Soil Arching–Induced Lateral Earth Pressure Redistribution on the Retaining Wall in a Multistrutted Excavation in Soft Soil

Soil arching that is generated and develops within the ground behind the retaining wall in a multistrutted excavation is a soil stress transfer process related to the relative movement between the well-retained soil mass and the inward-moved soil mass. The lateral earth pressure behind the wall is redistributed induced by this soil arching, which has not been deeply investigated. In this paper, the wall deflection, lateral soil movement, ground surface settlement, strut forces, total lateral earth pressure, and the water level outside the excavation were monitored in a multistrutted excavation in soft soil. The measured results indicated that the lateral earth pressure redistribution was associated with the arching effect. A lateral earth pressure model considering the soil arching effect is proposed, and was verified using measurements obtained from this study and the literature. It was found that the coefficients of the proposed model are linearly related to the ratio of the soil volume loss to the gain (RLG), which can be used to characterize the soil arching process development. This study improves the understanding of the lateral earth pressure redistribution induced by soil arching, and the proposed model can be used to calculate more-realistic lateral earth pressure.