowing, antitrigger routines, and filtering.
2
Bahavar, Manochehr, Zack J. Spica, Francisco J. Sánchez-Sesma, Chad Trabant, Arash Zandieh, and Gabriel Toro. "Horizontal-to-Vertical Spectral Ratio (HVSR) IRIS Station Toolbox." Seismological Research Letters 91, no. 6 (August 19, 2020): 3539–49. http://dx.doi.org/10.1785/0220200047.
Full textAbstract:
Abstract The horizontal-to-vertical spectral ratio (HVSR) for seismic ambient noise is a popular method that can be used to estimate the predominant frequency at a given site. In this article, we introduce the Incorporated Research Institutions for Seismology (IRIS) Data Management Center’s (DMC’s) openly available HVSR station toolbox. These tools offer a variety of ways to compute the spectral ratio by providing different averaging routines. The options range from the simple average of spectral ratios to the ratio of spectral averages. Computations take advantage of the available power spectral density estimates of ambient noise for the seismic stations, and they can be used to estimate the predominant frequency of the many three-component seismic stations available from the IRIS DMC. Furthermore, to facilitate the identification of the peaks in HVSR profiles for the assessment of the predominant frequency of station sites, the toolbox can also process the results of HVSR analysis to detect and rank HVSR peaks. To highlight the toolbox capabilities, three different examples of possible use of this toolbox for routine site-effect analysis are discussed: (1) site effects related to thawing in Arctic regions, (2) ground-motion amplification in urban area, and (3) estimation of station VS30.
3
Picozzi, M. "Statistical Analysis of Noise Horizontal-to-Vertical Spectral Ratios (HVSR)." Bulletin of the Seismological Society of America 95, no. 5 (October 1, 2005): 1779–86. http://dx.doi.org/10.1785/0120040152.
Full text
4
Mi, Binbin, Yue Hu, Jianghai Xia, and Laura Valentina Socco. "Estimation of horizontal-to-vertical spectral ratios (ellipticity) of Rayleigh waves from multistation active-seismic records." GEOPHYSICS 84, no. 6 (November 1, 2019): EN81—EN92. http://dx.doi.org/10.1190/geo2018-0651.1.
Full textAbstract:
The horizontal-to-vertical spectral-ratio (HVSR) analysis of ambient noise recordings is a popular reconnaissance tool used worldwide for seismic microzonation and earthquake site characterization. We have expanded this single-station passive HVSR technique to active multicomponent data. We focus on the calculation of the HVSR of Rayleigh waves from active-seismic records. We separate different modes of Rayleigh waves in seismic dispersion spectra and then estimate the HVSR for the fundamental mode. The mode separation is implemented in the frequency-phase velocity ([Formula: see text]-[Formula: see text]) domain through the high-resolution linear Radon transformation. The estimated Rayleigh-wave HVSR curve after mode separation is consistent with the theoretical HVSR curve, which is computed by solving the Rayleigh-wave eigenproblem in the laterally homogeneous layered medium. We find that the HVSR peak and trough frequencies are very sensitive to velocity contrast and interface depth and that HVSR curves contain information on lateral velocity variations. Using synthetic and field data, we determine the validity of estimating active Rayleigh-wave HVSR after mode separation. Our approach can be a viable and more accurate alternative to the empirical HVSR analysis method and brings a novel approach for the analysis of active multicomponent seismic data.
5
HANSAWANGKIT, Supakorn, and Teraphan ORNTHAMMARATH. "Characteristic of Northern Thailand Seismic Stations from Horizontal-to-Vertical Spectral Ratios (HVSR) Analysis." Walailak Journal of Science and Technology (WJST) 17, no. 12 (December 1, 2020): 1390–98. http://dx.doi.org/10.48048/wjst.2020.10737.
Full textAbstract:
Several major cities in Northern Thailand are located on a sedimentary basin, which could amplify ground motion from future earthquakes as they lie along several active faults. To study the seismic response and natural periods of these basins, a Horizontal to Vertical Spectral Ratio (HVSR) for each seismic station in Northern Thailand has been proposed. Several observed ground motion from moderate to small seismic events in and around Northern Thailand were used in this analysis. Several seismometers (TSA-100S, Trillium-120, PA-23, S-13 and KS 2000) of the Department of Mineral Resources (DMR) and Thai Meteorological Department (TMD) with triaxial digital accelerometer data were used. The 3 axis digital accelerometers (2-horizontal and vertical) were converted to Fourier amplitude spectral (FAS) in order to find basin natural period by Horizontal to Vertical Spectral Ratio (HVSR). This research investigates 6 stations in Northern Thailand with at least 10 observed ground motions for each station. We found that the natural period of three stations (CRAI, PAYA and PHRA) showed strong site amplification effect at low natural period (between 0.1 - 0.2 s with an amplitude larger than 2). The natural period of CMMT and MHIT stations were insignificant since CMMT and MHIT were located on the rocks. Lastly, we observed long natural period for CMCA station located in Chiang Mai basin around 2.50 s with an amplitude larger than 3. Furthermore, the computed site natural periods were compared with the average top 30 m shear wave velocity (Vs30) based on the data from the Shuttle Radar Topography Mission (SRTM) and Multichannel Analysis of Surface Wave (MASW) to find the type of soil in each area.
6
Chávez-García, Francisco J., Miguel Rodríguez, Edward H. Field, and Denis Hatzfeld. "Topographic site effects. A comparison of two nonreference methods." Bulletin of the Seismological Society of America 87, no. 6 (December 1, 1997): 1667–73. http://dx.doi.org/10.1785/bssa0870061667.
Full textAbstract:
Abstract We present an experimental study of topographic site effects. The data we use come from an experiment carried out during the summer of 1989, in Epire (northern Greece). Ten digital stations recorded a total of 68 small earthquakes. A recent article (Chávez-García et al., 1996) presented a comparison between site effects determined using horizontal-to-vertical spectral ratios (HVSR) for this data set and theoretical modeling. In this note, we compare the topographic site effects determined using HVSR with another, independent, experimental estimate: a generalized inversion scheme (GIS). Neither HVSR nor GIS depend on the availability of a reference site. We obtain a very good agreement between both estimates of topographic site effects for both horizontal components. Our results support the use of HVSR to determine topographic site effects.
7
Rong, Mianshui, Xiaojun Li, and Lei Fu. "Improvement of the objective function in the velocity structure inversion based on horizontal-to-vertical spectral ratio of earthquake ground motions." Geophysical Journal International 224, no. 1 (July 21, 2020): 1–16. http://dx.doi.org/10.1093/gji/ggaa347.
Full textAbstract:
SUMMARY Given the improvements that have been made in the forward calculations of seismic noise horizontal-to-vertical spectral ratios (NHVSRs) or earthquake ground motion HVSRs (EHVSRs), a number of HVSR inversion methods have been proposed to identify underground velocity structures. Compared with the studies on NHVSR inversion, the research on the EHVSR-based inversion methods is relatively rare. In this paper, to make full use of the widely available and constantly accumulating strong-motion observation data, we propose an S-wave HVSR inversion method based on diffuse-field approximation. Herein, the S-wave components of earthquake ground motion recordings are considered as data source. Improvements to the objective function has been achieved in this work. An objective function with the slope term is introduced. The new objective function can mitigate the multisolution phenomenon encountered when working with HVSR curves with multipeaks. Then, a synthetic case is used to show the verification of the proposed method and this method has been applied to invert underground velocity structures for six KiK-net stations based on earthquake observations. The results show that the proposed S-wave EHVSR inversion method is effective for identifying underground velocity structures.
8
Tchawe, F. N., B. Froment, M. Campillo, and L. Margerin. "On the use of the coda of seismic noise autocorrelations to compute H/V spectral ratios." Geophysical Journal International 220, no. 3 (December 6, 2019): 1956–64. http://dx.doi.org/10.1093/gji/ggz553.
Full textAbstract:
SUMMARY The horizontal to vertical spectral ratio (HVSR) of seismic ambient noise has been proven to be a fast and efficient method for characterizing the 1-D resonance frequency of the local subsurface in a practical framework. Over the last decades, theories have been developed in order to extend the exploitation of HVSR beside the frequency of its first peak, notably the diffuse field assumption (DFA) which links the HVSR to the Green’s function of the local medium assuming the diffuseness of the seismic ambient noise wavefield. However, the underlying assumption of the seismic ambient noise being a diffuse, equipartitioned field may not be satisfied under certain circumstances. In order to exploit the contribution of scattering in forging diffuse wave fields, we leverage the advantages of coda waves and present a novel procedure for computing the HVSR, using the coda part of ambient noise correlations. We applied this technique to data gathered at the plio-quaternary sedimentary basin of Argostoli, Greece. Results on this data set show the potential of the method to improve the temporal stability of the HVSR measurements compared to the classical computation, and the fit with the theoretical HVSR curve derived from the DFA theory. These results suggest that this procedure could help in extracting physical information from the HVSR and thus could lead to an extended use of these measurements to characterize the mechanical properties of the medium.
9
Neukirch, Maik, Antonio García-Jerez, Antonio Villaseñor, Francisco Luzón, Jacques Brives, and Laurent Stehly. "On the Utility of Horizontal-to-Vertical Spectral Ratios of Ambient Noise in Joint Inversion with Rayleigh Wave Dispersion Curves for the Large-N Maupasacq Experiment." Sensors 21, no. 17 (September 4, 2021): 5946. http://dx.doi.org/10.3390/s21175946.
