Fei Xu

Analysis and Design Implications on Stability of Cofferdam Subjected to Water Wave Action

Based on Power-Law nonlinear failure criterion and the upper bound theorem of limit analysis, a numerical solution was developed to analyze the shape of collapsing block and landslide thrust of cofferdam subjected to residual pore pressure which was caused by longstanding water wave action. In the upper bound analysis, the effect of water pressure assumed to be a work rate of external force was considered. To evaluate the validity of the present method, the results were compared with previous findings. The good agreement between the present results and the previous findings indicated that the proposed method was valid to assess the shape of collapsing block and landslide thrust of cofferdam subjected to residual pore pressure. As for the influence of the factors on the shape of collapsing block and landslide thrust, a parametric study was conducted. This parametric study was carried out to optimize the design of cofferdam supporting structures and improve analysis of the stability of cofferdam subjected to water wave action.

Response of a Single Pile Subjected to Tension Load by Using Softening Models

This paper proposes a single exponential model and a double exponential model to simulate the relationship between pile displacement and unit skin friction developed at the pile-soil interface. Based on the proposed two models, two simple analytical approaches were presented for nonlinear analysis of the response of a single tension pile. A highly effective iterative computer program was developed by using the load transfer method. Comparisons of the present computed results, the calculated results derived from other analytical methods, and measured results were made to demonstrate the reliability of the proposed analytical methods.

A simplified approach for settlement analysis of single pile considering pile end settlement induced by skin friction in multilayered soils

A simplified approach for the nonlinear analysis of the load–displacement response of a single pile is presented using the load-transfer approach. In the present method, a hyperbolic model is adopted to simulate the load–displacement response of both the pile base and the shaft. Using the Mindlin displacement solution of the elastic half-space, the pile end settlement induced by the skin friction of pile is calculated. Based on the present analytical method, a highly effective iterative computer program is developed for the analysis of the response of a single pile. The validity of the present method is then demonstrated with the results of the load tests carried on instrumented piles. The calculated results indicate that at all loading levels, the proposed method is generally in good agreement with the well-documented field test results and the calculated results derived from other approaches. It is noted the pile head displacement obtained from the present approach increases with increasing failure ratio of skin friction and end resistance at the same loading level. It is also observed that the influence of the failure ratio of skin friction to the pile head displacement is slightly larger than the influence of the pile end resistance.