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Статті в журналах з теми "SHAPE OF TUNNEL"

1

Dhake, Shubham. "Tunneling in Various Shapes Using Numerical Analysis." International Journal for Research in Applied Science and Engineering Technology 9, no. VII (July 31, 2021): 3483–92. http://dx.doi.org/10.22214/ijraset.2021.37108.

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Анотація:
Tunnelling has gained popularity in the recent times due to lack of space and the rapidly increasing population. Thus, going underground is the only option to provide the infrastructure facilities which will meet the need of increasing population. The shape and dimensions of the tunnel cross section usually depends on certain parameters like purpose for which the tunnel is provided, drainage & maintenance requirements, requirement of escape route, etc. Geology plays an important role in deciding the shape of the tunnel. The ground behaves in a complex manner, when a tunnel is excavated in it as new stresses are developed. Based on the ground types, the shape is selected in such a way that the stresses developed in the ground should distribute properly around the tunnel periphery and should not cause convergence of the tunnel boundary. Also, requirement of support system should not be too heavy, as it will increase the cost. Apart from the above parameters, the availability of the equipment & the construction method also decides the shape of the tunnel. There are various shapes of tunnels like D-shape, Circular, Elliptical, Egg-shape, Box type, Horseshoe & Modified Horseshoe shape. In the present course of work three shapes of tunnels viz. Horseshoe Shape, Modified Horseshoe Shape & D-Shape tunnels are considered. By hypothetical assumption the geology and overburden are taken into account for the tunnels and the tunnels are simulated for roof collapse and shear failure case by using RS2 FEM based software.
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2

Cutler, Paul M. "Modelling the evolution of subglacial tunnels due to varying water input." Journal of Glaciology 44, no. 148 (1998): 485–97. http://dx.doi.org/10.3189/s002214300000201x.

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AbstractThe time evolution of a subglacial tunnel cross-section is examined usine a two-dimensional finite-element ice-flow model coupled to an idealized drainage system. Simulations are driven by physically based calculations of surface water-input variations at Slorgiaciaren, Sweden. Highlights of the model are its ability to handle unsteady conditions and irregular tunnel shapes. Agreement between modelled water pressure and borehole water levels is good. The following conclusions are reached: (i) Tunnels adapt to fluctuating inflow on time-scales of days. Storms, during which effective pressure ranges from 0 to 0.9 MPa, cause significant adjustments but daily fluctuations due solely to melt-water inflow are minor, (ii) Open-channel flow may become commonplace late in the ablation season, (iii) Initial tunnel shape influences subsequent tunnel evolution and seasonal water-pressure variation. Over the course of a summer, tunnels retain some of their initial shape, though in all experiments the width-to-height ratio increased with time, (iv) Tunnel contraction forms broad low tunnels. However, (v) given two tunnels of equal initial area, the higher narrower one expands more rapidly. Thus, more semi-circular tunnels may capture How from broader neighbours early in the summer.
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Cutler, Paul M. "Modelling the evolution of subglacial tunnels due to varying water input." Journal of Glaciology 44, no. 148 (1998): 485–97. http://dx.doi.org/10.1017/s002214300000201x.

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Анотація:
AbstractThe time evolution of a subglacial tunnel cross-section is examined usine a two-dimensional finite-element ice-flow model coupled to an idealized drainage system. Simulations are driven by physically based calculations of surface water-input variations at Slorgiaciaren, Sweden. Highlights of the model are its ability to handle unsteady conditions and irregular tunnel shapes. Agreement between modelled water pressure and borehole water levels is good. The following conclusions are reached: (i) Tunnels adapt to fluctuating inflow on time-scales of days. Storms, during which effective pressure ranges from 0 to 0.9 MPa, cause significant adjustments but daily fluctuations due solely to melt-water inflow are minor, (ii) Open-channel flow may become commonplace late in the ablation season, (iii) Initial tunnel shape influences subsequent tunnel evolution and seasonal water-pressure variation. Over the course of a summer, tunnels retain some of their initial shape, though in all experiments the width-to-height ratio increased with time, (iv) Tunnel contraction forms broad low tunnels. However, (v) given two tunnels of equal initial area, the higher narrower one expands more rapidly. Thus, more semi-circular tunnels may capture How from broader neighbours early in the summer.
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4

Dang, Van Kien, Ngoc Anh Do, Tai Tien Nguyen, Anh Duy Huynh Nguyen, and Van Vi Pham. "An overview of research on metro tunnel lining in the sub-rectangular shape." Journal of Mining and Earth Sciences 62, no. 4 (August 31, 2021): 68–78. http://dx.doi.org/10.46326/jmes.2021.62(4).08.

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Анотація:
Circular tunnels are the most popular shapes used in urban underground transportation systems when mechanized tunneling is used for tunnel excavation. However, circular tunnels have a small space utilization ratio. With the material development, non - circular tunnels such as sub - rectangular, U - shaped lining, etc. are now common, and their cross - section helps to improve the underground space utilization. However, there have been not many studies on the structure and the calculation method of the metro tunnels with the above cross - sections. The paper uses the analytical synthesis method to find out the advantages and disadvantages, the application conditions of the sub - rectangular shape, as well as the development direction for the complete calculation methods for this cross - section in Vietnamese conditions.
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Lin, Da Ming, Yan Jun Shang, Guo He Li, and Yuan Chun Sun. "Numerical Analysis of Damage for Y-Shape Tunnel." Advanced Materials Research 368-373 (October 2011): 2517–20. http://dx.doi.org/10.4028/www.scientific.net/amr.368-373.2517.