Full textAbstract:
Horizontal-to-Vertical Spectral Ratios (HVSR) and Rayleigh group velocity dispersion curves (DC) can be used to estimate the shallow S-wave velocity (VS) structure. Knowing the VS structure is important for geophysical data interpretation either in order to better constrain data inversions for P-wave velocity (VP) structures such as travel time tomography or full waveform inversions or to directly study the VS structure for geo-engineering purposes (e.g., ground motion prediction). The joint inversion of HVSR and dispersion data for 1D VS structure allows characterising the uppermost crust and near surface, where the HVSR data (0.03 to 10s) are most sensitive while the dispersion data (1 to 30s) constrain the deeper model which would, otherwise, add complexity to the HVSR data inversion and adversely affect its convergence. During a large-scale experiment, 197 three-component short-period stations, 41 broad band instruments and 190 geophones were continuously operated for 6 months (April to October 2017) covering an area of approximately 1500km2 with a site spacing of approximately 1 to 3km. Joint inversion of HVSR and DC allowed estimating VS and, to some extent density, down to depths of around 1000m. Broadband and short period instruments performed statistically better than geophone nodes due to the latter’s gap in sensitivity between HVSR and DC. It may be possible to use HVSR data in a joint inversion with DC, increasing resolution for the shallower layers and/or alleviating the absence of short period DC data, which may be harder to obtain. By including HVSR to DC inversions, confidence improvements of two to three times for layers above 300m were achieved. Furthermore, HVSR/DC joint inversion may be useful to generate initial models for 3D tomographic inversions in large scale deployments. Lastly, the joint inversion of HVSR and DC data can be sensitive to density but this sensitivity is situational and depends strongly on the other inversion parameters, namely VS and VP. Density estimates from a HVSR/DC joint inversion should be treated with care, while some subsurface structures may be sensitive, others are clearly not. Inclusion of gravity inversion to HVSR/DC joint inversion may be possible and prove useful.
10
Zhu, Chuanbin, Fabrice Cotton, Dong-Youp Kwak, Kun Ji, Hiroshi Kawase, and Marco Pilz. "Within-site variability in earthquake site response." Geophysical Journal International 229, no. 2 (November 30, 2021): 1268–81. http://dx.doi.org/10.1093/gji/ggab481.
Full textAbstract:
SUMMARY The within-site variability in site response is the randomness in site response at a given site from different earthquakes and is treated as aleatory variability in current seismic hazard/risk analyses. In this study, we investigate the single-station variability in linear site response at K-NET and KiK-net stations in Japan using a large number of earthquake recordings. We found that the standard deviation of the horizontal-to-vertical Fourier spectral ratio at individual sites, that is single-station horizontal-to-vertical spectral ratio (HVSR) sigma σHV,s, approximates the within-site variability in site response quantified using surface-to-borehole spectral ratios (for oscillator frequencies higher than the site fundamental frequency) or empirical ground-motion models. Based on this finding, we then utilize the single-station HVSR sigma as a convenient tool to study the site-response variability at 697 KiK-net and 1169 K-NET sites. Our results show that at certain frequencies, stiff, rough and shallow sites, as well as small and local events tend to have a higher σHV,s. However, when being averaged over different sites, the single-station HVSR sigma, that is σHV, increases gradually with decreasing frequency. In the frequency range of 0.25–25 Hz, σHV is centred at 0.23–0.43 in ln scales (a linear scale factor of 1.26–1.54) with one standard deviation of less than 0.1. σHV is quite stable across different tectonic regions, and we present a constant, as well as earthquake magnitude- and distance-dependent σHV models.
11
Pinzón, Luis A., Luis G. Pujades, Albert Macau, Emilio Carreño, and Juan M. Alcalde. "Seismic Site Classification from the Horizontal-to-Vertical Response Spectral Ratios: Use of the Spanish Strong-Motion Database." Geosciences 9, no. 7 (July 4, 2019): 294. http://dx.doi.org/10.3390/geosciences9070294.
Full textAbstract:
Normally, the average of the horizontal-to-vertical (H/V) ratios of the 5% damped response spectra of ground motions is used to classify the site of strong-motion stations. In these cases, only the three-orthogonal as-recorded acceleration components are used in the analysis, and all the vector compositions that can generate a different response for each period oscillator are excluded. In this study, the Spanish strong-motion database was used to classify the sites of accelerometric stations based on the predominant periods through the average horizontal-to-vertical spectral ratios (HVSR) of recorded ground motions. Moreover, the directionality effects using the vector composition of the horizontal components of ground motions were also considered in the estimations of H/V ratios. This consideration is a relevant novelty compared to the traditional H/V ratios methods. Only earthquakes with magnitudes above 3.5 and hypocentral distances below 200 km were selected, which resulted in 692 ground-motion records, corresponding to 86 stations, from events in the period between 1993 and 2017. After the analysis, a predominant-period site classification was assigned to each station. On the whole, the obtained mean and standard deviation values of the spectral ratios are comparable to those shown by other researchers. Therefore, the advantages of the proposed procedure, which takes the directionality effects into account, can be summarized as follows: (a) The obtained information is richer and gives enables more sophisticated and realistic analyses on the basis of percentiles and (b) it is easier to detect anomalous stations, sites, and/or accelerograms. Moreover, the method eliminates the effect of directionality as a contributor to epistemic uncertainty.
12
Pinzón, Luis A., Diego A. Hidalgo-Leiva, Aarón Moya-Fernández, Victor Schmidt-Díaz, and Luis G. Pujades. "Seismic site classification of the Costa Rican Strong-Motion Network based on VS30 measurements and site fundamental period." Earth Sciences Research Journal 25, no. 4 (February 7, 2022): 383–89. http://dx.doi.org/10.15446/esrj.v25n4.93927.
Full textAbstract:
In this paper, a new seismic site classification for the Costa Rican Strong-Motion Network (CRSMN) is proposed. The soil profile classification of the Costa Rican Seismic Code based on the average shear-wave velocity of the top 30 m (VS30) is used as a reference. The site fundamental period (Tf) is included as a parameter to complement the existing characterization. For this, the VS30 measurements from 52 accelerometric stations are related to the site fundamental period obtained through horizontal-to-vertical spectral ratios (HVSR) using ground motion records from the Costa Rican Strong-Motion Database. The H/V ratios are estimated with 5% damped acceleration response spectra and with traditional Fourier amplitude spectra from the S-wave window. From the relation between VS30 and Tf, different ranges of Tf are assigned to the existing soil profile classification and a graph with three-lines and four-areas is proposed to classify the stations of the CRSMN.
13
Vidal-Villegas, J. Antonio, Carlos I. Huerta-López, Erik E. Ramírez, Rogelio Arce-Villa, and Felipe de J. Vega-Guzmán. "Experimental Approach on the Study of Ground-Motion Amplification at the Cerro Prieto Volcano, Mexicali Valley, Baja California, Mexico." Seismological Research Letters 93, no. 2A (December 22, 2021): 798–813. http://dx.doi.org/10.1785/0220200370.
Full textAbstract:
Abstract We conducted experimental work to explain the large peak ground accelerations observed at the Cerro Prieto volcano in Mexicali Valley, Mexico. Using ambient noise and earthquake data, we compared horizontal-to-vertical spectral ratios (HVSRs) computed for sites on the volcano against those calculated for locations outside it. High-HVSR values (∼11 at ∼2 Hz) were obtained on the top of the volcano at 183 m of altitude, decreasing for sites located at lower elevations. We calculated a median HVSR of ∼1 at 2 Hz from HVSRs computed for nine sites located along an N18°E transect and at an average elevation of ∼25 m. The earlier comparison suggests a relative amplification on the volcano. In addition, we calculated HVSRs from accelerograms generated by 62 earthquakes (2.6≤ML≤5.4; 4.6≤Mw≤7.2) recorded at four locations: two on the volcano (at 194 and 110 m of elevation) and two outside it. These last two sites, located up to 6 km away in a north-northwest and south-southwest direction relative to the volcano, are at an average altitude of 22 m. For the four locations, we also computed the HVSRs from ambient noise data. Although the HVSR results derived from both types of data are slightly different, we also found high HVSRs for the two sites on the volcano and low HVSRs for the two sites outside it, corroborating the relative amplification on the volcano. Using the 1D wave propagation modeling, based on the stiffness matrix method, we modeled the experimental HVSRs to analyze the local site effects. Therefore, we propose that the ground-motion amplification at the Cerro Prieto volcano may be due to a combination of its topography and shallow site effects.
14
Schleicher, Lisa S., and Thomas L. Pratt. "Characterizing Fundamental Resonance Peaks on Flat-Lying Sediments Using Multiple Spectral Ratio Methods: An Example from the Atlantic Coastal Plain, Eastern United States." Bulletin of the Seismological Society of America 111, no. 4 (July 6, 2021): 1824–48. http://dx.doi.org/10.1785/0120210017.
