scholarly journals A framework to predict the load-settlement behavior of shallow foundations in a range of soils from silty clays to sands using CPT records

2021 ◽  
Author(s):  
Hossein MolaAbasi ◽  
Aghileh Khajeh ◽  
Reza Jamshidi Chenari ◽  
Meghdad Payan
Keyword(s):  
Shallow Foundations ◽  
Settlement Behavior

scholarly journals A Framework to Predict the Load-Settlement Behavior of Shallow Foundations in a Range of Soils from Silty Clays to Sands using CPT Records

2021 ◽  
Author(s):  
Hossein MolaAbasi ◽  
Aghileh Khajeh ◽  
REZA JAMSHIDI CHENARI ◽  
Meghdad Payan
Keyword(s):  
Bearing Capacity ◽  
Volterra Series ◽  
Current Model ◽  
Shallow Foundations ◽  
Hyperbolic Function ◽  
Cone Penetration ◽  
Settlement Behavior ◽  
Tip Resistance ◽  
Allowable Bearing Capacity ◽  
Load Tests

Abstract Using a set of cone penetration test (CPT) records,the current paper develops a general framework based on regression analyses to model the load-settlement (q-s) behavior of shallow foundations resting on a variety of soils ranging from silty clays to sands.A three-parameter hyperbolic function is employed to rigorously examine the obtainedq-s curves, and to determine the model parameters.Also, the results of someCPT soundings, including the corrected cone tip resistance (qt) and the skin friction (Rf),are adopted to predict the results of plate load tests(PLT). The findingscorroborate the high accuracy of the proposed model, thereasonable performance of the hyperbolic function and the use of the Volterra series to predict the q-s curves.Moreover, the obtained curves from the newly developed model arecompared to those from other methods in the literature which cross-confirms the efficacyof the current model. Asensitivity analysis isalso conductedand the exclusive effects of all the contributing parameters are assessed among which Rfis shown to be the most influential. Ultimately, simple solutionsare adoptedto determine variouskey geotechnical parameters, like the ultimate bearing capacity (qult), the allowable bearing capacity (qa) andthe modulus of subgrade reaction (ks).

scholarly journals Influence of Poisson’s Ratio on the Stress vs. Settlement Behavior of Shallow Foundations in Unsaturated Fine-Grained Soils

2016 ◽  
pp. 71-79
Author(s):  
Won Taek Oh ◽  
Sai K. Vanapalli
Keyword(s):  
Poisson’S Ratio ◽  
Unsaturated Soils ◽  
Shallow Foundations ◽  
Poisson's Ratio ◽  
Degree Of Saturation ◽  
Elastic Continuum ◽  
Fine Grained ◽  
Linear Elastic ◽  
Settlement Behavior ◽  
The Relationship

Poisson’s ratio is typically assumed to be constant for both saturated and unsaturated soils. However, the back-calculated Poisson’s ratio using the relationship between elastic and shear modulus (i.e. the equation for homogeneous, isotropic and linear elastic continuum) published in the literature showed that the Poisson’s ratio is not constant but decreases with the degree of saturation (or increasing suction). In the present study, more focused investigations are undertaken to study the influence of Poisson’s ratio on the stress vs. settlement (SVS) behaviour of shallow foundations in an unsaturated fine-grained (UFG) soil. The FEA are carried out using the software, SIGMA/W (GeoStudio 2007) to better understand the SVS behavior taking account of the influence of Poisson’s ratio for different matric suction values and compared with the model footing tests conducted in an UFG soil. Several suggestions are made with respect to the influence of Poisson’s ratio on the SVS behavior of shallow foundations in the UFG soils based on the results of this study.

Effect of dissolution on the load–settlement behavior of shallow foundations

2016 ◽  
Vol 53 (8) ◽  
pp. 1353-1357 ◽  
Author(s):  
Minsu Cha ◽  
J. Carlos Santamarina
Keyword(s):  
Liquid Phase ◽  
Discrete Element Method ◽  
Shallow Foundations ◽  
Mineral Dissolution ◽  
Shallow Foundation ◽  
Force Chains ◽  
Small Scale ◽  
Settlement Behavior ◽  
Medium Porosity ◽  
Solid Liquid

Mineral dissolution and solid–liquid phase change may cause settlement or affect the bearing capacity of shallow foundations. The effect of gradual grain dissolution on small-scale shallow foundation behavior is investigated using the discrete element method. Results show that dissolution is most detrimental during early stages, as initially contacting particles shrink and force chains must reform throughout the medium. Porosity tends to increase during dissolution and force chains evolve into strong localized forces with a honeycomb topology. Higher settlements are required to mobilize bearing resistance in post-dissolution sediments than in pre-dissolution ones. Subsurface mineral dissolution beneath a footing under load is the worst condition; in fact, settlements in such cases are higher than when a foundation load is applied on a sediment that has already experienced dissolution.

scholarly journals Settlement Behavior of Shallow Foundations in Unsaturated Soils under Rainfall

2017 ◽  
Vol 9 (8) ◽  
pp. 1417 ◽  
Author(s):  
Yongmin Kim ◽  
Hyundo Park ◽  
Sangseom Jeong
Keyword(s):  
Unsaturated Soils ◽  
Shallow Foundations ◽  
Settlement Behavior

Behavior of eccentrically loaded shallow foundations resting on composite soils

2019 ◽  
Vol 23 ◽  
pp. 220-230 ◽  
Author(s):  
Abbasali TaghaviGhalesari ◽  
Mohammadreza Khaleghnejad Tabari ◽  
Asskar Janalizadeh Choobbasti ◽  
Nima EsmaeilpourShirvani
Keyword(s):  
Shallow Foundations

scholarly journals Mechanisms beneath rectangular shallow foundations on sands: vertical loading

Géotechnique ◽  
2020 ◽  
Vol 70 (12) ◽  
pp. 1083-1093
Author(s):  
Yining Teng ◽  
Sam A. Stanier ◽  
Susan M. Gourvenec
Keyword(s):  
Shallow Foundations ◽  
Vertical Loading

Comparison of the Bidirectional Load Test with the Top-Down Load Test

2005 ◽  
Vol 1936 (1) ◽  
pp. 108-116 ◽  
Author(s):  
Oh Sung Kwon ◽  
Yongkyu Choi ◽  
Ohkyun Kwon ◽  
Myoung Mo Kim
Keyword(s):  
Load Transfer ◽  
Measurement Data ◽  
Load Test ◽  
Load Testing ◽  
Pile Head ◽  
Top Down ◽  
Simple Method ◽  
Testing Method ◽  
Settlement Behavior ◽  
Cell Test

For the past decade, the Osterberg testing method (O-cell test) has been proved advantageous over the conventional pile load testing method in many aspects. However, because the O-cell test uses a loading mechanism entirely different from that of the conventional pile loading testing method, many investigators and practicing engineers have been concerned that the O-cell test would give inaccurate results, especially about the pile head settlement behavior. Therefore, a bidirectional load test using the Osterberg method and the conventional top-down load test were executed on 1.5-m diameter cast-in-place concrete piles at the same time and site. Strain gauges were placed on the piles. The two tests gave similar load transfer curves at various depth of piles. However, the top-down equivalent curve constructed from the bidirectional load test results predicted the pile head settlement under the pile design load to be approximately one half of that predicted by the conventional top-down load test. To improve the prediction accuracy of the top-down equivalent curve, a simple method that accounts for the pile compression was proposed. It was also shown that the strain gauge measurement data from the bidirectional load test could reproduce almost the same top-down curve.

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