Статті в журналах: "Shallow footings"

1

Graham, J., M. Andrews, and D. H. Shields. "Stress characteristics for shallow footings in cohesionless slopes." Canadian Geotechnical Journal 25, no. 2 (May 1, 1988): 238–49. http://dx.doi.org/10.1139/t88-028.

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Footings placed at shallow depth in bridge approach embankments can be used to reduce the cost and to improve the performance of bridge supports. The embankments frequently terminate in slopes dropping to underpass level, and the footings therefore have lower capacity than that for footings on level ground. The needed design procedures have not been well validated.The paper describes a new solution using the method of stress characteristics for footing capacity in cohesionless slopes. The soil is assumed to have c = 0, [Formula: see text] = constant, γ > 0. Particular attention is paid to modelling the asymmetric nonfailing zone immediately beneath the footing. Solutions for various slope angles and friction angles have been obtained for footings placed at the crest of the slope with D/B = H/B = 0, and for H/B = 0.5, 1.0, and 2.0; D/B = 0.5 and 1.0. The theoretical bearing capacities are compared with experimental values from two series of laboratory tests. Key words: bearing capacity, footings, failure, bridge abutments, slopes, sand, cohesionless, stress characteristics.

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2

Turker, Emel, Erol Sadoglu, Evrim Cure, and Bayram Ali Uzuner. "Bearing capacity of eccentrically loaded strip footings close to geotextile-reinforced sand slope." Canadian Geotechnical Journal 51, no. 8 (August 2014): 884–95. http://dx.doi.org/10.1139/cgj-2014-0055.

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A series of bearing capacity tests were conducted with an eccentrically (e/B = 0, 1/12, 1/6, 1/3) loaded model surface (Df/B = 0) and shallow (Df/B = 0.25) strip footings (B = 80 mm) resting close to reinforced finite sand slopes to investigate ultimate loads, failure surfaces, load–displacement curves, rotation of footing, etc. The experimental set-up used to run the tests consists of a tank, model footing, sand, and a loading mechanism. A single woven geotextile strip sheet was placed horizontally below the footing’s base at a depth of half of the footing’s width. Ultimate loads decreased with increasing eccentricity. This decrease is due to a combination of eccentricity and slope. The use of geotextile reinforcement increased ultimate loads in comparison with unreinforced cases. Failure surfaces were not symmetrical, primary failure surfaces developed on the eccentricity (slope) side, and secondary failure surfaces developed on the other side. Lengths of failure surfaces decreased with increasing eccentricity. Prior to failure, footings always rotated towards the eccentricity (slope) side a few degrees.

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3

Shadmand, A., Mahmoud Ghazavi, and Navid Ganjian. "Scale Effects of Footings on Geocell Reinforced Sand Using Large-Scale Tests." Civil Engineering Journal 4, no. 3 (April 7, 2018): 497. http://dx.doi.org/10.28991/cej-0309110.

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The scale effect on bearing capacity of shallow footings supported by unreinforced granular soils has been evaluated extensively. However, the subject has not been addressed for shallow footings on geocell-reinforced granular soils. In this study, load-settlement characteristic of large square footings is investigated by performing large-scale loading tests on unreinforced and geocell-reinforced granular soils. The effects of footing width (B), soil relative density of soil (Dr), and reinforcement depth (u) have been investigated. The test results show that the scale effects exist in geocell-reinforced soils, like unreinforced soils, and the behavior of small-scale models of footings cannot be directly related to the behavior of full-scale footings due to the difference between initial conditions of tests and the initial state of mean stresses in the soil beneath the footings having different dimensions. Large footings create higher mean stresses in the soil, resulting in low soil friction angle and initial conditions of the test approach to the critical state lines. The results of tests indicate that model experiments should be conducted on low-density soil for better prediction of the behavior of full-scale footings, otherwise, the predicted behavior of full-scale footings does not seem conservative.

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4

Hakhamaneshi, Manouchehr, Bruce L. Kutter, Mark Moore, and Casey Champion. "Validation of ASCE 41-13 Modeling Parameters and Acceptance Criteria for Rocking Shallow Foundations." Earthquake Spectra 32, no. 2 (May 2016): 1121–40. http://dx.doi.org/10.1193/121914eqs216m.

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The standard ASCE 41-13 Seismic Evaluation and Retrofit of Existing Buildings includes new provisions for linear and non-linear modeling parameters and acceptance criteria for rocking shallow foundations. The new modeling parameters and acceptance criteria were largely based on model tests on rectangular rocking foundations with a limited range of footing length to width ratio (L/B). New model test results are presented, including a systematic variation of L/B and also non-rectangular (I-shaped) footings. This new data along with previously published results are presented to validate the trilinear modeling parameters and acceptance criteria of ASCE 41-13. This paper investigates the effects of footing shape on the residual settlement, residual uplift, rocking stiffness, and re-centering. Overall, the new data supports the provisions of ASCE 41-13; however, the acceptance limits for rocking rotation of I-shaped footings could be reduced to produce performance consistent with the acceptance limits for rectangular footings.

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5

Ausilio, Ernesto, and Enrico Conte. "Influence of groundwater on the bearing capacity of shallow foundations." Canadian Geotechnical Journal 42, no. 2 (April 1, 2005): 663–72. http://dx.doi.org/10.1139/t04-084.