Full textAbstract:
ABSTRACT Damaging ground motions from the 2011 Mw 5.8 Virginia earthquake were likely increased due to site amplification from the unconsolidated sediments of the Atlantic Coastal Plain (ACP), highlighting the need to understand site response on these widespread strata along the coastal regions of the eastern United States. The horizontal-to-vertical spectral ratio (HVSR) method, using either earthquake signals or ambient noise as input, offers an appealing method for measuring site response on laterally extensive sediments, because it requires a single seismometer rather than requiring a nearby bedrock site to compute a horizontal sediment-to-bedrock spectral ratio (SBSR). Although previous studies show mixed results when comparing the two methods, the majority of these studies investigated site responses in confined sedimentary basins that can generate substantial 3D effects or have relatively small reflection coefficients at their base. In contrast, the flat-lying ACP strata and the underlying bedrock reflector should cause 1D resonance effects to dominate site response, with amplification of the fundamental resonance peaks controlled by the strong impedance contrast between the base of the sediments and the underlying bedrock. We compare site-response estimates on the ACP strata derived using the HVSR and SBSR methods from teleseismic signals recorded by regional arrays and observe a close match in the frequencies of the fundamental resonance peak (f0) determined by both methods. We find that correcting the HVSR amplitude using source term information from a bedrock site and multiplying the peak by a factor of 1.2 results in amplitude peaks that, on average, match SBSR results within a factor of 2. We therefore conclude that the HVSR method may successfully estimate regional linear weak-motion site-response amplifications from the ACP, or similar geologic environments, when appropriate region-specific corrections to the amplitude ratios are used.
15
Thomas, Amanda M., Zack Spica, Miles Bodmer, William H. Schulz, and Joshua J. Roering. "Using a Dense Seismic Array to Determine Structure and Site Effects of the Two Towers Earthflow in Northern California." Seismological Research Letters 91, no. 2A (January 8, 2020): 913–20. http://dx.doi.org/10.1785/0220190206.
Full textAbstract:
Abstract We deployed a network of 68 three-component geophones on the slow-moving Two Towers earthflow in northern California. We compute horizontal-to-vertical spectral ratios (HVSRs) from the ambient seismic field. The HVSRs have two prominent peaks, one near 1.23 Hz and another between 4 and 8 Hz at most stations. The 1.23 Hz resonance is a property of the background noise field and may be due to a velocity contrast at a few hundred meters depth. We interpret the higher frequency peaks as being related to slide deposits and invert the spectral ratios for shallow velocity structure using in situ thickness measurements as a priori constraints on the inversion. The thickness of the shallowest, low-velocity layer is systematically larger than landslide thicknesses inferred from inclinometer data acquired since 2013. Given constraints from field observations and boreholes, the inversion may reflect the thickness of deposits of an older slide that is larger in spatial extent and depth than the currently active slide. Because the HVSR peaks measured at Two Towers are caused by shallow slide deposits and represent frequencies that will experience amplification during earthquakes, the depth of the actively sliding mass may be less relevant for assessing potential slide volume and associated hazard than the thicknesses determined by our inversions. More generally, our results underscore the utility of combining both geotechnical measurements and subsurface imaging for landslide characterization and hazard assessment.
16
Triantafyllidis, Petros, Panagiotis M. Hatzidimitriou, Nikos Theodulidis, Peter Suhadolc, Costas Papazachos, Dimitris Raptakis, and Kostas Lontzetidis. "Site effects in the city of Thessaloniki (Greece) estimated from acceleration data and 1D local soil profiles." Bulletin of the Seismological Society of America 89, no. 2 (April 1, 1999): 521–37. http://dx.doi.org/10.1785/bssa0890020521.
Full textAbstract:
Abstract In this study, the site effects on seismic ground motion in the city of Thessaloniki (Greece) are estimated by applying experimental methods on acceleration data and theoretical modeling. The technique of standard spectral ratio (SSR) is applied to a reference station located on rock, while the horizontal-to-vertical spectral ratio (HVSR) technique is applied to earthquake records (entire record length including P and S waves) as well as on noise recordings. In addition, the SSR method is also applied to the vertical components. The results from all methods are compared in terms of resonant frequencies and amplification levels. The fundamental resonant frequency is identified by all methods, while the average amplification level is generally underestimated when the HVSR technique is used. An attempt is made to correlate the site amplifications computed in this study with the observed macroseismic intensities reported at the same sites for the 20 June 1978 earthquake. A relation of the form, δI=α+b⋅log[SSℛ¯(f)] is derived, where δI is the intensity increment with respect to the intensity of the reference station and SSR(ƒ) is the mean amplification factor obtained at each station using the SSR technique for a certain frequency band. In the numerical approach, we construct complete strong-motion synthetics using the modal summation method for the P-SV waves up to frequencies of 10 Hz. As input, four point sources are used, located at different distances and azimuths from the stations. Ratios of response spectra of the local 1D over the regional 1D synthetic seismograms are calculated. The obtained mean spectral amplifications are compared with those derived from experimental data, and the two sets are found to be consistent at most stations.
17
Molnar, Sheri, John Onwuemeka, and Sujan Raj Adhikari. "Rapid Post-Earthquake Microtremor Measurements for Site Amplification and Shear Wave Velocity Profiling in Kathmandu, Nepal." Earthquake Spectra 33, no. 1_suppl (December 2017): 55–72. http://dx.doi.org/10.1193/121916eqs245m.
Full textAbstract:
This paper presents application of microtremor (ambient vibration) and surface wave field techniques for post-earthquake geotechnical reconnaissance purposes in Kathmandu, Nepal. Horizontal-to-vertical spectral ratios (HVSR) are computed from microtremor recordings at 16 individual measurement locations to obtain an estimate of fundamental frequency (site period) of the subsurface soils. A combination of active- and passive-source surface wave array testing was accomplished at five key sites including Kathmandu's Durbar Square and Airport. Joint inversion of each site's higher frequency dispersion and lower frequency HVSR data sets provides an estimate of subsurface material stiffness [i.e., shear wave velocity ( V S) depth profiles]. Direct comparison of our V S profiling at Kathmandu Durbar Square and that accomplished by downhole V S and/or standard penetration testing (SPT) profiling yield similar results. Classification of the five sites based on average V S, site period, and/or basin depth is presented. There is little differentiation in these site classification designations amongst the five sites, which does not capture significant differences in observed earthquake damage.
18
Mundepi, A. K., and A. K. Mahajan. "Site response evolution and sediment mapping using horizontal to vertical spectral ratios (HVSR) of ground ambient noise in Jammu city, NW India." Journal of the Geological Society of India 75, no. 6 (June 2010): 799–806. http://dx.doi.org/10.1007/s12594-010-0070-4.
Full text
19
Yan, Peng, Zhiwei Li, Fei Li, Yuande Yang, and Weifeng Hao. "Antarctic ice-sheet structures retrieved from P-wave coda autocorrelation method and comparisons with two other single-station passive seismic methods." Journal of Glaciology 66, no. 255 (December 16, 2019): 153–65. http://dx.doi.org/10.1017/jog.2019.95.
Full textAbstract:
AbstractPassive seismology is becoming increasingly popular for glacier/ice-sheet structure investigations in Polar regions. Single-station passive seismic methods including P-wave receiver functions (PRFs), horizontal-to-vertical spectral ratio (HVSR) and a recently proposed autocorrelation method have been used to retrieve glacier/ice-sheet structures. Despite their successful applications, analysis regarding their detection abilities in different glaciological environments has not been reported. In this study, we compare ice thicknesses and vp/vs ratios obtained from the three methods using data collected at GAMSEIS and POLENET/ANET seismic arrays in Antarctica. Ice thickness estimates derived from the three methods are found to be consistent. Comparisons conducted under various model setups, including those involving tiled layers and sedimentary layers, show that the effectiveness of the autocorrelation method is not superior to the PRF method for retrieving ice-sheet structures. The autocorrelation method however can complement other methods as it only requires a single component seismic record.
20
Moisidi, M., F. Vallianatos, J. Makris, P. Soupios, and M. I. Nikolintaga. "ESTIMATION OF SEISMIC RESPONSE OF HISTORICAL AND MONUMENTAL SITES USING MICROTREMORS: A CASE STUDY IN THE ANCIENT APTERA, CHANIA, (GREECE)." Bulletin of the Geological Society of Greece 36, no. 3 (January 1, 2004): 1441. http://dx.doi.org/10.12681/bgsg.16533.
Full textAbstract:
Main purpose of the present study is to investigate the dynamic characteristics of the remainings at the ancient city of Aptera (Chania) and identify the main damage mechanism, in order to evaluate the risk of structure damage or collapse in case of future events using microtremor recordings. Our study focuses on the application of HVSR method (Horizontal to Vertical Spectral Ratio) to microtremor measurements carried out in specific sites. Registrations have been performed by means of a tridirectional sensor Lennartz 3D-Lite (1 natural Hz frequency), connected with a 24-bit digital acquisition unit. A set of 10 time series of 800 second each, sampled at 125 Hz was recorded in several sites. The selected time windows of each time series were corrected for the base line and for anomalous trends, tapered with a cosine function to the first and last 5% of the signal, and band pass filtered from 0.5 to 20 Hz with cut off frequencies at 0.3 and 22 Hz. The same procedure performed for all sites and components and finally the H/V spectral ratios were computed. Most of the sites present significant amplification peaks in frequency around 2 Hz. Finally, electrical resistivity tomography was carried out. The extracted results clearly show a very complex subsurface geometry indicated by the presence of large-scale voids, which may possibly correspond to ancient reservoirs. In the present work we confirm that the archaeological site of Aptera in Chania consists of a very complex subsurface structure and that the results obtained by HVSR method and by resistivity method are very well correlated.
