Exact probabilistic solution of two-parameter bearing capacity for shallow foundations

1992 ◽  
Vol 29 (5) ◽  
pp. 867-870 ◽  
Author(s):  
Said M. Easa
Keyword(s):  
Bearing Capacity ◽  
Random Variable ◽  
Friction Angle ◽  
Shallow Foundations ◽  
Cohesionless Soil ◽  
Unit Weight ◽  
Previous Solution ◽  
Probabilistic Solution ◽  
Two Parameter ◽  
Soil Unit

An exact probabilistic solution of the ultimate bearing capacity of cohesionless soil for shallow strip foundations is presented. The solution incorporates two random variables: effective friction angle [Formula: see text] and soil unit weight γ. This solution is an extension of a previous solution in which only [Formula: see text] is considered as a random variable. The exact solution is verified using Monte Carlo simulation and the sensitivity of the solution to the coefficient of variation of the soil unit weight is examined. Key words : probability, reliability, bearing capacity, shallow strip foundations, friction angle, soil unit weight.

scholarly journals Prediction of Ultimate Bearing Capacity of Shallow Foundations on Cohesionless Soils: A Gaussian Process Regression Approach

2021 ◽  
Vol 11 (21) ◽  
pp. 10317
Author(s):  
Mahmood Ahmad ◽  
Feezan Ahmad ◽  
Piotr Wróblewski ◽  
Ramez A. Al-Mansob ◽  
Piotr Olczak ◽  
...  
Keyword(s):  
Gaussian Process ◽  
Bearing Capacity ◽  
Gaussian Process Regression ◽  
Ultimate Bearing Capacity ◽  
Shallow Foundations ◽  
Cohesionless Soil ◽  
Unit Weight ◽  
Cohesionless Soils ◽  
Computing Technique ◽  
Theoretical Approaches

This study examines the potential of the soft computing technique—namely, Gaussian process regression (GPR), to predict the ultimate bearing capacity (UBC) of cohesionless soils beneath shallow foundations. The inputs of the model are width of footing (B), depth of footing (D), footing geometry (L/B), unit weight of sand (γ), and internal friction angle (ϕ). The results of the present model were compared with those obtained by two theoretical approaches reported in the literature. The statistical evaluation of results shows that the presently applied paradigm is better than the theoretical approaches and is competing well for the prediction of UBC (qu). This study shows that the developed GPR is a robust model for the qu prediction of shallow foundations on cohesionless soil. Sensitivity analysis was also carried out to determine the effect of each input parameter.

A closed-form probabilistic solution for evaluating the bearing capacity of shallow foundations

1990 ◽  
Vol 27 (4) ◽  
pp. 526-529 ◽  
Author(s):  
C. Cherubini
Keyword(s):  
Bearing Capacity ◽  
Closed Form ◽  
Closed Form Solution ◽  
Friction Angle ◽  
Form Solution ◽  
Shallow Foundations ◽  
Shallow Foundation ◽  
Probabilistic Evaluation ◽  
Allowable Bearing Capacity ◽  
Probabilistic Solution

A closed-form solution for the probabilistic evaluation of shallow foundation bearing capacity according to the model proposed by Terzaghi, as modified by Krizek, is described. A numerical example explains the method of computation. Key words: statistics, probability, ultimate bearing capacity, allowable bearing capacity, shallow foundations, friction angle, numerical methods.

scholarly journals Influence of the groundwater level on the bearing capacity of shallow foundations on the rock mass

2021 ◽  
Author(s):  
Ana Alencar ◽  
Rubén Galindo ◽  
Svetlana Melentijevic
Keyword(s):  
Rock Mass ◽  
Bearing Capacity ◽  
Groundwater Level ◽  
Sensitivity Study ◽  
Shallow Foundations ◽  
Unit Weight ◽  
Geological Strength Index ◽  
Strength Index ◽  
Mass Type

AbstractThe presence of the groundwater level (GWL) at the rock mass may significantly affect the mechanical behavior, and consequently the bearing capacity. The water particularly modifies two aspects that influence the bearing capacity: the submerged unit weight and the overall geotechnical quality of the rock mass, because water circulation tends to clean and open the joints. This paper is a study of the influence groundwater level has on the ultimate bearing capacity of shallow foundations on the rock mass. The calculations were developed using the finite difference method. The numerical results included three possible locations of groundwater level: at the foundation level, at a depth equal to a quarter of the footing width from the foundation level, and inexistent location. The analysis was based on a sensitivity study with four parameters: foundation width, rock mass type (mi), uniaxial compressive strength, and geological strength index. Included in the analysis was the influence of the self-weight of the material on the bearing capacity and the critical depth where the GWL no longer affected the bearing capacity. Finally, a simple approximation of the solution estimated in this study is suggested for practical purposes.