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In this paper, the kinematic approach of limit analysis is used to analyse the influence of groundwater on the bearing capacity of shallow foundations. Analytical expressions are derived allowing the bearing capacity of strip footings resting on a soil where the water table is at some depth below the footing base to be calculated. Results from these expressions are compared with those obtained using other theoretical solutions available in literature. Moreover, a parametric study is carried out to illustrate the effects on bearing capacity of submergence of the soil below the footing. The importance of these effects is discussed, and remarks are also made on the results provided by some simplified methods that are currently used in practice. Finally, a simple approximation of the theoretical solution derived in this study is suggested for practical purposes.Key words: bearing capacity, limit analysis, groundwater, strip footings.

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6

Melchers, R. E. "Rotational stiffness of shallow footings." Computers and Geotechnics 13, no. 1 (January 1992): 21–35. http://dx.doi.org/10.1016/0266-352x(92)90009-i.

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7

Puzakov, Viktor, Andrew Drescher та Radoslaw L. Michalowski. "Shape factor sγfor shallow footings". Geomechanics and Engineering 1, № 2 (25 червня 2009): 113–20. http://dx.doi.org/10.12989/gae.2009.1.2.113.

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8

El-kady, Mahmoud Samir, and Essam Farouk Badrawi. "Performance of isolated and folded footings." Journal of Computational Design and Engineering 4, no. 2 (September 14, 2016): 150–57. http://dx.doi.org/10.1016/j.jcde.2016.09.001.

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Abstract Folded foundations have been used as an alternative to the conventional flat shallow foundations, in situations involving heavy loads or weak soils. They can be geometrically shaped in many forms especially for isolated footings. The purpose of this paper is introducing an alternative foundation shape that reduces the cost of foundations by reducing the amount of reinforcing steel by minimizing or even eliminating the tension zones in the folded isolated footings. Also, achieving lower soil stresses through changing the isolated footing shape will consequently reduce the expected settlements and the footing stresses. Experimental and numerical studies are performed on five (5) quarter scale footings of which one (1) footing of flat shape is tested as a reference sample and four (4) footings are of folded shape by folding angles of 10°, 20°, 30°, and 40° with the horizontal. Results showed that the folded isolated footings achieve economic design by decreasing the quantities of reinforcement. It also induced less soil settlements, and stresses. In addition, the tensile stresses in the reinforced concrete footing body are also less in folded isolated footings than the flat one. Results show that the folded isolated footing have a better load carrying capacity when compared with the conventional slab/flat footing of similar cross sectional area for both cases of experimental and numerical analysis. Highlights The purpose of this paper is achieving lower soil stresses through changing the isolated footing shape will consequently reduce the expected settlements and the footing stresses resulting from differential settlements. Experimental and numerical studies are perform using five (5) quarter scale footings of which one (1) footing of flat shape as a reference sample and four (4) footings are of folded shape by a folding angles of 10, 20, 30, and 40 degrees with the horizontal. The most effective and preferable value of the folding angle (?), is equal to 30 degrees. Good agreement is reached between the experimental and numerical results. Results showed that the maximum tensile stresses in steel bars decreased by about 48% for folded isolated footing case when compared with conventional flat ones

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9

Pantelidis, Lysandros. "Strain Influence Factor Charts for Settlement Evaluation of Spread Foundations based on the Stress–Strain Method." Applied Sciences 10, no. 11 (May 31, 2020): 3822. http://dx.doi.org/10.3390/app10113822.

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In this paper, the stress–strain method for the elastic settlement analysis of shallow foundations is revisited, offering a great number of strain influence factor charts covering the most common cases met in civil engineering practice. The calculation of settlement based on strain influence factors has the advantage of considering soil elastic moduli values rapidly varying with depth, such as those often obtained in practice using continuous probing tests, e.g., the Cone Penetration Test (CPT) and Standard Penetration Test (SPT). It also offers the advantage of the convenient calculation of the correction factor for future water table rise into the influence depth of footing. As is known, when the water table rises into the influence zone of footing, it reduces the soil stiffness and thus additional settlement is induced. The proposed strain influence factors refer to flexible circular footings (at distances 0, R/3, 2R/3 and R from the center; R is the radius of footing), rigid circular footings, flexible rectangular footings (at the center and corner), triangular embankment loading of width B and length L (L/B = 1, 2, 3, 4, 5 and 10) and trapezoidal embankment loading of infinite length and various widths. The strain influence factor values are given for Poisson’s ratio value of soil, ranging from 0 to 0.5 with 0.1 interval. The compatibility of the so-called “characteristic point” of flexible footings with the stress–strain method is also investigated; the settlement under this point is considered to be the same as the uniform settlement of the respective rigid footing. The analysis showed that, despite the effectiveness of the “characteristic point” concept in homogenous soils, the method in question is not suitable for non-homogenous soils, as it largely overestimates settlement at shallow depths (for z/B < 0.35) and underestimates it at greater depths (for z/B > 0.35; z is the depth below the footing and B is the footing width).

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10

Bienen, B., and M. J. Cassidy. "Three-dimensional numerical analysis of centrifuge experiments on a model jack-up drilling rig on sand." Canadian Geotechnical Journal 46, no. 2 (February 2009): 208–24. http://dx.doi.org/10.1139/t08-115.