21
Cho, Ikuo, and Takaki Iwata. "The relationship between normalised horizontal-to-vertical spectral ratios (HVSRs) of microtremors and the F distribution." Exploration Geophysics 49, no. 5 (October 2018): 637–46. http://dx.doi.org/10.1071/eg17110.
Full text
22
Alfaro-Diaz, Richard, and Ting Chen. "Imaging the Shallow Structure of the Yucca Flat at the Source Physics Experiment Phase II Site with Horizontal-to-Vertical Spectral Ratio Inversion and a Large-N Seismic Array." Seismological Research Letters 92, no. 5 (April 28, 2021): 2952–60. http://dx.doi.org/10.1785/0220200381.
Full textAbstract:
Abstract The Source Physics Experiment (SPE) is a series of chemical explosions at the Nevada National Security Site (NNSS) with the goal of understanding seismic-wave generation and propagation of underground explosions. To understand explosion source physics, accurate geophysical models of the SPE site are needed. Here, we utilize a large-N seismic array deployed at the SPE phase II site to generate a shallow subsurface model of shear-wave velocity. The deployment consists of 500 geophones and covers an area of, approximately, 2.5×2 km. The array is located in the Yucca Flat in the northeast corner of the NNSS, Nye County, Nevada. Using ambient-noise recordings throughout the large-N seismic array, we calculate horizontal-to-vertical spectral ratios (HVSRs) across the array. We obtain 2D seismic images of shear-wave velocities across the SPE phase II site for the shallow structure of the basin. The results clearly image two significant seismic impedance interfaces at ∼150–500 and ∼350–600 m depth. The shallower interface relates to the contrast between Quaternary alluvium and Tertiary volcanic rocks. The deeper interface relates to the contrast between Tertiary volcanic rocks and the Paleozoic bedrock. The 2D subsurface models support and extend previous understanding of the structure of the SPE phase II site. This study shows that the HVSR method in conjunction with a large-N seismic array is a quick and effective method for investigating shallow structures.
23
Murdiantoro, Randi Adzin, Sismanto Sismanto, and Marjiyono Marjiyono. "Pemetaan Daerah Rawan Kerusakan Akibat Gempabumi Di Kotamadya Denpasar dan Sekitarnya dengan Menggunakan Analisis Mikrotremor, Studi Kasus : Gempabumi Seririt 14 Juli 1976." Jurnal Fisika Indonesia 20, no. 2 (January 11, 2018): 36. http://dx.doi.org/10.22146/jfi.28373.
Full textAbstract:
Tingkat aktifitas seismik di Pulau Bali tergolong tinggi dengan 2 sumber utama gempabumi yaitu aktifitas tektonik sesar naik busur belakang (Back Arc Trust) di bagian utara dan zona subduksi lempeng Indo-Australia yang menunjam ke lempeng Eurasia di bagian selatan. Kotamadya Denpasar dan sekitarnya merupakan pusat pemerintahan Provinsi Bali dengan keberagaman infrastruktur. Penelitian ini telah dilakukan dengan tujuan memetakan daerah rawan kerusakan akibat gempabumi dengan menggunakan pengukuran mikrotremor single station yang diolah menggunakan metode HVSR (Horizontal to Vertical Spectral Ratios) dan mikrotremor array yang dianalisis menggunakan metode SPAC (Spacial Auto Correlation) untuk mendapatkan nilai vs30 (kecepatan gelombang shear sedalam 30 m). Penelitian ini menggunakan data gempabumi Seririt sebagai studi kasus untuk mencari nilai PGA batuan dasar dan PGA lapisan tanah permukaan. Hasil analisis HVSR dan PGA batuan dasar digunakan untuk mencari nilai indeks kerentanan seismik dan ground shear-strain.Hasil penelitian menunjukan Kotamadya Denpasar dan sekitarnya memiliki nilai indeks kerentanan seismik berkisar antara 0,103-33,78, nilai ground shear strain 7,00x10-6 – 2,2x10-3. Berdasarkan peta, diketahui nilai vs30 berkisar antara 171,32–764,62 m/s. Berdasarkan SNI 1726:2012 dan hasil penelitian, Klasifikasi tingkat resiko gempabumi daerah penelitian menunjukan bahwa Kecamatan Denpasar Selatan memiliki tingkat kerawanan seismik tinggi (kategori resiko I). Tingkat kerawanan seismik menengah berada di Kecamatan Denpasar Barat dan Kecamatan Kuta (kategori I, II, dan III). Daerah dengan tingkat kerawanan seismik rendah berada di Kecamatan Denpasar Timur, Kec. Denpasar Utara, Kec. Kuta Utara, Kec. Mengwi, Kec. Sukawati, Kec. Kediri (kategori I, II, III, dan IV).
24
Kurtuluş, Cengiz, Ibrahim Sertcelik, Fadime Sertçelik, Hamdullah Livaoğlu, and Cüneyt Şaş. "Investigation of Soil Characterization in Hatay Province in Turkey by Using Seismic Refraction, Multichannel Analysis of Surface Waves and Microtremor." Earth Sciences Research Journal 24, no. 4 (January 26, 2021): 473–84. http://dx.doi.org/10.15446/esrj.v24n4.79123.
Full textAbstract:
In this study, shallow seismic surveys, including seismic refraction, Multichannel Analysis of Surface Waves (MASW), Refraction Microtremor (ReMi), and Microtremor measurements were conducted to estimate site characterization at 26 strong-motion stations of AFAD (Disaster and Emergency Management Presidency) in the province of Hatay, situated in one of the most seismically active regions in southern Turkey. The Horizontal to vertical spectral ratio (HVSR) technique was applied, using smoothed Fourier spectra derived from a long duration series to determine dominant frequency values at different amplification levels. Shear wave velocity up to 30 m of the ground was detected with MASW analysis. In the ReMi analysis, up to 80 m was reached with a corresponding average of 650 m/s shear wave velocity. The shear wave velocities estimated by the MASW method up to 30 m were compared with those found by the ReMi method, and they were observed to be very compatible. The province of Hatay was classified according to Vs30 based NEHRP Provisions, Eurocode-8, the Turkish Building Earthquake Regulation (TBDY-2018), and Rodriguez-Marek et al. (2001). The shear-wave velocity (Vs30), Horizontal to Vertical ratio’s (H/V) peak amplitude, dominant period, and site class of each site were determined. The H/V peak amplitudes range between 1.9 and 7.6, while the predominant periods vary from 0.23 sec to 2.94sec in the study area. These results are investigated to explain the consistency of site classification schemes.
25
Paolucci, Roberto. "Numerical evaluation of the effect of cross-coupling of different components of ground motion in site response analyses." Bulletin of the Seismological Society of America 89, no. 4 (August 1, 1999): 877–87. http://dx.doi.org/10.1785/bssa0890040877.
Full textAbstract:
Abstract The effect of cross-coupling between the three components of ground motion in the evaluation of site-response functions, such as standard spectral ratios (SSRs) and horizontal-to-vertical spectral ratios (HVSRs), is analyzed in this article. Numerical analyses of the seismic response of fully 3D geological structures, namely, a real topographic irregularity and an ideal stratigraphic inclusion, have been carried out to obtain a 3D transfer function in the form of a 3 × 3 matrix. Each element of this matrix contains the frequency response in the ith direction due to an input motion in the jth direction. A synthetic set of acceleration time histories at the surface of the geological irregularity has been created by convolution with the 3D transfer function, using as input motion different real multicomponent strong-motion accelerograms recorded at stiff-soil or rock sites. The SSRs and HVSRs are calculated and compared with the theoretical 3D transfer function in order to highlight the effect of cross-coupling terms. These are found to generate a rather large dispersion in the site-response functions, as well as response peaks that could be misleading in the interpretation of both numerical and observed spectral ratios.
26
Del Gaudio, V., S. Coccia, J. Wasowski, M. R. Gallipoli, and M. Mucciarelli. "Detection of directivity in seismic site response from microtremor spectral analysis." Natural Hazards and Earth System Sciences 8, no. 4 (July 25, 2008): 751–62. http://dx.doi.org/10.5194/nhess-8-751-2008.
Full textAbstract:
Abstract. Recent observations have shown that slope response to seismic shaking can be characterised by directional variations of a factor of 2–3 or larger, with maxima oriented along local topography features (e.g. maximum slope direction). This phenomenon appears influenced by slope material properties and has occasionally been detected on landslide-prone slopes, where a down-slope directed amplification could enhance susceptibility to seismically-induced landsliding. The exact conditions for the occurrence of directional amplification remain still unclear and the implementation of investigation techniques capable to reveal the presence of such phenomena is desirable. To this purpose we tested the applicability of a method commonly used to evaluate site resonance properties (Horizontal to Vertical Noise Ratio – HVNR or Nakamura's method) as reconnaissance technique for the identification of site response directivity. Measurements of the azimuthal variation of H/V spectral ratios (i.e. between horizontal and vertical component) of ambient microtremors were conducted in a landslide-prone study area of central Italy where a local accelerometric network had previously provided evidence of directivity phenomena on some slopes. The test results were compared with average H/V spectral ratios obtained for low-to-moderate earthquakes recorded by the accelerometric stations. In general, noise and seismic recordings provided different amplitudes of spectral ratios at similar frequencies, likely because of differences in signal and instrument characteristics. Nevertheless, both kinds of recordings showed that at sites affected by site response directivity major H/V peaks have orientations consistent (within 20°–30°) with the direction of maximum shaking energy. Therefore, HVNR appears to be a promising technique for identifying seismic response directivity. Furthermore, in a comparative test conducted on a slope mantled in part by a deep-seated landslide we detected spectral peaks with orientations close to the maximum slope direction, whereas no evidence of directivity was found outside the slide boundaries. This indicates the influence of the landslide body on seismic response directivity.