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There are many effective researches about tunnel at home and abroad, because the complexity of design and construction for Y-shape tunnel, in public there is no research about it yet, with the background of nanliang-tunnel which merge two single-beam into a two-lane tunnel as Y-shape. This paper obtains the rock mass mechanics parameters on the basis of nonlinear Hoek-Brown criterion first, and has a numerical simulation according the tunnel construction with FLAC-3D. we arrange many monitor sections in this model and discuss the law of deformation and failure in different section, at last have a comprehensive analysis of displacement, stress, plastic zone of different sites which caused by tunnel construction and discover that: with the distance of two single tunnels decreased, the interaction caused by the merging increase together with the compressive stress, tensile stress. The displacements of surrounding rock increase corresponding, the amplitude of variation is up to 44.8%, After the two-lane tunnel is 15m long, the stress and displacements redistribution of surrounding rock become stable.
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Zhang, Chengping, and Kaihang Han. "Collapsed Shape of Shallow Unlined Tunnels Based on Functional Catastrophe Theory." Mathematical Problems in Engineering 2015 (2015): 1–13. http://dx.doi.org/10.1155/2015/681257.

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This paper investigates the collapse mechanisms and possible collapsing block shapes of shallow unlined tunnels under conditions of plane strain. The analysis is performed following the framework from a branch of catastrophe theory, functional catastrophe theory. First, the basic principles of functional catastrophe theory are introduced. Then, an analytical solution for the shape curve of the collapsing block of a shallow unlined tunnel is derived using functional catastrophe theory based on the nonlinear Hoek-Brown failure criterion. The effects of the rock mass parameters of the proposed method on the shape and weight of the collapsing block are examined. Moreover, a critical cover depth expression to classify deep and shallow tunnels is proposed. The analytical results are consistent with those obtained by numerical simulation using the particle flow code, demonstrating the validity of the proposed analytical method. The obtained formulas can be used to predict the height and width of the collapsing block of a shallow unlined tunnel and to provide a direct estimate of the overburden on the tunnel lining. The obtained formulas can be easily used by tunnel engineers and researchers due to their simplicity.
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7

Jearsiripongkul, Thira, Suraparb Keawsawasvong, Chanachai Thongchom, and Chayut Ngamkhanong. "Prediction of the Stability of Various Tunnel Shapes Based on Hoek–Brown Failure Criterion Using Artificial Neural Network (ANN)." Sustainability 14, no. 8 (April 11, 2022): 4533. http://dx.doi.org/10.3390/su14084533.

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In this paper, artificial neural network (ANN) models are presented in order to enable a prompt assessment of the stability factor of tunnels in rock masses based on the Hoek–Brown (HB) failure criterion. Importantly, the safety assessment is one of the serious concerns for constructing tunnels and requires a reliable and accurate stability analysis. However, it is challenging for engineers to construct finite element limit analysis (FELA) algorithms with the HB failure criterion for tunnel stability solutions in rock masses. For the first time, a machine-learning-aided prediction of tunnel stability based on the HB failure criterion is proposed in this paper. Three different shapes of tunnels, i.e., heading tunnel, dual square tunnels, and dual circular tunnels, are considered. The inputs include four dimensionless parameters for the heading tunnel including the cover-depth ratio, the normalized uniaxial compressive strength, the geological strength index (GSI), and the mi parameter. Moreover, dual square and circular tunnels include one more additional parameter namely the distance ratio. The results present the best ANN models for each tunnel shape, providing very reliable solutions for predicting the tunnel stability based on the HB failure criterion.
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Mandal, Jagriti, ManmohanDass Goel, and AjayKumar Agarwal. "Effect of Horizontal Curve on the Response of Road Tunnels under Internal Explosion." Proceedings of the 12th Structural Engineering Convention, SEC 2022: Themes 1-2 1, no. 1 (December 19, 2022): 1293–97. http://dx.doi.org/10.38208/acp.v1.653.

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Internal explosion in a tunnel is a complex loading phenomenon where the tunnel lining is subjected to not only direct impact of explosion but also loading due to multiple reflection of blast waves which could be of magnitude higher than that of incident blast wave. This kind of loading is complex in nature and difficult to predict using simple analysis tools. Further, it poses a serious threat to its structural integrity. Studies have been conducted in the past to understand the behaviour of tunnel under internal explosion. However, they have been focused on straight tunnels ignoring the convex and concave shapes introduced due to horizontal and vertical curves. Shape of the target surface has significant effect on the characteristics of blast wave. This study investigates the effect of horizontal curves on the damage behaviour of tunnel lining due to internal explosion. A series of numerical simulation are performed on box-shaped tunnel with varying curvature radius and the results are compared with that of straight tunnel adopting Multi-Material Arbitrary Lagrangian-Eulerian (MM-ALE) method using LS-DYNA®. Explosive and air are modeled using ALE formulation, whereas, tunnel and soil are modeled using Lagrangian formulation. Further, Jones-Wilkins-Lee equation of state is used to model the explosion. Damage to the tunnel lining is measured in terms of peak particle velocity (PPV) and von-Mises stress. It is observed that walls of curved tunnels undergo more PPV compared with straight tunnel wherein concave wall show the highest PPV. Propagation of blast wave along the tunnel length is significantly affected due to the introduction of curvature resulting in change in reflection patterns. This further leads to variation in stress contours on tunnel lining with higher concentration of stress in curved tunnels than in straight tunnel.
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9

Wang, Shi Min, Chuan He, Si Jin Liu, and Lei Lei Lan. "Study on the Construction Mechanic Behaviors of Different Cross-Section Shape Connected Aisle in the Shield Tunnel with High Hydraulic Pressure." Advanced Materials Research 243-249 (May 2011): 3472–75. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.3472.