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Jack-up drilling rigs are usually founded on three shallow footings. Under wind, wave, and current loading offshore, the footings of these tall multi-footing systems transfer large moment loads in addition to self-weight, horizontal load, and even torsion to the underlying soil. To be able to deploy a jack-up safely at a particular offshore site, the unit’s capacity to withstand a 50 year return period storm is required to be checked in accordance with current guidelines (Site specific assessment of mobile jack-up units, The Society of Naval Architects & Marine Engineers). As the overall system behaviour is influenced significantly by the footing restraint, models that account for the complex nonlinear foundation–soil interaction behaviour are required to be integrated with the structural and loading models. Displacement-hardening plasticity theory has been suggested as an appropriate framework to formulate force-resultant models to predict shallow foundation behaviour. Recent research has extended such a model to account for six degree-of-freedom loading of circular footings on sand, allowing integrated structure–soil analysis in three dimensions. This paper discusses “class A” numerical predictions of experiments on a model jack-up in a geotechnical centrifuge, using the integrated modelling approach, and critically evaluates the predictive performance. The numerical simulations are shown to represent a significant improvement compared with the method outlined in the current guidelines.

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11

Fattah, Mohammed Y., Mohammed A. Al-Neami, and Sadan A. Mohammed. "Settlement of Ring Footing Resting on Geocell Reinforced Sandy Soil under Cyclic Load." E3S Web of Conferences 318 (2021): 01003. http://dx.doi.org/10.1051/e3sconf/202131801003.

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Ring footings are widely used as a foundation for water tanks, television antennas, silos, chimneys, oil storage tanks, etc. This paper is conducted to study the ring footing model's experimental cyclic behavior and circular footing resting on sandy soil reinforced with geocell. A group of ninety-six test models has been tested to investigate shallow footings' behavior beneath a cyclic loading of various loading rates. Four shapes of footing sand with three relative densities, two embedment depths of footing, two loading rates, and two widths of geocell were used. It was founded that as the footing depth increases, the settlement of soil due to cyclic loading decreases. Generally, when other variables are maintained to be the same, the footing bearing capacity increases when the foundation depth increases. The footing rebounds to some degree during the decay period of the load. The presence of geocell at the footing depth equals 100 mm will provide more improvement in all footing models more than using it at the surface, especially in ring 2 where the radius ratio is 0.4.

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12

di Prisco, Claudio, and Federico Pisanò. "Seismic response of rigid shallow footings." European Journal of Environmental and Civil Engineering 15, sup1 (January 2011): 185–221. http://dx.doi.org/10.1080/19648189.2011.9695308.

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13

Arduino, Pedro, and Emir J. Macari. "Numerical Modeling of Spread Footings at Bridge–Embankment Interfaces." Transportation Research Record: Journal of the Transportation Research Board 1633, no. 1 (January 1998): 61–67. http://dx.doi.org/10.3141/1633-08.

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The use of spread footings on slopes is a common practice in the design of bridge foundations. Footings generally are constructed in the slope or at its crest to minimize the bridge length, thereby minimizing costs. However, the analytical methods that frequently are used to predict the ultimate bearing capacity of shallow spread footings on slopes yield a wide range of solutions. There has been an increased effort in recent years to evaluate and improve techniques for predicting the deformation and ultimate bearing capacity of shallow spread footings located on or near slopes. Research in the development of numerical techniques used in conjunction with sophisticated elastoplastic constitutive models continues to be an area in which additional effort is needed. Physical model tests were used to obtain maximum bearing pressures of shallow spread footings located near sand slopes. These results were compared with classical bearing capacity solutions and numerical predictions obtained with finite element discretizations. Deformed meshes and incremental nodal displacements are presented.

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14

Eissa, Raad. "Identification of Different Shallow Foundations Using 3D Electrical Resistivity Modeling." Iraqi Geological Journal 55, no. 2B (August 31, 2022): 111–20. http://dx.doi.org/10.46717/igj.55.2b.10ms-2022-08-26.

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The electrical resistivity method has been successfully used to detect shallow buried foundations, almost, by using 2D electrode arrays. Basic geometry foundations (e.g., buried walls) have been investigated, although, more complicated foundation designs (e.g., stepped footing, pile group with a pile cap) are widely used in the construction industry. Investigation of these complicated foundation types, and engaging 3D surveys, therefore, are required. Multiple 3D electrical resistivity forward modeling was used to simulate different foundations (isolated simple footing, isolated stepped footing, combined simple footings, and pile group with a pile cap). The generated data sets then inverted using a robust inversion algorithm where RES3DINVx64 was used to perform the inversion process for the 3D models. The results from the 3D inverse modeling, suggest the pole-dipole and dipole-dipole arrays for all the investigated foundations.

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15

Vianna, Ana P. F., José C. A. Cintra, and Nelson Aoki. "Influence of Footing Size and Matric Suction on the Behavior of Shallow Foundations in Collapsible Soil." Soils and Rocks 30, no. 3 (September 1, 2007): 127–37. http://dx.doi.org/10.28927/sr.303127.