scholarly journals Bearing Capacity of Ring Foundations on Sand Overlying Clay

2020 ◽  
Vol 10 (13) ◽  
pp. 4675
Author(s):  
Chaowei Yang ◽  
Zhiren Zhu ◽  
Yao Xiao
Keyword(s):  
Bearing Capacity ◽  
Friction Angle ◽  
Failure Criteria ◽  
Unit Weight ◽  
Sand Layer ◽  
Collapse Mechanisms ◽  
Internal Radius ◽  
Vertical Bearing ◽  
Vertical Bearing Capacity ◽  
Ring Foundations

The vertical bearing capacity of rough ring foundations resting on a sand layer overlying clay soil is computed in this study by using finite element limit analysis (FELA). The sands and clays are assumed as elastoplastic models, obeying Mohr–Coulomb and Tresca failure criteria, respectively. Based on the FELA results, design charts are provided for evaluating the ultimate bearing capacity of ring foundations, which is related to the undrained shear strength of the clay, the thickness, the internal friction angle, the unit weight of the sand layer, and the ratio of the internal radius to the external radius of the footing. A certain thickness, beyond which the clay layer has a negligible effect on the bearing capacity, is determined. The collapse mechanisms are also examined and discussed.

Modelling the applied vertical stress and settlement relationship of shallow foundations in saturated and unsaturated sands

2011 ◽  
Vol 48 (3) ◽  
pp. 425-438 ◽  
Author(s):  
Won Taek Oh ◽  
Sai K. Vanapalli
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Characteristic Curve ◽  
Friction Angle ◽  
Vertical Stress ◽  
Shallow Foundations ◽  
Surface Settlement ◽  
Soil Parameters ◽  
Finite Element Analyses ◽  
Unsaturated Sands

The bearing capacity and settlement of foundations are determined experimentally or modelled numerically based on conventional soil mechanics for saturated soils. In both methods, bearing capacity and settlement are estimated based on the applied vertical stress versus surface settlement relationship. These methods are also conventionally used for soils that are in an unsaturated condition, ignoring the contribution of matric suction. In this study, a methodology is proposed to estimate the bearing capacity and settlement of shallow foundations in unsaturated sands by predicting the applied vertical stress versus surface settlement relationship. The proposed method requires soil parameters obtained under only saturated conditions (i.e., effective cohesion, effective internal friction angle, and modulus of subgrade reaction from model footing test) along with the soil-water characteristic curve (SWCC). In addition, finite element analyses are undertaken to simulate the applied vertical stress versus surface settlement relationship for unsaturated sands. The proposed method and finite element analyses are performed using an elastic – perfectly plastic model. The predicted bearing capacities and settlements from the proposed method and finite element analyses are compared with published model footing test results. There is good agreement between measured and predicted results.

Study on Vertical Bearing Capacity of the Wide-Shallow Bucket Foundation in Two Layered Sand

2020 ◽  
Author(s):  
Guodong Sun ◽  
Run Liu ◽  
Jijian Lian ◽  
Runbo Cai ◽  
Xu Yang ◽  
...  
Keyword(s):  
Internal Friction ◽  
Bearing Capacity ◽  
Friction Angle ◽  
Internal Friction Angle ◽  
Unit Weight ◽  
Offshore Wind Turbine ◽  
Sand Layer ◽  
Bucket Foundation ◽  
Vertical Bearing ◽  
Vertical Bearing Capacity

Abstract The wide-shallow bucket foundation proposed by Tianjin University of China is a new type of offshore wind turbine foundation. In this paper, the vertical bearing capacity of wide-shallow bucket foundation embedded in two layered sand that contains an underlying medium strength sand layer and a weaker or stronger overlaying sand layer is studied. A parametric study for bearing capacity is carried out with the ratio of unit weight γ1/γ2 (where γ1 and γ2 are the unit weight of the upper and lower sand layers respectively), the ratio of internal friction angle φ1/φ2 (where φ1 and φ2 are the internal friction angle of the upper and lower sand layers respectively) and relative thickness of the top sand layer H1/B (where H1 and B are the thickness of the top sand layer and the bucket foundation diameter). All of the presents were performed by the Finite Element Method and the results show that the thickness of the top layer has a great influence on the vertical bearing capacity of the foundation. Specifically, the upper sand layer is stronger, the bearing capacity ascends with the increase of the thickness of the top layer, and on the contrary, the upper layer is weaker, and the bearing capacity decreases with the increase of the top layer thickness. In addition, the bearing capacity of the foundation also increases with the ratios of the effective unit weight and the internal friction angle.

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