27
Bottelin, Pierre, Laurent Baillet, Aurore Carrier, Eric Larose, Denis Jongmans, Ombeline Brenguier, and Héloïse Cadet. "Toward Workable and Cost-Efficient Monitoring of Unstable Rock Compartments with Ambient Noise." Geosciences 11, no. 6 (June 4, 2021): 242. http://dx.doi.org/10.3390/geosciences11060242.
Full textAbstract:
Ambient Vibration-Based Structural Health Monitoring (AVB–SHM) studies on prone-to-fall rock compartments have recently succeeded in detecting both pre-failure damaging processes and reinforcement provided by bolting. The current AVB–SHM instrumentation layout is yet generally an overkill, creating cost and power issues and sometimes requiring advanced signal processing techniques. In this article, we paved the way toward an innovative edge-computing approach tested on ambient vibration records made during the bolting of a ~760 m3 limestone rock column (Vercors, France). First, we established some guidelines for prone-to-fall rock column AVB–SHM by comparing several basic, computing-efficient, seismic parameters (i.e., Fast Fourier Transform, Horizontal to Vertical and Horizontal to Horizontal Spectral Ratios). All three parameters performed well in revealing the unstable compartment’s fundamental resonance frequency. HHSR appeared as the most consistent spectral estimator, succeeding in revealing both the fundamental and higher modes. Only the fundamental mode should be trustfully monitored with HVSR since higher peaks may be artifacts. Then, the first application of a novelty detection algorithm on an unstable rock column AVB–SHM case study showed the following: the feasibility of automatic removing the adverse thermomechanical fluctuations in column’s dynamic parameters based on machine learning, as well as the systematic detection of clear, permanent change in column’s dynamic behavior after grout injection and hardening around the bolts (i1 and i2). This implementation represents a significant workload reduction, compared to physical-based algorithms or numerical twin modeling, and shows better robustness with regard to instrumentation gaps. We believe that edge-computing monitoring systems combining basic seismic signal processing techniques and automatic detection algorithms could help facilitate AVB–SHM of remote natural structures such as prone-to-fall rock compartments.
28
Delgado, José, Juan José Galiana-Merino, Francisco J. García-Tortosa, Jesús Garrido, Luca Lenti, Salvatore Martino, José A. Peláez, Martín J. Rodríguez-Peces, Carlos Sanz de Galdeano, and Juan L. Soler-Llorens. "Ambient Noise Measurements to Constrain the Geological Structure of the Güevéjar Landslide (S Spain)." Applied Sciences 11, no. 4 (February 5, 2021): 1454. http://dx.doi.org/10.3390/app11041454.
Full textAbstract:
The reactivation of very large landslides may cause severe damage to society. Its prevention and management requires detailed information on the geometry and structure of these landslides, but the use of standard techniques (boreholes) may be prohibitive from an economic point of view. To overcome these difficulties, geophysical techniques are of special interest because they allow for studying very large areas at a reasonable cost. In this paper, we present a case study wherein the analysis of ambient noise allowed us to produce a model of a large landslide near Granada (southern Spain). The geometry and location of the failure zone, as well as the assessment of the state of involved materials, were estimated by combining two available boreholes and different geophysical techniques (downhole tests and the spectral analysis of ambient noise, horizontal to vertical spectral ratios (HVSR) and the frequency-wavenumber (f-k) methods). The results have allowed us to differentiate between values within the landslide mass with respect to those of stable materials, and to perform for the first time a comprehensive geological model of this unstable mass. Differences were also observed within the landslide mass (earth flow vs. slide zones), which are attributed to differences in the degree of alteration and the disturbance of the internal structure of materials constituting the landslide mass. These results show that techniques based on the measurement of ambient noise are of special interest for studying very large, highly remolded landslide masses.
29
Huang, Yihe. "Smooth Crustal Velocity Models Cause a Depletion of High-Frequency Ground Motions on Soil in 2D Dynamic Rupture Simulations." Bulletin of the Seismological Society of America 111, no. 4 (June 15, 2021): 2057–70. http://dx.doi.org/10.1785/0120200311.
Full textAbstract:
ABSTRACT A depletion of high-frequency ground motions on soil sites has been observed in recent large earthquakes and is often attributed to a nonlinear soil response. Here, I show that the reduced amplitudes of high-frequency horizontal-to-vertical spectral ratios (HVSRs) on soil can also be caused by a smooth crustal velocity model with low shear-wave velocities underneath soil sites. I calculate near-fault ground motions using both 2D dynamic rupture simulations and point-source models for both rock and soil sites. The 1D velocity models used in the simulations are derived from empirical relationships between seismic wave velocities and depths in northern California. The simulations for soil sites feature lower shear-wave velocities and thus larger Poisson’s ratios at shallow depths than those for rock sites. The lower shear-wave velocities cause slower shallow rupture and smaller shallow slip, but both soil and rock simulations have similar rupture speeds and slip for the rest of the fault. However, the simulated near-fault ground motions on soil and rock sites have distinct features. Compared to ground motions on rock, horizontal ground acceleration on soil is only amplified at low frequencies, whereas vertical ground acceleration is deamplified for the whole frequency range. Thus, the HVSRs on soil exhibit a depletion of high-frequency energy. The comparison between smooth and layered velocity models demonstrates that the smoothness of the velocity model plays a critical role in the contrasting behaviors of HVSRs on soil and rock for different rupture styles and velocity profiles. The results reveal the significant role of shallow crustal velocity structure in the generation of high-frequency ground motions on soil sites.
30
Pacheco, D., E. D. Mercerat, F. Courboulex, L. F. Bonilla, A. Laurendeau, and A. Alvarado. "Profiling the Quito basin (Ecuador) using seismic ambient noise." Geophysical Journal International 228, no. 2 (October 11, 2021): 1419–37. http://dx.doi.org/10.1093/gji/ggab408.
Full textAbstract:
SUMMARY Quito, the capital of Ecuador, with more than 2.5 M inhabitants, is exposed to a high seismic hazard due to its proximity to the Pacific subduction zone and active crustal faults, both capable of generating significant earthquakes. Furthermore, the city is located in an intermontane piggy-back basin prone to seismic wave amplification. To understand the basin’s seismic response and characterize its geological structure, 20 broad and medium frequency band seismic stations were deployed in Quito’s urban area between May 2016 and July 2018 that continuously recorded ambient seismic noise. We first compute horizontal-to-vertical spectral ratios to determine the resonant frequency distribution in the entire basin. Secondly, we cross-correlate seismic stations operating simultaneously to retrieve interstations surface-wave Green’s functions in the frequency range of 0.1–2 Hz. We find that Love waves travelling in the basin’s longitudinal direction (NNE–SSW) show much clearer correlograms than those from Rayleigh waves. We then compute Love wave phase-velocity dispersion curves and invert them in conjunction with the HVSR curves to obtain shear-wave velocity profiles throughout the city. The inversions highlight a clear difference in the basin’s structure between its northern and southern parts. In the centre and northern areas, the estimated basin depth and mean shear-wave velocity are about 200 m and 1800 ms−1, respectively, showing resonance frequency values between 0.6 and 0.7 Hz. On the contrary, the basement’s depth and shear-wave velocity in the southern part are about 900 m and 2500 ms−1, having a low resonance frequency value of around 0.3 Hz. This difference in structure between the centre-north and the south of the basin explains the spatial distribution of low-frequency seismic amplifications observed during the Mw 7.8 Pedernales earthquake in April 2016 in Quito.
31
Pischiutta, Marta, Aybige Akinci, Elisa Tinti, and André Herrero. "Broad-band ground-motion simulation of 2016 Amatrice earthquake, Central Italy." Geophysical Journal International 224, no. 3 (August 31, 2020): 1753–79. http://dx.doi.org/10.1093/gji/ggaa412.
Full textAbstract:
SUMMARY On 24 August 2016 at 01:36 UTC a ML6.0 earthquake struck several villages in central Italy, among which Accumoli, Amatrice and Arquata del Tronto. The earthquake was recorded by about 350 seismic stations, causing 299 fatalities and damage with macroseismic intensities up to 11. The maximum acceleration was observed at Amatrice station (AMT) reaching 916 cm s–2 on E–W component, with epicentral distance of 15 km and Joyner and Boore distance to the fault surface (RJB) of less than a kilometre. Motivated by the high levels of observed ground motion and damage, we generate broad-band seismograms for engineering purposes by adopting a hybrid method. To infer the low frequency seismograms, we considered the kinematic slip model by Tinti et al . The high frequency seismograms were produced using a stochastic finite-fault model approach based on dynamic corner-frequency. Broad-band synthetic time-series were therefore obtained by merging the low and high frequency seismograms. Simulated hybrid ground motions were compared both with the observed ground motions and the ground-motion prediction equations (GMPEs), to explore their performance and to retrieve the region-specific parameters endorsed for the simulations. In the near-fault area we observed that hybrid simulations have a higher capability to detect near source effects and to reproduce the source complexity than the use of GMPEs. Indeed, the general good consistency found between synthetic and observed ground motion (both in the time and frequency domain), suggests that the use of regional-specific source scaling and attenuation parameters together with the source complexity in hybrid simulations improves ground motion estimations. To include the site effect in stochastic simulations at selected stations, we tested the use of amplification curves derived from HVRSs (horizontal-to-vertical response spectra) and from HVSRs (horizontal-to-vertical spectral ratios) rather than the use of generic curves according to NTC18 Italian seismic design code. We generally found a further reduction of residuals between observed and simulated both in terms of time histories and spectra.