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This work analyses the influence of footing size and soil matric suction on the behavior of shallow foundations on unsaturated sandy soil, in terms of bearing capacity and settlements. Fourteen plate load tests were performed at the Experimental Site of USP/São Carlos. Rigid metal plates were used, with diameters varying between 0.20 m and 0.80 m and reinforced concrete footings, with circular base diameter 1.50 m. All the plates and the footings were installed at a depth of 1.5 m. These tests were conducted either with matric suction monitoring using tensiometers installed at the bottom of the hole or with soil flooding. The important role of the matric suction was confirmed. A reduction of the matric suction close to zero causes a great decrease in the bearing capacity and a significant increase in the settlement. In relation to the footing size (B), the bearing capacity as well as the settlements did not present a constant linear increasing variation. This work also proved the importance of considering the soil collapsibility in unsaturated soil shallow foundations design. When this factor is not considered, the calculated allowable bearing capacity may cause very high settlements if soil flooding occurs.

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16

Arab, O. A., A. J. M. S. Lim, S. Y. Sim, and N. A. A. Guntor. "Numerical Modelling Observations of Settlement for Pad Footings Supported on Soft Clay Soil." IOP Conference Series: Materials Science and Engineering 1200, no. 1 (November 1, 2021): 012032. http://dx.doi.org/10.1088/1757-899x/1200/1/012032.

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Abstract Settlement calculation is an important part in the design of shallow foundations resting on soft soils. The size of the foundation, the depth of the footings, and the rise in ground water level are thought to influence settlement and have been the subject of much research for many years. Thus, this study compared several pad footing sizes using numerical techniques as the basis. The first objective of this study was to analyse soil and pad footing settlement, and to determine the optimal size of footing that withstands excessive settlement due to variation in the water table and the depth of the foundation. Three footing embedment depths of 1.5, 2, and 3m with three water table positions, at the GL (0m), 1.5, and 3m with an applied foundation concentrated load of 440 kN using five footing models of 1.5mx1.5m, 2mx1.5m, 2 m x 2 m, 2.5x1.5m, and 2.5x1.5m pad footing with a uniform thickness of 0.5m were considered. In this study, a 3D Plaxis simulation is used for predicting the settlement of shallow foundations on soft clay soils. Settlement results were discovered at various water table positions and foundation depths. The study found that the 2.5x2m footing was deemed the best among the simulated foundations, and the 3m foundation embedment was considered the best at shallow depths due to less excessive settlement than the other tested foundations. The settlement had a significant impact on the size of the foundation and the depth of the footing. The depth of the water table has a small impact on the settlement. Parametric analysis is also being used to gain a better understanding of the behaviour of the elastic settlement of various shallow foundations. It is found that the footing area increases, settlement decreases and vice versa.

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17

Singh, Chamjeet, Jagdeep Singh, Sandeep Singh, and Vikas Kumar. "Performance of Inclined Skirt Footing: Numerical Analysis." IOP Conference Series: Earth and Environmental Science 889, no. 1 (November 1, 2021): 012076. http://dx.doi.org/10.1088/1755-1315/889/1/012076.

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Abstract The skirt footings are considered as alternate to enhance the bearing capacity of shallow foundation on sandy soil as an alternate of deep foundation. The experimental data of paper titled “Performance of skirt strip footing subjected to eccentric inclined load was consider as base for validation and other parameters of material for numerical investigation for different conditions. Numerical analysis was conducted to determine the behavior of two-sided skirt footing on eccentric loading with different angle and projections provided to skirt. The study reveals good impact of skirt angle and skirt projection lengths on load capacity of footing system

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18

Georgiadis, Michael. "Load-Path Dependent Stability of Shallow Footings." Soils and Foundations 25, no. 1 (March 1985): 84–88. http://dx.doi.org/10.3208/sandf1972.25.84.

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19

Choudhury, Deepankar, and Kanakapura S. Subba Rao. "Seismic bearing capacity of shallow strip footings." Geotechnical and Geological Engineering 23, no. 4 (August 2005): 403–18. http://dx.doi.org/10.1007/s10706-004-9519-9.

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20

Khajehzadeh, Mohammad, Suraparb Keawsawasvong, and Moncef L. Nehdi. "Effective Hybrid Soft Computing Approach for Optimum Design of Shallow Foundations." Sustainability 14, no. 3 (February 6, 2022): 1847. http://dx.doi.org/10.3390/su14031847.

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In this study, an effective intelligent system based on artificial neural networks (ANNs) and a modified rat swarm optimizer (MRSO) was developed to predict the ultimate bearing capacity of shallow foundations and their optimum design using the predicted bearing capacity value. To provide the neural network with adequate training and testing data, an extensive literature review was used to compile a database comprising 97 datasets retrieved from load tests both on large-scale and smaller-scale sized footings. To refine the network architecture, several trial and error experiments were performed using various numbers of neurons in the hidden layer. Accordingly, the optimal architecture of the ANN was 5 × 10 × 1. The performance and prediction capacity of the developed model were appraised using the root mean square error (RMSE) and correlation coefficient (R). According to the obtained results, the ANN model with a RMSE value equal to 0.0249 and R value equal to 0.9908 was a reliable, simple and valid computational model for estimating the load bearing capacity of footings. The developed ANN model was applied to a case study of spread footing optimization, and the results revealed that the proposed model is competent to provide better optimal solutions and to outperform traditional existing methods.

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21

Sadiq, Ahmed Mohammed, and Bushra Suhale Albusoda. "Experimental and Theoretical Determination of Settlement of Shallow Footing on Liquefiable Soil." Journal of Engineering 26, no. 9 (September 1, 2020): 155–64. http://dx.doi.org/10.31026/j.eng.2020.09.10.

