Iterative load transfer procedure for settlement evaluation of lattice-shaped diaphragm walls in multilayered soil

Abstract Lattice-shaped diaphragm wall (LSDW) is an emerging bridge foundation system that offers high stiffness, construction efficiency, low cost and minimal noise. However, the scarce knowledge on settlement prediction of LSDW has hindered its application in practice. This study proposes an approach to predict the settlement of LSDW in multilayered soils based on the load transfer approach. A simplified analytical approach and related load transfer models are proposed to analyze the load transfer mechanism of an LSDW. Specific load transfer models and parameters of external skin friction and wall base resistance for the LSDW are discussed in detail. Special attention is given to the derivation of models for soil core internal skin friction and base resistance. An iterative solution procedure with three appropriate displacement criteria is then proposed for the load transfer analysis of LSDW. A full scale field test and relevant numerical study were conducted on a single chamber LSDW foundation to evaluate the load transfer mechanism of LSDW. In addition, a published full scale study and numerical analysis involving multi chamber LSDW were investigated to validate the predictions of the proposed approach. Reasonable agreement between the calculated, measured and simulated load-settlement responses is observed. In general, the results validated the adopted models for the external and internal skin friction and base resistance and the corresponding models parameters. The results provide useful guidance for design of LSDW in terms of contribution of soil core skin friction to the load carrying capacity.