scholarly journals Numerical Investigation of the Undrained Compression and Pull-Out Capacity of Suction Foundations in Clay

2015 ◽  
Vol 22 (s1) ◽  
pp. 126-135 ◽  
Author(s):  
Jiaqing Du ◽  
Shouji Du ◽  
Shuilong Shen ◽  
Zhenyu Yin
Keyword(s):  
Bearing Capacity ◽  
Three Dimensional ◽  
Ultimate Bearing Capacity ◽  
Capacity Factor ◽  
Embedment Depth ◽  
Pull Out ◽  
Effective Depth ◽  
Undrained Conditions ◽  
Tresca Criterion ◽  
Bearing Capacity Factor

Abstract This paper presents the results of three-dimensional finite difference analysis of suction foundations in uniform and non-uniform clays under undrained conditions. The Tresca criterion was used to simulate the stress-strain response. The bearing capacity of the foundations was investigated, with the degree of nonhomogeneity (kD/sum) of soil varying from 0 to 5, and the embedment depth being up to four times the foundation diameter. The end bearing capacity factor in compression and the reverse bearing capacity factor in tension were both calculated and were compared with each other under different foundation displacements. Numerical results showed that the ultimate bearing capacity factor can have the same value in cases of both compression and tension. The recommended ultimate bearing capacity factor is determined on the basis of the embedment ratio and displacement magnitude, and the displacement is not more than 30% of the foundation diameter. Finally, two equations are proposed to evaluate both the bearing capacity factor and the effective depth factor.

scholarly journals Determination of bearing capacity of shallow foundations without using superposition approximation

2003 ◽  
Vol 40 (2) ◽  
pp. 450-459 ◽  
Author(s):  
D Y Zhu ◽  
C F Lee ◽  
K T Law
Keyword(s):  
Bearing Capacity ◽  
Field Method ◽  
Ultimate Bearing Capacity ◽  
Shallow Foundation ◽  
Closed Form Expression ◽  
Safe Side ◽  
Superposition Approximation ◽  
Bearing Capacity Factor ◽  
Rigorous Procedure

The Terzaghi superposition assumption has been widely used to determine the bearing capacity of shallow footings. Although this assumption always errs on the safe side, a rigorous procedure to calculate the bearing capacity is still of engineering value. This paper presents such a procedure that is free from errors as a result of the superposition assumption. It demonstrates that the ultimate bearing capacity can be precisely expressed by the Terzaghi equation, except that the bearing capacity factor Nγ is dependent upon the surcharge ratio. A recently developed numerical method, i.e., the critical slip field method, is used to calculate the modification coefficient for modifying Nγ. It is found that this modification coefficient increases with the surcharge ratio at small values of surcharge ratio and then remains constant for large values of surcharge ratio. However, the errors invoked by the superposition assumption do not exceed 10%. On the basis of numerical calculations, a simple closed-form expression of the modification coefficient is proposed that yields the theoretically rigorous ultimate bearing capacity. In the later part of the paper, errors in bearing capacity calculations owing to the use of conventional procedures are analyzed. It is concluded that the continued use of conventional procedures is justified, but the inherent errors should not be neglected in assessing the performance of shallow foundations.Key words: shallow foundation, strip footing, ultimate bearing capacity, critical slip field.

Bearing capacity factor, N γ , for unsaturated soils by ZEL method

2010 ◽  
Vol 5 (3) ◽  
pp. 177-188 ◽  
Author(s):  
M. Jahanandish ◽  
G. Habibagahi ◽  
M. Veiskarami
Keyword(s):  
Bearing Capacity ◽  
Unsaturated Soils ◽  
Capacity Factor ◽  
Bearing Capacity Factor

scholarly journals Computation of Bearing Capacity Factor N-Prandtl's Mechanism

2003 ◽  
Vol 43 (3) ◽  
pp. 1-10 ◽  
Author(s):  
D.M. Dewaikar ◽  
B.G. Mohapatra
Keyword(s):  
Bearing Capacity ◽  
Capacity Factor ◽  
Bearing Capacity Factor

FEA-Based Stability Analysis of Mudmats: Coupled Soil-Structure-Flowline Interaction Model

2013 ◽  
Author(s):  
Basel Abdalla ◽  
F. Steven Wang ◽  
M. Kabir Hossain
Keyword(s):  
Bearing Capacity ◽  
Factor Of Safety ◽  
Interaction Model ◽  
Complex Loading ◽  
Capacity Factor ◽  
Classical Approach ◽  
Soil System ◽  
Sliding Mechanism ◽  
Assessment Approach ◽  
Bearing Capacity Factor

The traditional method of foundation stability assessment for subsea structures is to calculate the bearing capacity factor of safety using classical approach given in the API-RP-2A/2GEO. This classical approach can be overly conservative for foundations under complex loading conditions (e.g., multiple interacting loads). A typical example is pipeline end manifold or flowline sled, which can be subject to self-weight, structure-soil interaction, and multiple interface loads from flowline and jumpers under operational condition. A more rigorous 3D-FEA based assessment approach is developed in this paper to achieve more accurate bearing capacity estimates for a flowline sled supported by mudmat. This fully combined global model comprises the structure (with sliding mechanism), soil foundation, jumpers, and flowline as realistically as possible so as to capture the more accurate interactions among the different parts of whole sled-soil system. The use of such advanced numerical modeling has proven to improve the mudmat bearing capacity factor of safety.

Model Test Research of Surcharge Contribution to Ground Bearing Capacity

2013 ◽  
Vol 353-356 ◽  
pp. 815-818
Author(s):  
Le Yi Chen
Keyword(s):  
Bearing Capacity ◽  
Failure Mode ◽  
Model Test ◽  
Shear Failure ◽  
Theoretical Solution ◽  
Capacity Factor ◽  
Ground Failure ◽  
Capacity Model ◽  
Capacity Calculation ◽  
Bearing Capacity Factor

To investigate the influence of surcharge on bearing capacity, model tests were performed. In the tests, 5 kPa and 10 kPa surcharge was applied on silt respectively. The bearing capacity factor Nq is smaller than theoretical solution, and is only of 60.3% and 80.5% of theoretical solution. Model test show that the ground failure mode is not general shear failure mode in condition of ground under surcharge. In bearing capacity calculation, if bearing capacity factor theoretical solution which is from general shear failure mode is applied, the result will be overestimate.

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