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A high settlement may take place in shallow footing when resting on liquefiable soil if subjected to earthquake loading. In this study, a series of shaking table tests were carried out for shallow footing resting on sand soil. The input motion is three earthquake loadings (0.05g, 0.1g, and 0.2g). The study includes a reviewing of theoretical equations (available in literatures), which estimating settlement of footings due to earthquake loading, calibration, and verification of these equations with data from the shaking table test for improved soil by grouting and unimproved soil. It is worthy to note that the grouting materials considered in this study are the Bentonite and CKD slurries. A modification to the seismic settlement equations, by statistical analysis using SPSS software, had been done to account for the liquefaction state. The modified equation showed a good convergence with the measured settlement values.

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22

Sarma, S. K., and I. S. Iossifelis. "Seismic bearing capacity factors of shallow strip footings." Géotechnique 40, no. 2 (June 1990): 265–73. http://dx.doi.org/10.1680/geot.1990.40.2.265.

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23

Meyerhof, George G., and Tatsuya Koumoto. "Inclination Factors for Bearing Capacity of Shallow Footings." Journal of Geotechnical Engineering 113, no. 9 (September 1987): 1013–18. http://dx.doi.org/10.1061/(asce)0733-9410(1987)113:9(1013).

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24

Budhu, Muniram. "Design of shallow footings on heavily overconsolidated clays." Canadian Geotechnical Journal 49, no. 2 (February 2012): 184–96. http://dx.doi.org/10.1139/t11-093.

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This paper presents an integrated bearing capacity–settlement approach to the design of shallow foundations on heavily overconsolidated clays by alterations of the “modified Cam clay” (MCC) model. The bearing capacity of soils and their settlements from loads imposed on shallow footings have been studied extensively. Yet, there is no consensus on a method that provides both reliable load-bearing capacity and settlement predictions. Current methods treat the soil under shallow footings as different ideal materials for the purpose of calculating the bearing capacity and settlement. The method proposed in this paper treats the soil as a single ideal material for both bearing capacity and settlement. The MCC model is tailored by adding Hvorslev’s findings on overconsolidated clays and delineating stress states that bring the soil to tensile failure from those that cause it to yield or behave elastically or to show discontinuous response. A limiting stress surface is established as defining a limiting bearing capacity. A heavily overconsolidated clay is assumed to behave elastically if its stress state is below the limiting stress surface. Predictions from the method proposed in this paper compare favorably with model tests and field test results. Examples are provided illustrating how to use the proposed method.

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25

Zedan, Adnan Jayed. "Assessment of Settlement of Shallow Foundations Erected Near Slopes of Sandy Soil." Tikrit Journal of Engineering Sciences 13, no. 4 (December 31, 2006): 35–54. http://dx.doi.org/10.25130/tjes.13.4.02.

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In this study, the behaviour of shallow foundations near slopes is studied using nonlinear elastic finite element analysis. Forty-four cases of strip footings resting on cohesionless soils that were studied by Sud (1984)[1] through model tests, have been analyzed. Pressure-settlement relations has been compared with experimental results of (Sud, 1984) [1], and a good agreement between the two has been observed. Ultimate bearing capacity of shallow foundations near slopes was evaluated using the intersection of two tangents of pressure-settlement curve. The values of ultimate bearing capacity agree well also with (Sud, 1984) [1]. A non-dimensional correlation has been developed between the settlement of footing erected near slope (Sβ) and the settlement of footing resting on level ground (So). The relationship (Sβ/So versus De/B) can be expressed by a unique relation for different slope angles (β). This relation has been found to be dependent on distance of the edge of the footing from slope shoulder; De, and angle of slope; β, while it is independent of the relative density of sand; DR, and the factor of safety. By knowing the settlement of a footing resting on a level ground, the settlement of a footing erected near slope can be evaluated using this correlation.

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26

Fenton, Gordon A., D. V. Griffiths, and W. Cavers. "Resistance factors for settlement design." Canadian Geotechnical Journal 42, no. 5 (October 1, 2005): 1422–36. http://dx.doi.org/10.1139/t05-053.

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To control serviceability problems arising from excessive settlement of shallow footings, geotechnical design codes generally include specifications regarding maximum settlement, which often govern the footing design. Once the footing has been designed and constructed, the actual settlement it experiences on a real three-dimensional soil mass can be quite different than expected, due to the soil's spatial variability. Because of this generally large variability (compared to other engineering materials, such as concrete and steel) and because this particular serviceability limit state often governs the design, it makes sense to consider a reliability-based approach to settlement design. This paper looks in some detail at a load and resistance factor design (LRFD) approach to limiting footing settlement. In particular, the resistance factors required to achieve a certain level of settlement reliability as a function of soil variability and site investigation intensity are determined analytically using random field theory. Simplified approximate relationships are proposed and tested using simulation via the random finite element method. It is found that the simplified relationships are validated both by theory and simulation and so can be used to augment the calibration of geotechnical LRFD code provisions with respect to shallow foundation settlement. Key words: reliability-based design, settlement, geotechnical, shallow foundation, random field, probability.

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27

Cascone, E., G. Biondi, and O. Casablanca. "Groundwater effect on bearing capacity of shallow strip footings." Computers and Geotechnics 139 (November 2021): 104417. http://dx.doi.org/10.1016/j.compgeo.2021.104417.