32
Neukirch, Maik, Antonio García-Jerez, Antonio Villaseñor, Francisco Luzón, Mario Ruiz, and Luis Molina. "Horizontal-to-Vertical Spectral Ratio of Ambient Vibration Obtained with Hilbert–Huang Transform." Sensors 21, no. 9 (May 10, 2021): 3292. http://dx.doi.org/10.3390/s21093292.
Full textAbstract:
The Horizontal-to-Vertical Spectral Ratio (HVSR) of ambient vibration measurements is a common tool to explore near surface shear wave velocity (Vs) structure. HVSR is often applied for earthquake risk assessments and civil engineering projects. Ambient vibration signal originates from the combination of a multitude of natural and man-made sources. Ambient vibration sources can be any ground motion inducing phenomena, e.g., ocean waves, wind, industrial activity or road traffic, where each source does not need to be strictly stationary even during short times. Typically, the Fast Fourier Transform (FFT) is applied to obtain spectral information from the measured time series in order to estimate the HVSR, even though possible non-stationarity may bias the spectra and HVSR estimates. This problem can be alleviated by employing the Hilbert–Huang Transform (HHT) instead of FFT. Comparing 1D inversion results for FFT and HHT-based HVSR estimates from data measured at a well studied, urban, permanent station, we find that HHT-based inversion models may yield a lower data misfit χ2 by up to a factor of 25, a more appropriate Vs model according to available well-log lithology, and higher confidence in the achieved model.
33
Pentaris, F. P. "A novel horizontal to vertical spectral ratio approach in a wired structural health monitoring system." Journal of Sensors and Sensor Systems 3, no. 2 (August 8, 2014): 145–65. http://dx.doi.org/10.5194/jsss-3-145-2014.
Full textAbstract:
Abstract. This work studies the effect ambient seismic noise can have on building constructions, in comparison with the traditional study of strong seismic motion in buildings, for the purpose of structural health monitoring. Traditionally, engineers have observed the effect of earthquakes on buildings by usage of seismometers at various levels. A new approach is proposed in which acceleration recordings of ambient seismic noise are used and horizontal to vertical spectra ratio (HVSR) process is applied, in order to determine the resonance frequency of movement due to excitation of the building from a strong seismic event. The HVSR technique is widely used by geophysicists to study the resonance frequency of sediments over bedrock, while its usage inside buildings is limited. This study applies the recordings inside two university buildings attached to each other, but with different construction materials and different years of construction. Also there is HVSR application in another much older building, with visible cracks in its structure. Sensors have been installed on every floor of the two university buildings, and recordings have been acquired both of ambient seismic noise and earthquakes. Resonance frequencies for every floor of every building are calculated, from both noise and earthquake records, using the HVSR technique for the ambient noise data and the receiver function (RF) for the earthquake data. Differential acceleration drift for every building is also calculated, and there is correlation with the vulnerability of the buildings. Results indicate that HVSR process on acceleration data proves to be an easy, fast, economical method for estimation of fundamental frequency of structures as well as an assessment method for building vulnerability estimation. Comparison between HVSR and RF technique shows an agreement at the change of resonance frequency as we move to higher floors.
34
Iswanto, Eko Rudi, Yuni Indrawati, and Theo Alvin Riyanto. "Studi Mikrotremor dengan Metode Horizontal to Vertical Spectral Ratio (HVSR) di Tapak RDE, Serpong." EKSPLORIUM 40, no. 2 (November 30, 2019): 105. http://dx.doi.org/10.17146/eksplorium.2019.40.2.5489.
Full textAbstract:
ABSTRAKBencana alam seperti kejadian gempa bumi dapat menyebabkan kerusakan pada area tapak dan infrastruktur termasuk fasilitas reaktor nuklir. Fenomena ini perlu dipahami secara komprehensif melalui catatan sejarah karakteristik dinamik tapak. Penggunaan mikrotremor dengan metode Horizontal to Vertical Spectral Ratio (HVSR) telah digunakan secara luas dalam investigasi bawah permukaan sejak satu dekade terakhir. Tujuan penelitian ini adalah mengetahui karakteristik geologi setempat dan karakteristik dinamis bawah permukaan. Penelitian ini mengaplikasikan penggunaan mikrotremor metode HVSR di tapak Reaktor Daya Eksperimental (RDE) di Serpong. Pengukuran dilakukan di 15 lokasi, kemudian data diolah dengan metode HVSR menggunakan perangkat lunak Geopsy. Hasil analisis menunjukkan bahwa Tapak RDE mempunyai nilai frekuensi dominan antara 3,06 Hz–23,27 Hz dan faktor amplifikasi 1,84–6,37. Bagian timur laut dan tenggara tapak memiliki indeks kerentanan seismik yang lebih tinggi dibandingkan dengan bagian lainnya. Oleh karena itu, pilihan lokasi gedung reaktor di area barat daya sudah tepat kerena memiliki faktor amplifikasi, ketebalan sedimen, dan indeks kerentanan seismik yang relatif rendah.ABSTRACTNatural disaster like earthquake can cause damage to the site and the infrastructure including nuclear reactor facilities. This phenomenon needs comprehensively understood through its dynamic characteristics historical records of the site. The use of Horizontal to Vertical Spectral Ratio (HVSR) method has been widely used for subsurface investigation since last decade. The aimed of the research is to obtain local geological and subsurface dynamic characetristics. This research is applying the use of HVSR method for Experimental Power Reactor (RDE) in Serpong. The measurements are in 15 locations, and then the data is processed by using Geopsy software. The analysis result shows that the RDE site has dominant frequncy values between 3.06 Hz–23.271 Hz and amplification factor 1.84–6.37. The northeast and southeast areas of the site have higher seismic vulnerability index than in other area. Therefore, the selection for reactor bulding location in the southwest area is proper because it has lower amplification factor, sedimen thickness, and seismic vulnerability index.
35
Praja, Nia Kurnia, Sitti Lasmi Mangininsih, Nia Kurnia Praja, Hasria, and Azhar. "Pemetaan Lapisan Tanah Menggunakan Data Mikrotremor HVSR dan Dampaknya Terhadap Daya Dukung Tanah di Kawasan Kota Kendari." Jurnal Geologi dan Sumberdaya Mineral 24, no. 1 (February 7, 2023): 51–58. http://dx.doi.org/10.33332/jgsm.geologi.v24i1.724.
Full textAbstract:
Kota Kendari memiliki risiko tinggi terhadap bahaya guncangan gempa bumi karena dekat dengan sumber gempa bumi. Kondisi geologi yang heterogen menyebabkan respon berbeda terhadap efek ground motion, tergantung pada karakteristik penyusun litologi pada formasi tersebut. Untuk mengetahui karakteristik lapisan tanah, data mikrotremor HVSR (Horizontal to Vertical Spectral Ratio) digunakan dan diolah dengan software Geopsy. Horizontal to Vertical Spectral Ratioadalah satu metode yang sangat mudah untuk memperkirakan frekwensi alami dari lapisan tanah yang dikonversi dalam bentuk kecepatan gelombang geser (Vs). Nilai kecepatan gelombang geser merupakan salah satu parameter untuk mengetahui kondisi tanah serta memperkirakan bahaya ground motion secara spesifik. Kajian ini berkaitan dengan upaya mitigasi terhadap guncangan gempa bumi dengan cara memetakan daerah yang memiliki potensi kerusakan yang cukup besar terhadap gempa bumi. . Kata kunci: HVSR Mikrotremor, kecepatan gelombang geser (Vs), software Geopsy, Lapisan Tanah
36
Mendecki, Maciej J., Barbara Bieta, Mateusz Mateuszów, and Paweł Suszka. "Comparison of site effect values obtained by HVSR and HVSRN methods for single-station measurements in Tarnówek, South-Western Poland." Contemporary Trends in Geoscience 5, no. 1 (June 1, 2016): 18–27. http://dx.doi.org/10.1515/ctg-2016-0002.
Full textAbstract:
Abstract This study compares the HVSR technique (Horizontal to Vertical Spectral Ratio), based on seismic event records, and the HVSRN technique (Horizontal to Vertical Spectral Ratio of Noise) using seismic noise registrations. Both methods allow us to study the amplification phenomenon of a horizontal component of seismic waves when the waves reach loose sediments in subsurface layers. The seismic data were measured at a three-component single seismic station located in the village of Tarnówek, in the Legnica-Głogów Copper District. The results of the study demonstrate that average HVSRN and HVSR maxima can be distinguished: for periods approximately 3.78 s (H/V = 6.2) and 3.969 s (H/V = 8.98) respectively. The evaluated share of the Rayleigh wave component in the recorded values was β = 0.58 and it can be suggested that the Love wave share in surface motion was insignificant. The Love wave share remains unknown.