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With the construction of large quantities of shield tunnels, based on the consideration of the performance, disaster prevention, relief and tunnel drainage requirement, it becomes more and more important to set the connected aisle in the shield tunnel section. The shape of the connected aisle cross-section has an obvious effect on the deformation and stress of the connected aisle. In order to draw reasonable connected aisle type for the subway construction under high hydraulic conditions, the comparative analysis of stress state of the circular and horseshoe-shaped connected aisle section is applied based on the construction of the connected aisle in the shield tunnel across the Yangtze River in Wuhan subway. It is recommended that the horseshoe-shaped cross-section should be applied to connected aisle construction in the shield tunnel in Wuhan subway.
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10

Khan, Babar, Syed Muhammad Jamil, Jung Joo Kim, Turab H. Jafri, and Jonguk Kim. "Rock Mass Behavior under Tunnel Widening in Asymmetric and Symmetric Modes Considering Different Shapes and Parametric Conditions." Geosciences 9, no. 12 (December 16, 2019): 518. http://dx.doi.org/10.3390/geosciences9120518.

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To accommodate traffic volume on roads due to ever-increasing population growth, the widening of highways and motorways is in high demand. Nevertheless, the widening of tunnels on these road networks is quite complex due to the presence of numerous rock types, in situ stress, and different widening modes. To overcome these complexities, eight different tunnel shapes were simulated under varying support conditions for asymmetric and symmetric widening. It was found that the tunnels with a round shape, such as horseshoe and semicircular with flatbed, are more effective for asymmetric widening, whereas the provision of a rounded invert in these shapes can reverse the widening option to symmetric. Furthermore, an insignificant effect of the difference in asymmetric and symmetric widening of regular tunnel shapes, such as box, rectangular, and semi-elliptical, was found. A full factorial design statistical analysis confirmed the decrease in tunnel deformation by using various tunnel support systems and showed a significant deformation difference according to monitoring locations at the tunnel periphery. The deformation difference in the case of both tunnel widening modes was also analyzed according to different design parameters. This study provides a comprehensive understanding of rock mass behavior when the widening of any underground opening is carried out.
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Дисертації з теми "SHAPE OF TUNNEL"

1

Montero, Ryan M. "Analysis, Design and Testing of a Wind Tunnel Model to Validate Fiber-Optic Shape Sensing Systems." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/23233.

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The ability to collect valuable data concerning the stress, strains, and shape profiles of aircraft and aircraft components during flight is important to fields such as structural health monitoring, gust alleviation, and flutter control. A research interest in the form of a NASA Phase
I SBIR called for possible systems that would be able to take accurate shape sensing data on a flexible wing aircraft. In a joint venture between Luna Technologies Inc. and Virginia
Polytechnic Institute and State University a flexible wing wind tunnel model was designed and constructed as a test article for the Luna Technologies Inc. fiber optic shape sensing system. In order to prove the capability of a fiber optic shape sensing system in a wind tunnel environment a flexible wing test article was constructed. The wing deflections and twists of the test article were modeled using a vortex lattice method called Tornado combined with simple beam theories. The beam theories were linear beam theories and the stiffness of the composite bodies was supplied by static testing of the test articles. The code was iterative in that it ran the VLM code to estimate the forces and moments on the wing and these were applied to a linear beam which gave the wing a new geometry which in turn was run through the VLM. The wind tunnel model was constructed at Virginia Tech using 3-D printing techniques for the fuselage and foam and fiberglass for the wings. On the bottom surface of the wings the Luna Technologies Inc. fiber optic shape sensing fiber was bonded along the leading and tailing edges. The swept-wing test article was experimentally tested in the Virginia Tech 6\'x6\' Stability Wind Tunnel at various airspeeds and the VLM based code results were in agreement, within margins of error and uncertainty, with the experimental results. The agreement of the analytical and experimental results verified the viability of using an iterative VLM code in combination with simple beam theories as a quick and relatively accurate approximation method for preliminary design and testing. The tests also showed that a fiber optic shape sensing system can be sufficiently tested in a wind tunnel environment, and if applied carefully could perhaps in the future provide useful shape and strain measurements.

Master of Science
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2

Maesta, Marcelo Francisco. "Controle angular ativo de um aerofólio adaptativo utilizando fios de liga de memória de forma /." Ilha Solteira, 2016. http://hdl.handle.net/11449/148858.