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28

Tatsuoka, F., C. C. Huang, T. Morimoto, and M. Okahara. "Stress characteristics for shallow footings in cohesionless slopes: Discussion." Canadian Geotechnical Journal 26, no. 4 (November 1, 1989): 748–55. http://dx.doi.org/10.1139/t89-088.

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29

Graham, J., M. Andrews, and D. H. Shields. "Stress characteristics for shallow footings in cohesionless slopes: Reply." Canadian Geotechnical Journal 26, no. 4 (November 1, 1989): 755–56. http://dx.doi.org/10.1139/t89-089.

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30

Cascone, Ernesto, and Orazio Casablanca. "Static and seismic bearing capacity of shallow strip footings." Soil Dynamics and Earthquake Engineering 84 (May 2016): 204–23. http://dx.doi.org/10.1016/j.soildyn.2016.02.010.

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31

Benmebarek, Sadok, Insaf Saifi, and Naima Benmebarek. "Undrained Vertical Bearing Capacity Factors for Ring Shallow Footings." Geotechnical and Geological Engineering 35, no. 1 (October 24, 2016): 355–64. http://dx.doi.org/10.1007/s10706-016-0110-y.

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32

El Wakil, Amr Z. "Horizontal capacity of skirted circular shallow footings on sand." Alexandria Engineering Journal 49, no. 4 (December 2010): 379–85. http://dx.doi.org/10.1016/j.aej.2010.07.003.

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33

Budhu, Muniram. "Corrigendum: Design of shallow footings on heavily overconsolidated clays." Canadian Geotechnical Journal 49, no. 6 (June 2012): 753. http://dx.doi.org/10.1139/t2012-044.

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34

Azeddine, Bendaas, and Merdas Abdelghani. "The cavity’s effect on the bearing capacity of a shallow footing in reinforced slope sand." Soils and Rocks 46, no. 1 (January 11, 2023): e2023003622. http://dx.doi.org/10.28927/sr.2023.003622.

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This paper presents an experimental and numerical study for the effect of the cavity on the behaviour of a strip footing positioned on a reinforced sand slope. This study used a new type of geosynthetics called fiber carbon and fiber glass. These components have the potential to isolate the soil inside the geosynthetic and prevent shears stress mobilization. The investigation aimed to determine the effect of cavity depth (h) and the number of reinforcing layers (N) on the bearing capacity and settlement characteristics of footing, empirically for investigating the effect of cavity on the bearing capacity, some parameters were assumed constant in all tests, for example, relative density, a distance of the footing from the slope edge, and length between layers of reinforcement. The variable parameters are the distance between footings and centre of cavity and the number of reinforcing layers. The results show that the settlement behaviour of footing adjacent to a soil slope is significantly affected by h and N. It is observed that qu, which represents the ultimate bearing capacity, improves with an increase in N. The influence of the cavity appeared insignificant when it was positioned at a depth equal to twice the width of footing.

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35

Thomé, Antônio, Maciel Donato, Nilo Cesar Consoli, and James Graham. "Circular footings on a cemented layer above weak foundation soil." Canadian Geotechnical Journal 42, no. 6 (December 1, 2005): 1569–84. http://dx.doi.org/10.1139/t05-069.

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This work proposes a method for predicting the behavior of shallow footings bearing on an upper layer of processed cemented soil that overlies a lower layer of weakly bonded residual soil with a high void ratio. The paper describes the results of a series of field plate tests and numerical simulations. The results lead to a semi-empirical method for designing shallow foundations on a double-layer system. The method has been validated by comparison of predicted values with results from a separate series of plate-loading tests. For engineering practice, the proposed method provides acceptable predictions of bearing capacities and loadsettlement curves.Key words: footings, cemented layer, layered system, weakly bonded, high void ratio.

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36

Kumar, Rahul, Pijush Samui, Sunita Kumari, and Yildirim Hüseyin Dalkilic. "Reliability Analysis of Circular Footing by Using GP and MPMR." International Journal of Applied Metaheuristic Computing 12, no. 1 (January 2021): 1–19. http://dx.doi.org/10.4018/ijamc.2021010101.

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Circular footings are designed to bear a load of super structures. Studies have been done on the influence of soil properties on bearing capacity of shallow foundations. The use of circular foundation is practical in geotechnical engineering. During the design of circular footing, bearing capacity of soil is taken into consideration, and cohesion (c), unit weight (γ), and angle of internal friction (ϕ) are the most variable parameters. Reliability analysis is used frequently for the design of circular footing. Most of the authors have used first order second moment methods (FOSM). However, FOSM is a time-consuming method. Drawbacks of FOSM have been overcome by genetic programming (GP), minimax probability machine regression (MPMR). This article gives a distinct analysis between the developed MPMR based FOSM and GP-based FOSM.

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37

Hakhamaneshi, Manouchehr, Bruce L. Kutter, Andreas G. Gavras, Sivapalan Gajan, Angelos Tsatsis, Weian Liu, Keshab Sharma, et al. "Database of rocking shallow foundation performance: Slow-cyclic and monotonic loading." Earthquake Spectra 36, no. 3 (March 16, 2020): 1585–606. http://dx.doi.org/10.1177/8755293020906564.