37
Yuliawati, Winda Styani, Syamsurijal Rasimeng, and Karyanto Karyanto. "PENGOLAHAN DATA MIKROTREMOR BERDASARKAN METODE HVSR DENGAN MENGGUNAKAN MATLAB." Jurnal Geofisika Eksplorasi 5, no. 1 (January 17, 2020): 45–59. http://dx.doi.org/10.23960/jge.v5i1.22.
Full textAbstract:
The research has conducted to get the result of Matlab program for microtremor data processing. The purpose of this research is to apply Matlab software into microtremor data processing. The microtremor is the ground motion to identify earthquake vulnerability by using HVSR (Horizontal to Vertical Spectral Ratio) method. The HVSR method for comparing both of horizontal component and vertical component on microtremor wave to obtain the result dominant frequency(f0) based on the high spectrum H/V value from the analysis of HVSR curve. Based on this research which concludes that microtremor data processing has processed using Matlab software. The result of this data processing gives similar value from the geopsy software. The value of dominant frequency by Matlab software and geopsy software calculation are classified on the site class type II which is dominantly alluvium. Whereas, the result of dominant period by geopsy and Matlab are classified on the site class type I which shows as the bedrock.
38
Gallipoli, Maria Rosaria, Marco Mucciarelli, Salvatore Gallicchio, Marcello Tropeano, and Carmine Lizza. "Horizontal to Vertical Spectral Ratio (HVSR) Measurements in the Area Damaged by the 2002 Molise, Italy, Earthquake." Earthquake Spectra 20, no. 1_suppl (July 2004): 81–93. http://dx.doi.org/10.1193/1.1766306.
Full textAbstract:
Following the 2002 Molise, Italy, earthquake, we performed a set of horizontal to vertical spectral ratio (HVSR) measurements in the damaged area. We recorded microtremors in all the municipalities reaching VI on the Mercalli-Cancani-Sieberg intensity scale. To calibrate our measurements, we installed accelerometers in two of the most damaged areas. We wanted to study HVSR in an area that is geologically different from areas commonly affected by earthquakes in the Southern Apennines. We also wanted to avoid the damage-attraction effect: after a strong event, most researchers study site amplification just where most of the damage has occurred. They might not consider that different structure vulnerability may mask the true distribution of site amplification. We checked for a possible correlation between observed intensity and the average of the non-flat HVSR measured in each municipality. The significant correlation indicates that site amplification has played a role in the damage pattern observed.
39
Cheng, Tianjian, Brady R. Cox, Joseph P. Vantassel, and Lance Manuel. "A statistical approach to account for azimuthal variability in single-station HVSR measurements." Geophysical Journal International 223, no. 2 (July 17, 2020): 1040–53. http://dx.doi.org/10.1093/gji/ggaa342.
Full textAbstract:
SUMMARY The horizontal-to-vertical spectral ratio (HVSR) of ambient noise is commonly used to infer a site's resonance frequency (${f_{0,site}}$). HVSR calculations are performed most commonly using the Fourier amplitude spectrum obtained from a single merged horizontal component (e.g. the geometric mean component) from a three-component sensor. However, the use of a single merged horizontal component implicitly relies on the assumptions of azimuthally isotropic seismic noise and 1-D surface and subsurface conditions. These assumptions may not be justified at many sites, leading to azimuthal variability in HVSR measurements that cannot be accounted for using a single merged component. This paper proposes a new statistical method to account for azimuthal variability in the peak frequency of HVSR curves (${f_{0,HVSR}}$). The method uses rotated horizontal components at evenly distributed azimuthal intervals to investigate and quantify azimuthal variability. To ensure unbiased statistics for ${f_{0,HVSR}}$ are obtained, a frequency-domain window-rejection algorithm is applied at each azimuth to automatically remove contaminated time windows in which the ${f_{0,HVSR}}$ values are statistical outliers relative to those obtained from the majority of windows at that azimuth. Then, a weighting scheme is used to account for different numbers of accepted time windows at each azimuth. The new method is applied to a data set of 114 HVSR measurements with significant azimuthal variability in ${f_{0,HVSR}}$, and is shown to reliably account for this variability. The methodology is also extended to the estimation of a complete lognormal-median HVSR curve that accounts for azimuthal variability. To encourage the adoption of this statistical approach to accounting for azimuthal variability in single-station HVSR measurements, the methods presented in this paper have been incorporated into hvsrpy, an open-source Python package for HVSR processing.
40
Chandler, Val W., and Richard S. Lively. "Utility of the horizontal-to-vertical spectral ratio passive seismic method for estimating thickness of Quaternary sediments in Minnesota and adjacent parts of Wisconsin." Interpretation 4, no. 3 (August 1, 2016): SH71—SH90. http://dx.doi.org/10.1190/int-2015-0212.1.
Full textAbstract:
Quaternary glacial and fluvial sediments in Minnesota and adjacent areas are a major source for groundwater, and they are important to many geologic investigations. Unfortunately, the thicknesses of these widespread sediments are often poorly known. The horizontal-to-vertical-spectral ratio (HVSR) passive seismic method is being increasingly used in the region to assist in mapping the thickness of these sediments and the topography of the underlying bedrock surface. HVSR results when control sites with known sediment thickness are used to derive calibration curves that in turn are used to estimate sediment thicknesses in areas lacking control. The HVSR method must be used with appropriate caution. Extreme variations in S-wave velocities of near-surface materials can complicate or even negate the use of calibration curves, and very irregular bedrock surfaces can produce weak, multipeak HVSR spectra that are difficult to interpret. Over soft bedrock, HVSR peaks may reflect intrabedrock features, and velocity contrasts within the glacial sequence can overwhelm HVSR bedrock signatures. Nonetheless, the HVSR method has proven a useful tool to investigate Quaternary geology and depth to bedrock in areas of the state where subsurface data are limited. Thickness estimate errors are usually less than 25%, which is adequate for many geologic applications. The addition of multilocation spectral profiles and cross sections anchored with bedrock control points has allowed us to use data with poor signal quality and to achieve good continuity away from control stations. HVSR methods provide a suitable and cheaper alternative to conventional seismic studies, and they help to target sites for Quaternary drilling programs, bedrock topography evaluation, and determining glacial sediment thickness for 3D mapping. In areas where conventional seismic profiling may be necessary, the HVSR method is useful in selecting and prioritizing targets. The HVSR method should have widespread application in the glaciated areas of the north-central midcontinent.
41
Perdhana, Radhitya, and Budi Eka Nurcahya. "Seismic microzonation based on microseismic data and damage distribution of 2006 Yogyakarta Earthquake." E3S Web of Conferences 76 (2019): 03008. http://dx.doi.org/10.1051/e3sconf/20197603008.
Full textAbstract:
The 2006 Yogyakarta earthquake caused an extensive damage to various areas of Yogyakarta regions. The damage distribution indicates the role of local site effects during the earthquake as the damage extended from Bantul Regency in Yogyakarta Province to Klaten Regency in Central Java. Microzonation based on the damage distribution is then carried out using Horizontal-to-Vertical Spectral Ratio (HVSR) technique. From this technique, amplification factor and predominant frequency can be obtained and then spatially mapped. Inversion can also be conducted to the HVSR curves to infer the geological condition of the study area.
42
Qingling, Du, Liu Zhengping, and Liu Shijie. "Analysis of Influencing Factors and Numerical Simulation of Horizontal-to-Vertical Spectral Ratio Method." Journal of Earthquake and Tsunami 14, no. 01 (September 18, 2019): 2050004. http://dx.doi.org/10.1142/s1793431120500049.
Full textAbstract:
To improve the calculation accuracy of the horizontal-to-vertical spectral ratio (HVSR) method, this study theoretically analyzed the influencing factors of Rayleigh wave polarizability. The phase difference of the horizontal component and the phase difference of the vertical component are found to play a key role in calculating the polarizability. The influence mechanism of the superposition of body waves and different Rayleigh waves on the polarizability of the Rayleigh wave is derived. The effects of the body wave, amplitude, frequency and Rayleigh wave superposition of different sources on the polarizability are verified by numerical simulation. The results show that the body wave significantly interferes with the polarizability of the Rayleigh wave. When a signal contains more than one set of Rayleigh waves, the superposition of the same-source Rayleigh waves does not affect the ratio. However, the superposition of Rayleigh waves from different sources significantly interferes with the calculation of the polarizability. This provides a technical method and a theoretical basis for accurately extracting the Rayleigh wave polarizability dispersion curve from a seismic record signal. This would help improve the detection accuracy of the HVSR method for ground pulse signals.
43
Griffiths, Shawn, and Abbas Ansariaval. "Performing horizontal to vertical ratio testing in stiff soils in and around Grand Teton National Park." UW National Parks Service Research Station Annual Reports 42 (December 15, 2019): 5–10. http://dx.doi.org/10.13001/uwnpsrc.2019.5733.
Full textAbstract:
Horizontal to vertical spectral ratio (HVSR) testing was completed at two cross sections in and around GTNP. The HVSR testing produced reliable estimates of the fundamental frequencies for many of the sites tested. The goal of the testing was to determine a depth of soil above competent bedrock. However the fundamental frequencies recorded yielded predicted depths that are much shallower than expected. Also the predicted depths did not increase at greater distance from the Teton Range, which would be expected at these sites. Based on these predictions the authors do not believe the frequencies recorded are a good indication of the depth of the soil above bedrock but instead it is believed that the depths correspond with a layer of softer topsoil/overburden above a stiffer gravel layer. Although the goal of measuring the depth of soil above bedrock was not met, HVSR produced results that may be useful to others for determination of a fundamental frequency of resonance at our testing locations.