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Orientador: Vicente Lopes Junior
Resumo: A busca por aeronaves capazes de modificar sua geometria melhorando suas características aerodinâmicas incentivou diversos autores a sugerirem modelos de asas adaptativas. Tais modelos utilizam atuadores leves de modo a substituir os atuadores clássicos convencionais sem, no entanto, comprometer a e ciência de voo da aeronave. Dentre os materiais utilizados para isto se destacam as ligas de memória de forma (Ni-Ti), que são capazes de converter energia térmica em energia mecânica e, uma vez deformadas, podem retornar a sua condição original de forma através de seu aquecimento. Neste contexto, o presente trabalho objetiva controlar a posição angular de um aerofólio utilizando para isto um par de os de liga de memória de forma. No modelo de asa proposto, deseja-se estabelecer uma forma para o per l aerodinâmico a partir da determinação de um ângulo entre duas seções da asa. Este ângulo é atingido pelo efeito de memória de forma da liga através da passagem de uma corrente elétrica. A função da corrente elétrica é alterar a temperatura dos atuadores através do efeito Joule, modificando a forma da liga. Devido à presença de efeitos não-lineares, principalmente no modelo matemático da liga, propõe-se a aplicação de controladores não-lineares do tipo liga-desliga.
Doutor
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3

Maestá, Marcelo Francisco [UNESP]. "Controle angular ativo de um aerofólio adaptativo utilizando fios de liga de memória de forma." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/148858.

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Submitted by MARCELO FRANCISCO MAESTÁ null (mfmaesta@gmail.com) on 2017-02-22T00:41:17Z No. of bitstreams: 1 Tese MArcelo Francisco Maesta.pdf: 11803249 bytes, checksum: c99c02808167e733ec292281a2b8c183 (MD5)
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Made available in DSpace on 2017-02-24T18:06:13Z (GMT). No. of bitstreams: 1 maestra_mf_dr_ilha.pdf: 11803249 bytes, checksum: c99c02808167e733ec292281a2b8c183 (MD5) Previous issue date: 2016-12-21
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
A busca por aeronaves capazes de modificar sua geometria melhorando suas características aerodinâmicas incentivou diversos autores a sugerirem modelos de asas adaptativas. Tais modelos utilizam atuadores leves de modo a substituir os atuadores clássicos convencionais sem, no entanto, comprometer a e ciência de voo da aeronave. Dentre os materiais utilizados para isto se destacam as ligas de memória de forma (Ni-Ti), que são capazes de converter energia térmica em energia mecânica e, uma vez deformadas, podem retornar a sua condição original de forma através de seu aquecimento. Neste contexto, o presente trabalho objetiva controlar a posição angular de um aerofólio utilizando para isto um par de os de liga de memória de forma. No modelo de asa proposto, deseja-se estabelecer uma forma para o per l aerodinâmico a partir da determinação de um ângulo entre duas seções da asa. Este ângulo é atingido pelo efeito de memória de forma da liga através da passagem de uma corrente elétrica. A função da corrente elétrica é alterar a temperatura dos atuadores através do efeito Joule, modificando a forma da liga. Devido à presença de efeitos não-lineares, principalmente no modelo matemático da liga, propõe-se a aplicação de controladores não-lineares do tipo liga-desliga.
The search for aircraft capable of modifying its geometry improving its aerodynamic characteristics, encouraged several authors to suggest models of adaptive wings. These models use lightweight actuators to replace conventional classic actuators without, however, compromise aircraft flight efficiency. Shape Memory Alloys (SMA) can be used efficiently for this application. These materials are capable of converting thermal energy into mechanical energy and a deformed time, can return to its original condition so through its heating. The current work aims to control the angular position of an airfoil using a couple of alloy wires of shape memory. In the proposed wing model, it is desired to establish a way for the aerodynamic pro le of the determination of an angle between two sections of the wing. This angle is attained by the alloy shape memory effect by passing an electric current. The function of the electric current is to change the temperature of the actuators through the Joule effect, modifying the shape of the shape memory alloy. Due to the presence of non-linear effects, especially in the mathematical model of the alloy, it proposes the application of nonlinear controllers type on-of
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Aristorenas, George V. (George Villanueva). "Time-dependent behavior of tunnels excavated in shale." Thesis, Massachusetts Institute of Technology, 1992. http://hdl.handle.net/1721.1/13197.

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5

Suratanakavikul, Varangrat. "Computational study of compressible flow in an S-shaped duct." Thesis, Imperial College London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313370.

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6

Li, Kuiyu. "Computing Homological Features for Shapes." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1282072779.

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7

Didascalou, Dirk [Verfasser]. "Ray optical wave propagation modelling in arbitrarily shaped tunnels / Dirk Didascalou." Karlsruhe : IHE, 2000. http://d-nb.info/1005259321/34.

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Fan, Fengtao. "Computing Topological Features of Data and Shapes." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1385999908.

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Crosariol, Victor A. "Scale Model Shake Table Testing of Underground Structures in Soft Clay." DigitalCommons@CalPoly, 2010. https://digitalcommons.calpoly.edu/theses/322.

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Underground structures perform an important role in transportation systems in many seismically active regions around the world, but empirical data regarding the seismic behavior of these structures is limited. This research works towards filling that empirical gap through the use of scale model shake table testing. Underground seismic soil-structure interaction (USSSI) effects were investigated for a stiff rectangular tunnel cross-section embedded within soft clay. San Francisco Young Bay Mud was used as a prototype soil for developing a scale model soil mixture consisting of kaolinite, bentonite, class C fly ash, and water. A single cell Bay Area Rapid Transit (BART) cut-and-cover subway tunnel was used as the prototype for the 10th scale model subway cross-section. A flexible walled test container originally developed for a pile study at UC Berkeley was modified for use at Cal Poly, San Luis Obispo. The flexible container allows for close approximation of one-dimensional (1D) free-field site response by significantly limiting the rigidity of the boundary conditions and allowing the soil to deform under simple shear. The study was conducted over two shake table testing phases: Phase I consisted of shaking a model soil column to evaluate the ability of the test container to produce adequate 1D free-field site response, and Phase II tests explored the horizontal racking distortion of a shallow rectangular tunnel cross-section subjected to strong transverse ground shaking. Phase I test results and comparison with SHAKE models indicate that the test container can sufficiently mimic 1D free-field conditions, specifically for the primary shear deformation mode. Similarly, the equivalent linear soil-structure interaction code FLUSH was found to adequately model site response for the Phase II soil-structure system. Comparison of recorded horizontal racking distortions of the model structure with those from numerical modeling suggest that current simplified design methods may overestimate distortions to some degree for cases similar to those examined in this research. Overall, the flexible wall testing container shows promise as a viable means for gaining further insight into USSSI topics, as well as various other geotechnical and soil-structure interaction problems.
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10

