Lateral Seismic Soil Pressures on Soldier Pile Walls

This paper presents a simplified procedure for computing lateral seismic earth pressures on soldier pile retaining walls. This approach is to develop two curves of lateral load versus displacement behavior to consider the soil-pile-wall interaction in a "decoupled" way. A curve of lateral earth driving force versus displacement is first established by slope stability analysis for the sliding soil mass behind the wall based on the Newmark chart that relates the standardized maximum displacement of the soil mass to the limiting acceleration coefficient. A second curve of lateral load versus displacement for the soldier pile/wall is then obtained by lateral analysis of the pile/wall structure under the lateral earth driving force. The intersection between the two load-displacement curves is considered as the lateral earth driving force on the pile/wall. An example of analyzing one soldier pile retaining wall is presented in this paper to illustrate the proposed method. The simplified method of accounting for the soil-pile-wall interaction may be used to estimate the lateral soil seismic driving forces on piles/walls without the uncertainty in determining the seismic coefficient related to the use of the Mononobe-Okabe method and choosing the design wall displacement. However, the simplified method is not validated and the results from the method should be verified against finite element studies or field or model testing.