Featured photo by Anna Cressman, taken from the AMK Ranch photo collection. https://flic.kr/p/2jjWZGT
44
La Rocca, M., G. D. Chiappetta, A. Gervasi, and R. L. Festa. "Non-stability of the noise HVSR at sites near or on topographic heights." Geophysical Journal International 222, no. 3 (June 17, 2020): 2162–71. http://dx.doi.org/10.1093/gji/ggaa297.
Full textAbstract:
SUMMARY The horizontal to vertical spectral ratio (HVSR) of seismic noise is often used to investigate site effects, and it is usually assumed to be a stable feature of the site considered. Here we show that such an assumption is not always justified, and may lead to incorrect conclusions. The HVSR analysis was performed on ambient seismic noise recordings lasting from weeks to months at many sites in Calabria, Italy. Results show a variety of site effects, from the resonance of a shallow sedimentary layer to the polarized amplification of horizontal ground motion associated with topographic effects. We describe the results of seven sites whose HVSR is characterized by dual content: one that is persistent, and another appearing only occasionally. Two sites very near the coast of the Tyrrhenian sea and five sites in the Calabrian Arc mountains show the most remarkable results. The shape of the HVSR changes significantly at these sites when the amplitude of background noise increases in a broad frequency band during periods of bad weather. The occasional contribution to the HVSR consists of one or more peaks, depending on the site, that appear only when the amplitude of ambient noise is higher than usual. The seven sites where we observe the HVSR variability are all located in complex geological environments, on mountains, ridges or foothills. A variation of the HVSR correlated with the day–night cycle is also observed at some of these sites.
45
Sisianti, Anci, La Hamimu, and Abdul Manan. "ANALISIS SPEKTRUM HVSR MIKROTREMOR UNTUK ESTIMASI KEDALAMAN BASEMENT DI DARATAN PESISIR KECAMATAN WANGI-WANGI SELATAN KABUPAEN WAKATOBI." Jurnal Rekayasa Geofisika Indonesia 4, no. 01 (April 30, 2022): 35. http://dx.doi.org/10.56099/jrgi.v4i01.24156.
Full textAbstract:
Penelitian ini bertujuan untuk mengetahui kedalaman Basement di Kecamatan Wangi-Wangi Selatan Kabupaten Wakatobi berdasarkan sebaran spektrum HVSR data mikrotremor. Kedalaman Basement dapat diestimasi dengan menggunakan metode geofisika, salah satunya adalah dengan memanfaatkan data gelombang mikrotremor. Data mikrotremor dapat dianalisis dengan menggunakan metode Horizontal to Vertical Spectral Ratio (HVSR) yang merupakan sebagai indikator struktur bawah permukaan tanah yang memperlihatkan hubungan antara rasio spektrum Fourier dari sinyal mikrotremor komponen horisontal terhadap komponen vertikalnya. Nilai kedalaman Basement yang diperoleh dengan nilai terdangkal sebesar 6.23 m yang berada pada TP2 dan terdalam sebesar 140.80 m yang berada pada TP7. Hasil penelitian ini menunjukan bahwa berdasarkan nilai kedalaman Basement secara kualitatif daerah yang memiliki resiko tinggi mengalami kerusakan akibat gempabumi adalah kelurahan Kelurahan Liya Logo, Liya Mawi, Numana dan Kelurahan Mandati III.Kata kunci: Mikrotremor, HVSR, kedalaman Basement
46
Prabowo, Urip Nurwijayanto, Akmal Ferdiyan, and Ayu Fitri Amalia. "The Soft Layer Thickness Estimation using Microtremor Measurement to Identify Landside Potential in Watukumpul, Central Java, Indonesia." Journal of Geoscience, Engineering, Environment, and Technology 6, no. 1 (March 24, 2021): 16–23. http://dx.doi.org/10.25299/jgeet.2021.6.1.5436.
Full textAbstract:
Watukumpul is an area that is prone to landslides, so determining the soft layer thickness is very important to identify the landslide potential. The soft layer thickness can be estimated using microtremor signal measurements which analyzed using the Horizontal to Vertical Spectral Ratio (HVSR). In this study,we measured microtremor signal of 33location around Watukumpul, Pemalang, Central Java area to determine soft layer thickness. Micretremor signal was analyzed based on theHVSR method using Geopsy software and follow the standard of the Sesame Europan Project. The results of the HVSR method are the HVSR curve that fulfills the reliable curve standard. HVSR curve shows that the dominant frequency of soft layer ranges from 1.36 – 7.62 Hz and the amplification values ranges from 9.00 – 41.45. The soft layer thickness value in the study area ranges from 17.58 - 103.60 meters. The high landslide potential area are located at W7, W8, W18, W30 and W32 where has thin soft layer and high soil slope.
47
Capizzi, Patrizia, and Raffaele Martorana. "Analysis of HVSR Data Using a Modified Centroid-Based Algorithm for Near-Surface Geological Reconstruction." Geosciences 12, no. 4 (March 24, 2022): 147. http://dx.doi.org/10.3390/geosciences12040147.
Full textAbstract:
Recently, the use of microtremor techniques for subsoil investigation has increased significantly. The HVSR (Horizontal to Vertical Spectral Ratio) technique allows, in many cases, to obtain a seismo-stratigraphic reconstruction of the subsoil and to identify areas with similar seismic behavior. However, the stratigraphic interpretation of the HVSR peaks still remains a subjective choice and linked to a priori information. A non-hierarchical centroid-based algorithm was modified to group HVSR peaks of different measurements that can be attributed to the same generating seismic discontinuity. Some tests performed have shown that the proposed algorithm produces valid results even in the absence of a priori information to evaluate the choice of the optimal grouping. The results obtained for HVSR measurements acquired in the city of Modica (Italy) are presented. The cluster analysis of these data and the information on the lithologies outcropping in the area made it possible to reconstruct a 3D model of the main seismo-stratigraphic discontinuities.
48
Fattah, Elrangga Ibrahim. "Microzonation of Cisarua District Using Horizontal Vertical Spectral Ratio." Jurnal Ilmu dan Inovasi Fisika 5, no. 2 (August 9, 2021): 88–94. http://dx.doi.org/10.24198/jiif.v5i2.31533.
Full textAbstract:
The Bandung region is part of the framework of the Indonesian tectonic system, namely the tectonic plate meeting zone, where the Indo Autralia plate is infiltrated under the Eurasian plate in a convergent manner. The subduction process produces an effect in the form of an active fault geological structure in the Bandung area. One of these active faults is the Lembang Fault, which has a length of ± 29 kilometers and a shear acceleration of 3 to 5.5 millimeters per year. The microtremor measurement method is a passive geophysical method that utilizes natural subsurface vibrations so that it can provide dominant frequency data and amplification factors for soil layers. Based on the results of seismic susceptibility research using microtremor measurements using the HVSR method in the Lembang Fault zone in Cisarua Sub-District, it can be seen that the distribution of the dominant frequency values tends to be influenced by lithology and topography. In the research area, it is known to have a dominant frequency value that varies due to the different types of lithological units. In general, the dominant frequency ranges from 1-3 Hz because it is dominated by tuff sand and tuff pumice, and areas composed of volcanic breccias have a dominant frequency value between 3-6 Hz. Meanwhile, the amplification factor value will be influenced by rock deformation and weathering. The area that has a very high amplification factor value is in the southeast of the study area with an A0 value greater than 5. This indicates that the area is composed of a layer of thick and not dense tuff sand
49
Zulfakriza, Z., N. T. Puspito, A. D. Nugraha, B. Pranata, and S. Rosalia. "Preliminary Results of Horizontal to Vertical Spectral Ratio (HVSR) Across Lembang Fault, Bandung, Indonesia." IOP Conference Series: Earth and Environmental Science 273 (July 16, 2019): 012020. http://dx.doi.org/10.1088/1755-1315/273/1/012020.
Full text
50
Syaputra, Oky Dwi, Faizar Farid, Samsidar Samsidar, and Linda Handayani. "IDENTIFIKASI KELAYAKAN JEMBATAN BATANGHARI II KOTA JAMBI MENGGUNAKAN MIKROTREMOR DENGAN METODE HORIZONTAL TO VERTICAL SPECTRAL RATIO (HVSR)." Komunikasi Fisika Indonesia 16, no. 1 (April 30, 2019): 59. http://dx.doi.org/10.31258/jkfi.16.1.59-64.
Full textAbstract:
The feasibility study of Batanghari II Bridge with the value of natural frequency of Bridge using microtremor has been done. The purpose of this research is to know the bridge's natural frequency value using Horizontal to Vertical Spectral Ratio (HVSR) method and to know the relative damage to Bridge. In this study Bridge as an object because, Bridge is an alternative way that connects one place with another place separated by a river or ditch which is often used by society for activity. To get the bridge's natural frequency value using Microtremor sensor which is directly placed bridged with geopsy software to process its data and using HVSR method. The result of this research is the natural bridge frequency value of 7.40441 Hz. To determine the feasibility of the bridge compared with the standard value of the bridge frequency of 7,675 Hz and stated the state of the Batanghari II bridge is still intact from the structural and the natural frequency value of the soil on the bridge buffer of 12.7489 Hz and 13.6343 Hz that the soil type is older soil. Can be said the foundation of the bridge last long.