Bearing capacity analysis of multi-layered coral sand foundation based on the upper-bound multi-rigid-block approach

In order to study the bearing capacity of layered coral sand foundations,a multi-block failure mechanism suitable for layered sandy soil was constructed based on the upper bound theory of limit analysis. Formulas for calculating the external work rates and internal energy dissipation rates were established. By introducing a sequential quadratic programming optimization algorithm,an upper limit analysis method for evaluating the ultimate bearing capacity of layered coral sand foundations was established. The established method was validated by comparisons with existing research results. The established failure mechanism overcomes the limitation of the existing layered soil failure mechanism,which requires the lower layer to be clay. The results indicate that when the failure mechanism traverses different layered formations,the calculated foundation bearing capacity and critical failure mechanism based on the layered foundation model differ significantly from those based on the homogeneous foundation model,which shows that it is significant to consider the diverse stratigraphic properties. Compared with foundation load tests,the adopted upper bound analysis method,by adjusting various parameters of different layers of soil,can rapidly obtain the upper limit solution of foundation bearing capacity,providing reference for the design of coral sand foundation. © 2024 Southeast University. All rights reserved.