Larson, Christopher Whitford. "The Design and Construction of a 20" x 20" Mach 2.0 Blowdown Wind Tunnel to Characterize the Lift and Drag of Irregularly Shaped Fragments." Thesis, Virginia Tech, 2011. http://hdl.handle.net/10919/76968.

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A supersonic wind tunnel, with a 20" x 20'" test section cross sectional area, was designed and constructed at the Techsburg Wind Tunnel Facility in order to determine the lift and drag on irregularly shaped fragments in supersonic flow. Prior to beginning the wind tunnel design process, a blowdown analysis model was created in order to determine the influence of a number of parameters on tunnel run time and test gas properties throughout the tunnel circuit. The design of the settling chamber, test section, supersonic nozzles, diffuser, and exhaust are presented in this thesis. Diffuser performance has a large influence on wind tunnel efficiency and run time. Therefore, significant efforts should be taken in order to attain the highest possible pressure recovery within the diffuser. The design of wind tunnel components, as well as their stress analysis, was conducted using SolidWorks. The control valve and silencer were sized and selected for the expected tunnel operating conditions. Since the control valve tends to encompass a significant portion of the overall tunnel cost, care must be taken to ensure it has a large enough flow capacity to produce the desired test conditions. Also, attempts must be made to accurately predict the total pressure loss through the silencer, since this loss can have a large impact on the total pressure ratio necessary to produce the design Mach number. Upon completion of the design process, the supersonic wind tunnel was assembled, and shakedown testing was conducted. During shakedown testing it was determined that the wind tunnel was capable of producing Mach 2 flow in the test section. Following shakedown testing, a flow survey was conducted in order to ensure uniform Mach number flow exists throughout the region occupied by the fragments. Based on the flow survey it was determined that within the middle 60% of the test section, the average Mach number was 1.950 and varied by only 0.56% within this region. Two irregularly shaped fragments were tested at Mach 2 flow, over an effective 360° pitch sweep, with wind tunnel runs performed every 10 degrees. Based on the measured force data for both fragments, the lift appeared to follow a sinusoidal curve, with minimum values at 0, 90, and 180° balance pitch angle, and maximum values occurring around 45 and 135° pitch angle. The drag force was observed to follow a gradual curve with minimum values at 0 and 180° balance pitch angle, as expected since the fragment presented area is generally least in this orientation. The maximum drag was found to occur at a balance pitch angle of 90°, once again as expected since the fragment presented area is generally greatest at this angle. It was also observed that the fragment drag tended to be greater for a fragment orientation which places the concave side of the fragment into the direction of the flow.
Master of Science
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Книги з теми "SHAPE OF TUNNEL"

1

W, Moses Robert, and Langley Research Center, eds. A feasibility study to control airfoil shape using THUNDER. Hampton, Va: National Aeronautics and Space Administration, Langley Research Center, 1997.

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2

Mario, Vargas, and United States. National Aeronautics and Space Administration., eds. A laser-based ice shape profilometer for use in icing wind tunnels. [Washington, D.C.]: National Aeronautics and Space Administration, 1995.

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Mario, Vargas Meza, and United States. National Aeronautics and Space Administration., eds. A laser-based ice shape profilometer for use in icing wind tunnels. [Washington, D.C.]: National Aeronautics and Space Administration, 1995.

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4

Mario, Vargas, and United States. National Aeronautics and Space Administration., eds. A laser-based ice shape profilometer for use in icing wind tunnels. [Washington, D.C.]: National Aeronautics and Space Administration, 1995.

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Mario, Vargas, and United States. National Aeronautics and Space Administration., eds. A laser-based ice shape profilometer for use in icing wind tunnels. [Washington, D.C.]: National Aeronautics and Space Administration, 1995.

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6

M, Berkowitz Brian, and United States. National Aeronautics and Space Administration., eds. Experimental ice shape and performance characteristics for a multi-element airfoil in the NASA Lewis Icing Research Tunnel. [Washington, DC]: National Aeronautics and Space Administration, 1991.

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J, Simoneau Robert, Ching Chang Y, and United States. National Aeronautics and Space Administration., eds. Influence of turbulence parameters, Reynolds number, and body shape on stagnation-region heat transfer. [Washington, DC]: National Aeronautics and Space Administration, 1994.

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8

Cook, M. Systems tunnel linear shaped charge lightning strike: Final test report. Brigham City, UT: Thiokol Corp., Space Operations, 1989.

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9

Randall, Peterson, and Ames Research Center, eds. Shake test results of the MDHC test stand in the 40- by 80-foot wind tunnel. Moffett Field, Calif: National Aeronautics and Space Administration, Ames Research Center, 1994.

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L, Peterson Randall, and Ames Research Center, eds. Shake test results of the MDHC test stand in the 40- by 80-foot wind tunnel. Moffett Field, Calif: National Aeronautics and Space Administration, Ames Research Center, 1994.

