Assessment of bearing capacity and failure mechanism of single and interfering strip footings on sloping ground

Author(s):  
R. Acharyya ◽  
A. Dey
2019 ◽  
Vol 56 (11) ◽  
pp. 1729-1735 ◽  
Author(s):  
Haizuo Zhou ◽  
Gang Zheng ◽  
Xinyu Yang ◽  
Tao Li ◽  
Pengbo Yang

Assessment of the ultimate bearing capacity of foundations adjacent to slopes is complex as it is highly dependent on the slope geometry and soil properties. Seismic loading may impact both the critical failure mechanism and its associated bearing capacity. The existing approaches for analyzing the seismic bearing capacity of footings near slopes typically employ coefficients developed to fit the conventions of Terzaghi’s bearing capacity equation, herein referred to as the “superposition method.” In this study, a rigorous assessment of the seismic bearing capacity is performed using an upper-bound limit state plasticity framework known as discontinuity layout optimization (DLO), which makes few prior assumptions concerning the failure geometry. Results show that soil properties, slope configuration, and pseudostatic seismic loading all influence the realized failure mechanism and associated bearing capacity. The use of bearing capacity coefficients that fit within the conventional superposition method may underestimate limit loads when the underlying soil provides a relative increase in resistance, but may greatly overestimate bearing capacity when the self-weight of the soil is destabilizing in nature. A set of design charts using direct computational methods for a variety of geometric, geotechnical, and seismic conditions is provided.


2014 ◽  
Vol 580-583 ◽  
pp. 415-419
Author(s):  
Zong Jian Wang ◽  
Liang Lu ◽  
Bin Zheng

Several laboratory model tests were carried out on the bearing capacity of strip footings on reinforced soil foundation and reinforced slope. Compared with unreinforced cases, the deformation and failure of reinforced earth in different foundation conditions were monitored and analyzed. In order to visualize a failure mechanism when the ground reaches the state of limit equilibrium, a new numerical procedure was proposed. Assuming an elastic-perfectly plastic model, a smeared shear band approach and a modified initial stress method enable the proposed procedure to create an explicit collapse mode by the stress yield condition. On the basis of the development of failure mode and deformation of foundation, the bearing capacity of strip footings can be significantly increased by the inclusion of geotextile. And because the procedure considers the stiffness and deformation of the material, it may be applied to complex stability problems.


1974 ◽  
Vol 11 (1) ◽  
pp. 32-45 ◽  
Author(s):  
P. Purushothamaraj ◽  
B. K. Ramiah ◽  
K. N. Venkatakrishna Rao

A method has been formulated for bearing capacity of footings on two layered soils with varying cohesion, friction, and unit weight based on the second theorem of Drucker and Prager (kinematical consideration). The failure mechanism considered was fundamentally similar to that of Prandtl–Terzaghi but with different wedge angles. The critical wedge angles were found in each case. Bearing capacity charts for footings are presented by varying cohesion in layers, with the same friction angle and unit weight. The charts are readily usable for any combination of c2/c1, d/b, φ, and γ.


2021 ◽  
Vol 28 (1) ◽  
pp. 139-152
Author(s):  
Teng Huang ◽  
Dongdong Zhang ◽  
Yaxin Huang ◽  
Chengfei Fan ◽  
Yuan Lin ◽  
...  

Abstract In this study, the flexural bearing capacity and failure mechanism of carbon fiber-reinforced aluminum laminate (CARALL) beams with a double-channel cross-section and a 3/2 laminated configuration were experimentally and numerically studied. Two types of specimens using different carbon fiber layup configurations ([0°/90°/0°]3 and [45°/0°/−45°]3) were fabricated using the pressure molding thermal curing forming process. The double-channel CARALL beams were subjected to static three-point bending tests to determine their failure behaviors in terms of ultimate bearing capacity and failure modes. Owing to the shortcomings of the two-dimensional Hashin failure criterion, the user-defined FORTRAN subroutine VUMAT suitable for the ABAQUS/Explicit solver and an analysis algorithm were established to obtain a progressive damage prediction of the CFRP layer using the three-dimensional Hashin failure criterion. Various failure behaviors and mechanisms of the CARALL beams were numerically analyzed. The results indicated that the numerical simulation was consistent with the experimental results for the ultimate bearing capacity and final failure modes, and the failure process of the double-channel CARALL beams could be revealed. The ultimate failure modes of both types of double-channel CARALL beams were local buckling deformation at the intersection of the upper flange and web near the concentrated loading position, which was mainly caused by the delamination failure among different unidirectional plates, tension and compression failure of the matrix, and shear failure of the fiber layers. The ability of each fiber layer to resist damage decreased in the order of 90° fiber layer > 0° fiber layer > 45° fiber layer. Thus, it is suggested that 90°, 0°, and 45° fiber layers should be stacked for double-channel CARALL beams.


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