Finite element analysis of cellular circle cofferdam for wet soil

Abstract EN

This paper presented nonlinear finite element analysis to predict the load deflection behavior of circular cell cofferdam under lateral load by using ANSYS (Analysis System) (version 12.1) computer program.

Eight-node solid element (SOLID 45) has been used to model filling soil, and the same element by using overlap and glue technique to model steel sheet pile of cofferdam.

The bond between steel sheet pile and filling soil has been modeled by using nodes merge.

The full Newton-Raphson method is used for the nonlinear solution algorithm.

Single circular cell of width to height ratio b/H (1.00) has been analyzed and their results are compared with experimental data including the following factors: the effect of berm ratio (backfill of cell) (0.4 of the cell height), embedment depth ratios (0.2 and 0.4 of the cell height), Wet subbase soil was used as filling material.

The results obtained using the finite element models represented by the load applied at one third of the cell cofferdam height deflection curves show good agreement (small differences) with the experimental data that based on experimental study done by Al-Kassar, (2011) for the case that considered in this study.The difference between the numerical ultimate loads and the corresponding experimental ultimate loads is in the range between (0-5.56)%.

Only in the case of circular cell cofferdam on ground with width to height ratio b/H=1 the difference was 25%.

For the numerical analysis at used berm ratio of (0.4 of the cell height) has increase the cell resistance (50%), while in experimental study the increase in cell resistance was (33%).

For numerical analysis of using embedment depth ratio of (0.2 of the cell height) the resistance of the cell has increased to (39.02%), compared with the ratio ( 0.4 of the cell height) the cell resistance increased to (53.13%).

While in experimental study when the embedment depth ratio was (0.2 of the cell height) the resistance of the cell increased to (23.8%), compared with the ratio (0.4 of the cell height) the cell resistance increased to (40.72%).