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Частини книг з теми "SHAPE OF TUNNEL"

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Nastac, Laurentiu, and John Romanelli. "Advanced Casting Mold Design Technology of the LCS Waterjet Inlet Tunnel Entry Edge Components." In Shape Casting, 249–56. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2011. http://dx.doi.org/10.1002/9781118062050.ch30.

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Guisnet, M., S. Morin, and N. S. Gnep. "Evidence for a New Type of Shape Selectivity of Monodimensional Molecular Sieves: Tunnel-Shape Selectivity." In ACS Symposium Series, 334–52. Washington, DC: American Chemical Society, 1999. http://dx.doi.org/10.1021/bk-2000-0738.ch024.

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Brackmann, Lukas, Arne Röttger, Hoang-Giang Bui, Sahir Butt, Golnaz Hoormazdi, Abdiel Ramon Leon Bal, Sebastian Priebe, et al. "Excavation Simulations and Cutting Tool Wear." In Interaction Modeling in Mechanized Tunneling, 93–164. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-24066-9_3.

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AbstractThe mechanized tunnel construction is carried out by tunnel boring machines, in which the soil in front of the working face is removed, and the tunnel lining is carried out with shotcrete or the setting of segments and their back injection. Advancements in this field aim towards increase of the excavation efficiency and increase of the tool lifetime, especially in rock-dominated grounds. The latter is achieved by understanding the wear mechanisms abrasion and surface-fatigue, and by knowledge of the microstructure-property relation of the utilized materials. Improvements for tool concepts are derived, based on experiments and simulations. A key parameter towards efficient rock excavation is the shape of the cutting edge of the utilized disc cutters. Sharp cutting edges have proven to generate higher rock excavation rates compared to blunt ones. The compressive strength of the utilized steel has to be high, to inhibit plastic deformation and thereby to maintain sharp cutting edges. This requirement competes with the demand for toughness, which is necessary to avoid crack-growth in the case of cyclic loading. Solutions for this contradiction lie in specially designed multiphase microstructures, containing both hard particles and ductile microstructural constituents. Besides adapting the alloying concept, these required microstructures and the associated properties can be adjusted by specific heat-treatments.
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Feng, Bai, Yan Wei, and Li Haixing. "The Research of Correlationship and Critical Ice Shape Acquisition in CIRA-IWT Icing Wind Tunnel." In Lecture Notes in Electrical Engineering, 227–44. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-2689-1_17.

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Lee, Seong Wook, Tae Won Ahn, Dong Seop Han, Tae Hyung Kim, and Geun Jo Han. "The Structural Stability Analysis of a Container Crane According to the Boom Shape Using Wind Tunnel Test." In Damage Assessment of Structures VII, 365–72. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-444-8.365.

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Li, Jianbin, Junguang Huang, Huawei Tong, and Shankai Zhang. "Study on Surface Deformation Model Induced by Shield Tunneling Based on Random Field Theory." In Lecture Notes in Civil Engineering, 440–54. Singapore: Springer Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-1260-3_40.

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AbstractBased on the shield tunnel engineering in weathered granite stratum in Xiamen, Stochastic calculations, by combining the random field theory and the finite difference analysis together with Monte Carlo simulation, are used to carry out the change law of the characteristics of surface deformation curve and surface deformation model. Results show that with the increase of the vertical scales of fluctuation, the decrease of the transverse scales of fluctuation or the increase of the coefficient of variation, the low peak distribution characteristics of the location of the maximum surface settlement induced by shield tunneling become more obvious, and the randomness and chaos of the shape of surface deformation curve gradually increase. The diversity of surface deformation model is affected by parameter correlation and randomness. Under the condition of small transverse scales of fluctuation and large vertical scales of fluctuation, the sensitivity of coefficient of variation to surface deformation mode is limited.
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Gao, Ang, Xiufeng Wu, Shiqiang Wu, Hongpeng Li, Jiangyu Dai, and Fangfang Wang. "Study on Wind Waves Similarity and Wind Waves Spectrum Characteristics in Limited Waters." In Lecture Notes in Civil Engineering, 1220–35. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-6138-0_107.

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AbstractWind waves is an important factor affecting navigation safety and water environment in limited waters such as lakes and bays. Wind wave spectrum represents the frequency domain features of wind waves and has always been the focus of research. Based on the field observation and flume experimental method, the system analysis of similarity of two kinds of situations, discussed nonlinear response of the relationship of the spectral shape parameter of balance field α, β and wind waves basic frequency between factors like wind speed, wind blowing fetch and water depth. By means of wind tunnel flume and prototype observation data of nonlinear regression analysis, The relation formulas of wind wave frequency prediction considering the comprehensive influence of wind speed, wind blowing fetch and water depth is established. Relevant research is of great significance for revealing the evolution characteristics of wind waves in limited waters and guiding navigation safety and water environment management.
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8

Morgan, Lynette. "Greenhouses and protected cropping structures." In Hydroponics and protected cultivation: a practical guide, 11–29. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781789244830.0002.

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Abstract This chapter focuses on greenhouses and protected cropping structures. Topics covered are glasshouses and plastic greenhouses, closed and semi-closed greenhouse structures, passive solar greenhouses, sustainable greenhouse design, cladding materials, screen houses, net houses, shade houses, rain covers and other structures, screen and shade nets, low tunnels and high tunnels, hot beds and cold frames greenhouses, floating mulches, row covers, cloche covers, direct covers and frost cloth, greenhouse site planning, windbreaks, outdoor hydroponic systems, and controlled-environment agriculture.
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Morgan, Lynette. "Greenhouses and protected cropping structures." In Hydroponics and protected cultivation: a practical guide, 11–29. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781789244830.0011.