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Many physical model tests have examined the performance of rocking foundations during cyclic and seismic loading. These tests varied in model size, testing equipment, superstructure properties, footing shape, supporting soil environment, and loading protocol. “FoRCy, Foundation Rocking database of Cyclic and Monotonic Loading” is a new database (published at https://datacenterhub.org/ ), summarizing the results of monotonic and slow-cyclic loading tests of rocking foundations. The database consists of columns identifying testing equipment and facility, soil, superstructure, and system properties, as well as loading protocol and results. The database contains 456 records (rows), each one being unique in either model configuration or loading amplitude. To illustrate its value, this article shows correlations between (1) settlement, rotation, and factor of safety with respect to bearing capacity and (2) moment and cumulative rotation for shallow footings. Data indicate that the rotation required to mobilize the moment capacity is surprisingly constant (about 0.01 radians) for a wide range of experiments.

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38

SOUBRA, A. H. "SEISMIC BEARING CAPACITY OF SHALLOW STRIP FOOTINGS IN SEISMIC CONDITIONS." Proceedings of the Institution of Civil Engineers - Geotechnical Engineering 125, no. 4 (October 1997): 230–41. http://dx.doi.org/10.1680/igeng.1997.29659.

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39

OKAMURA, Mitsu, Jiro TAKEMURA, and Tsutomu KIMURA. "A study on bearing capacities of shallow footings on sand." Doboku Gakkai Ronbunshu, no. 463 (1993): 85–94. http://dx.doi.org/10.2208/jscej.1993.463_85.

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40

Choudhury, Deepankar, and K. S. Subba Rao. "Seismic Bearing Capacity of Shallow Strip Footings Embedded in Slope." International Journal of Geomechanics 6, no. 3 (May 2006): 176–84. http://dx.doi.org/10.1061/(asce)1532-3641(2006)6:3(176).

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41

Kusakabe, Osamu, Yoshito Maeda, and Masatoshi Ohuchi. "Large‐Scale Loading Tests of Shallow Footings in Pneumatic Caisson." Journal of Geotechnical Engineering 118, no. 11 (November 1992): 1681–95. http://dx.doi.org/10.1061/(asce)0733-9410(1992)118:11(1681).

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42

Kholdebarin, Alireza, Ali Massumi, and Mohammad Davoodi. "Seismic bearing capacity of shallow footings on cement-improved soils." Earthquakes and Structures 10, no. 1 (January 25, 2016): 179–90. http://dx.doi.org/10.12989/eas.2016.10.1.179.

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43

Ziccarelli, Maurizio, and Marco Rosone. "Influence of a Thin Horizontal Weak Layer on the Mechanical Behaviour of Shallow Foundations Resting on Sand." Geosciences 11, no. 9 (September 16, 2021): 392. http://dx.doi.org/10.3390/geosciences11090392.

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The presence of minor details of the ground, including soil or rock masses, occurs more frequently than what is normally believed. Thin weak layers, shear bands, and slickensided surfaces can substantially affect the behaviour of foundations, as well as that of other geostructures. In fact, they can affect the failure mechanisms, the ultimate bearing capacity of footings, and the safety factor of the geotechnical system. In this research, numerically conducted through Finite Element Code Plaxis 2D, the influence of a horizontal thin weak layer on the mechanical behaviour of shallow footings was evaluated. The obtained results prove that the weak layer strongly influences both the failure mechanism and the ultimate bearing capacity if its depth is lower than two to four times the footing width. In fact, under these circumstances, the failure mechanisms are always mixtilinear in shape because the shear strains largely develop on the weak layer. However, the reduction in the ultimate bearing capacity is a function of the difference between the shear strength of the foundation soil and the layer. The presence of a thin weak layer decreases the ultimate bearing capacity up to 90%. In conclusion, this research suggests that particular attention must be paid during detailed ground investigations to find thin weak layers. Based on the obtained results, it is convenient to increase the soil volume investigation to a depth equal to four times the width of the foundation.

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44

Kutter, Bruce L., Mark Moore, Manouchehr Hakhamaneshi, and Casey Champion. "Rationale for Shallow Foundation Rocking Provisions in ASCE 41-13." Earthquake Spectra 32, no. 2 (May 2016): 1097–119. http://dx.doi.org/10.1193/121914eqs215m.

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ASCE 41-13 supports three methods of modeling the soil-structure interaction for rocking footings as components of a foundation-building system: Method 1 uses uncoupled moment, shear, and axial springs; Method 2 uses a nonlinear gapping bed of springs; and Method 3 is used for structural footings that are flexible relative to the underlying soil. New component action tables in ASCE 41-13 provide modeling parameters and acceptance criteria for nonlinear and linear analysis of shallow foundation components. The values in the component action tables for nonlinear procedures were largely based upon analysis of foundation performance in model tests on rocking foundations. The primary measure to assess foundation performance is residual settlement or uplift. The acceptance criteria for linear analysis procedures ( m-factors) were derived from the allowable rotations for nonlinear procedures. A design example is presented in an online Appendix to illustrate differences between the current and previous versions of ASCE 41 and ASCE 31.

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45

Taylor, Adam G., and Jae H. Chung. "Explanation and Application of the Evolving Contact Traction Fields in Shallow Foundation Systems." Geotechnics 2, no. 1 (January 14, 2022): 91–113. http://dx.doi.org/10.3390/geotechnics2010004.