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Анотація:
Abstract This chapter focuses on greenhouses and protected cropping structures. Topics covered are glasshouses and plastic greenhouses, closed and semi-closed greenhouse structures, passive solar greenhouses, sustainable greenhouse design, cladding materials, screen houses, net houses, shade houses, rain covers and other structures, screen and shade nets, low tunnels and high tunnels, hot beds and cold frames greenhouses, floating mulches, row covers, cloche covers, direct covers and frost cloth, greenhouse site planning, windbreaks, outdoor hydroponic systems, and controlled-environment agriculture.
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Behera, Amar Kumar, Daniel Afonso, Adrian Murphy, Yan Jin, and Ricardo Alves de Sousa. "Accuracy Analysis of Incrementally Formed Tunnel Shaped Parts." In Communications in Computer and Information Science, 40–49. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-13-2396-6_4.

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Тези доповідей конференцій з теми "SHAPE OF TUNNEL"

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Wang, R., C. W. W. Ng, and T. Boonyarak. "Effect of an Existing Tunnel Shape on Crossing Tunnels’ Interaction." In Geotechnical Frontiers 2017. Reston, VA: American Society of Civil Engineers, 2017. http://dx.doi.org/10.1061/9780784480441.053.

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Wang, Guanda, Yue Zhang, Zhe Huang, Jinkai Wang, Kun Zhang, Zhizhong Zhang, Youguang Zhang, and Weisheng Zhao. "Thermal Stable and Fast Perpendicular Shape Anisotropy Magnetic Tunnel Junction." In 2019 IEEE/ACM International Symposium on Nanoscale Architectures (NANOARCH). IEEE, 2019. http://dx.doi.org/10.1109/nanoarch47378.2019.181282.

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Gates, Alfred, Ronald Adrezin, and Fu-Shang Wei. "Thin body shape optimization technique using wind tunnel test data." In 37th Aerospace Sciences Meeting and Exhibit. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1999. http://dx.doi.org/10.2514/6.1999-836.

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Leifsson, Leifur, and Slawomir Koziel. "Surrogate-Based Shape Optimization of Low-Speed Wind Tunnel Contractions." In 42nd AIAA Fluid Dynamics Conference and Exhibit. Reston, Virigina: American Institute of Aeronautics and Astronautics, 2012. http://dx.doi.org/10.2514/6.2012-3344.

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5

Inoue, Fumihiro, Soonsu Kwoon, Takuya Uchiyama, Satoru Nakamura, and Yoshitaka Yanagihara. "Shape Control of Variable Guide Frame for Tunnel Wall Inspection." In 34th International Symposium on Automation and Robotics in Construction. Tribun EU, s.r.o., Brno, 2017. http://dx.doi.org/10.22260/isarc2017/0094.

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Wu, David W., and Hwang Choe. "Effects of Sensor Shape on Oscillating Pressure Measurements With Wind-Tunnel Test Confirmation." In ASME 2006 Pressure Vessels and Piping/ICPVT-11 Conference. ASMEDC, 2006. http://dx.doi.org/10.1115/pvp2006-icpvt-11-93942.

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This paper summarizes the effects of the pressure sensor shape on the dynamic oscillating pressure measurements when the pressure wave modulating along the steam/air flow path is to be characterized. In the study presented in the paper, a three-dimensional CFD model of the external flow around the protruding, dome-shaped sensor was developed to evaluate the effects of the sensor shape on the external flow pattern, and the detailed flow patterns were studied with this protruding, dome-shaped sensors and compared with the flow patterns for the flush mounted sensors. Then, a one-dimensional analysis was done to predict that the dynamic pressures measured with the protruding sensor do not require significant correction, and this was later supported by wind tunnel tests. The amplitude of the dynamic pressure measured on the protruding sensor was determined to be ranging from 0 to 8% higher than measured by a flush mounted pressure sensor. The frequency of the pressure wave is not affected by the presence of the protrusion.
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Chanyuen Ping, Huang Hongwei, and Zhao Yonghui. "The performance test of U-shape antenna applied in tunnel detection." In 2012 14th International Conference on Ground Penetrating Radar (GPR). IEEE, 2012. http://dx.doi.org/10.1109/icgpr.2012.6254843.

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Jinnai, B., J. Igarashi, K. Watanabe, T. Funatsu, H. Sato, S. Fukami, and H. Ohno. "High-Performance Shape-Anisotropy Magnetic Tunnel Junctions down to 2.3 nm." In 2020 IEEE International Electron Devices Meeting (IEDM). IEEE, 2020. http://dx.doi.org/10.1109/iedm13553.2020.9371972.

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Yan, Zhi-Rui, Cong Li, Jia-Min Guo, Hao-Feng Jiang, Jian-Ping Chen, and Yi-Qi Zhuang. "An Optimized GaAsSb/InGaAs Heterojunction L-shape Tunnel Field-Effect Transistor." In 2018 14th IEEE International Conference on Solid-State and Integrated Circuit Technology (ICSICT). IEEE, 2018. http://dx.doi.org/10.1109/icsict.2018.8564858.

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Vierhub-Lorenz, Valentin, Katharina Predehl, Sebastian Wolf, Christoph S. Werner, Frank Kühnemann, and Alexander Reiterer. "A multispectral tunnel inspection system for simultaneous moisture and shape detection." In Remote Sensing Technologies and Applications in Urban Environments IV, edited by Nektarios Chrysoulakis, Thilo Erbertseder, Ying Zhang, and Frank Baier. SPIE, 2019. http://dx.doi.org/10.1117/12.2533101.

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Звіти організацій з теми "SHAPE OF TUNNEL"

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King, E. L., A. Normandeau, T. Carson, P. Fraser, C. Staniforth, A. Limoges, B. MacDonald, F. J. Murrillo-Perez, and N. Van Nieuwenhove. Pockmarks, a paleo fluid efflux event, glacial meltwater channels, sponge colonies, and trawling impacts in Emerald Basin, Scotian Shelf: autonomous underwater vehicle surveys, William Kennedy 2022011 cruise report. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/331174.

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A short but productive cruise aboard RV William Kennedy tested various new field equipment near Halifax (port of departure and return) but also in areas that could also benefit science understanding. The GSC-A Gavia Autonomous Underwater Vehicle equipped with bathymetric, sidescan and sub-bottom profiler was successfully deployed for the first time on Scotian Shelf science targets. It surveyed three small areas: two across known benthic sponge, Vazella (Russian Hat) within a DFO-directed trawling closure area on the SE flank of Sambro Bank, bordering Emerald Basin, and one across known pockmarks, eroded cone-shaped depression in soft mud due to fluid efflux. The sponge study sites (~ 150 170 m water depth) were known to lie in an area of till (subglacial diamict) exposure at the seabed. The AUV data identified gravel and cobble-rich seabed, registering individual clasts at 35 cm gridded resolution. A subtle variation in seabed texture is recognized in sidescan images, from cobble-rich on ridge crests and flanks, to limited mud-rich sediment in intervening troughs. Correlation between seabed topography and texture with the (previously collected) Vazella distribution along two transects is not straightforward. However there may be a preference for the sponge in the depressions, some of which have a thin but possibly ephemeral sediment cover. Both sponge study sites depict a hereto unknown morphology, carved in glacial deposits, consisting of a series of discontinuous ridges interpreted to be generated by erosion in multiple, continuous, meandering and cross-cutting channels. The morphology is identical to glacial Nye, or mp;lt;"N-mp;lt;"channels, cut by sub-glacial meltwater. However their scale (10 to 100 times mp;lt;"typicalmp;gt;" N-channels) and the unique eroded medium, (till rather than bedrock), presents a rare or unknown size and medium and suggests a continuum in sub-glacial meltwater channels between much larger tunnel valleys, common to the eastward, and the bedrock forms. A comparison is made with coastal Nova Scotia forms in bedrock. The Emerald Basin AUV site, targeting pockmarks was in ~260 to 270 m water depth and imaged eight large and one small pockmark. The main aim was to investigate possible recent or continuous fluid flux activity in light of ocean acidification or greenhouse gas contribution; most accounts to date suggested inactivity. While a lack of common attributes marking activity is confirmed, creep or rotational flank failure is recognized, as is a depletion of buried diffuse methane immediately below the seabed features. Discovery of a second, buried, pockmark horizon, with smaller but more numerous erosive cones and no spatial correlation to the buried diffuse gas or the seabed pockmarks, indicates a paleo-event of fluid or gas efflux; general timing and possible mechanisms are suggested. The basinal survey also registered numerous otter board trawl marks cutting the surficial mud from past fishing activity. The AUV data present a unique dataset for follow-up quantification of the disturbance. Recent realization that this may play a significant role in ocean acidification on a global scale can benefit from such disturbance quantification. The new pole-mounted sub-bottom profiler collected high quality data, enabling correlation of recently recognized till ridges exposed at the seabed as they become buried across the flank and base of the basin. These, along with the Nye channels, will help reconstruct glacial behavior and flow patterns which to date are only vaguely documented. Several cores provide the potential for stratigraphic dating of key horizons and will augment Holocene environmental history investigations by a Dalhousie University student. In summary, several unique features have been identified, providing sufficient field data for further compilation, analysis and follow-up publications.
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EXPERIMENTAL STUDY ON WELDING RESIDUAL STRESS OF TWO-WAY STIFFENED STEEL PLATES. The Hong Kong Institute of Steel Construction, August 2022. http://dx.doi.org/10.18057/icass2020.p.531.

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The immersed tunnel of Shenzhen-Zhongshan Link Project adopts the steel shell-concrete (SSC) composite structure, in which the two-way stiffened steel plate is applied as the surface of steel shell. Since the steel plate stiffened in two-way, the residual stresses could be induced in the complicated welds at the intersections of plates and stiffeners. Therefore, residual stress experimental study on two full-scale specimen of the two-way stiffened steel plate, based on the steel shell details of ShenzhenZhongshan Link Project, was carried out to investigate the distribution of residual stresses by sectioning method. Results show that tensile residual stress could be measured near the welded stiffeners with a maximum of about 0.66 times the yield strength. While the compressive residual stress is between the stiffeners, with a maximum of about 0.35 times the yield strength. Furthermore, in the direction of welded T-shape stiffeners, the difference values between residual stresses of inner and outer surfaces on bottom plates is smaller than that in the direction of welded plate stiffeners, with maximum values of 0.09 times and 0.22 times the yield strength, respectively.
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