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The present paper provides a qualitative discussion of the evolution of contact traction fields beneath rigid shallow foundations resting on granular materials. A phenomenological similarity is recognized in the measured contact traction fields of rigid footings and at the bases of sandpiles. This observation leads to the hypothesis that the stress distributions are brought about by the same physical phenomena, namely the development of arching effects through force chains and mobilized intergranular friction. A set of semi-empirical equations are suggested for the normal and tangential components of this contact traction based on past experimental measurements and phenomenological assumptions of frictional behaviors at the foundation system scale. These equations are then applied to the prescribed boundary conditions for the analysis of the settlement, resistance, and stress fields in supporting granular materials beneath the footing. A parametric sensitivity study is performed on the proposed modelling method, highlighting solutions to the boundary-value problems in an isotropic, homogeneous elastic half-space.

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46

Jo, Myoung Su, Ki Tae Lee, Ho Deok Kang, Hong Bum Cho, and Tien Dung Nguyen. "Point Foundation (PF) method: Principles and recent research findings." Journal of Science and Technology in Civil Engineering (STCE) - NUCE 14, no. 3 (August 19, 2020): 53–66. http://dx.doi.org/10.31814/stce.nuce2020-14(3)-05.

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Conventionally, cement deep mixing (CDM) columns are designed to have constant diameters over the improved depth as this facilitates the construction procedures. However, this design pattern may be inefficient in cases of spread footings or shallow foundations. This paper first briefly introduces principles, construction procedures and quality control techniques of an innovative CDM method that can create head-enlarged column, named as Point Foundation (PF). The method is practically implemented with a specific binder that is environment-friendly and more effective in strength enhancing compared with the common binder as cement. Static load tests on three instrumented PF columns indicate that the variation trend of induced vertical stress profile along the columns in general is similar to that under the centre of shallow footings on elastic soil medium. However, the stress profile in the (semi-rigid) PF columns is larger than that in elastic soil but less than that in (rigid) PHC pile. This confirms the load transfer mechanism along semi-rigid columns like CDM/PF. Test results also indicate that at the depth of one to two times head diameters the induced stress remains just 20% the applied pressure. Findings on the trend of the induced vertical stress in the columns suggests that the settlement of common shallow footings on CDM/PF column-reinforced grounds should be evaluated using 3D condition taking into account the fact that the induced stress decreases with depth. Keywords: ground improvement; Point Foundation (PF); tapered cross section; load transfer mechanism; load-settlement behavior.

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47

Marandi, S. M., and H. Javdanian. "Laboratory Studies on Bearing Capacity of Strip Interfering Shallow Foundations Supported by Geogrid-Reinforced Sand." Advanced Materials Research 472-475 (February 2012): 1856–69. http://dx.doi.org/10.4028/www.scientific.net/amr.472-475.1856.

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Abstract: In recent years, geosynthetics are used and considered by many scientists for various earth structures. This is due to their good performance and ease of execution. Many researchers carried out extensive studies on the behavior properties of geosynthetics. However, much attention has not been given to detailed studies and investigation on bearing capacity of interfering shallow-foundations supported by geogrid reinforced sand. In this research, a series of experimental tests was carried out on the effects of geometrical parameters on bearing capacity of interfering shallow foundations supported by geogrid reinforced sand. A numerical model and design charts were introduced to predict bearing capacity. The results showed that the bearing capacity increased using geogrid reinforcement and a good correlation exists between the model and the conventional theoretical relations. Also, the main parameters affecting on the values of the interference factor were the footing distance (s/B) and the number of reinforcement layers (N). However, the suggested interference factor model had an effective reflection on the calculated bearing capacities of the footings.

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48

Adarsh, S., R. Dhanya, G. Krishna, R. Merlin, and J. Tina. "Prediction of Ultimate Bearing Capacity of Cohesionless Soils Using Soft Computing Techniques." ISRN Artificial Intelligence 2012 (December 5, 2012): 1–10. http://dx.doi.org/10.5402/2012/628496.

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This study examines the potential of two soft computing techniques, namely, support vector machines (SVMs) and genetic programming (GP), to predict ultimate bearing capacity of cohesionless soils beneath shallow foundations. The width of footing (), depth of footing (), the length-to-width ratio () of footings, density of soil ( or ), angle of internal friction (), and so forth were used as model input parameters to predict ultimate bearing capacity (). The results of present models were compared with those obtained by three theoretical approaches, artificial neural networks (ANNs), and fuzzy inference system (FIS) reported in the literature. The statistical evaluation of results shows that the presently applied paradigms are better than the theoretical approaches and are competing well with the other soft computing techniques. The performance evaluation of GP model results based on multiple error criteria confirms that GP is very efficient in accurate prediction of ultimate bearing capacity cohesionless soils when compared with other models considered in this study.

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49

Butterfield, R., and G. Gottardi. "A complete three-dimensional failure envelope for shallow footings on sand." Géotechnique 44, no. 1 (March 1994): 181–84. http://dx.doi.org/10.1680/geot.1994.44.1.181.

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50

Maheshwari, Priti. "Settlement of shallow footings on layered soil: state-of-the-art." International Journal of Geotechnical Engineering 9, no. 1 (December 24, 2014): 42–48. http://dx.doi.org/10.1179/1939787914y.0000000065.

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