A 2D numerical approach to evaluate the distribution of lateral earth pressure behind wall facing in soldier pile wall systems considering arching effects

In a soldier pile wall system, the wall facing (i.e. wall lagging) is used to retain the soil mass between the piles. The key controlling criterion in design of the wall lagging is the maximum bending moment occurring over its span, which is obviously dependent on the magnitude and distribution of lateral earth pressure acting on it. To stay in the conservative side for design purposes, the uniform active lateral earth pressure could be used; however, it is generally agreed in geomechanics that the soil arching phenomenon could reduce significantly the lateral earth pressure acting on the lagging. The current study presents a simple and practical 2D numerical modeling methodology to evaluate the lateral earth pressure distribution and the maximum bending moment in the lagging, taking into account the arching effects. A series of parametric study is performed to examine the effects of various parameters including the soil properties, pile spacing, lagging bending stiffness and the magnitude of lateral earth pressure. The results of the present study show that the lateral earth pressure distribution behind the wall lagging becomes non-uniform due to soil arching. That is, the lateral earth pressure decreases from the maximum at the pile locations to the minimum at the quarter-span of piles and then remains constant until the mid-span of piles. Moreover, the results of the paper show that the obtained distribution of lateral earth pressure compared with the uniform distribution of active pressure reduces significantly the maximum bending moment occurring in the wall lagging. In addition, the results show that the intensity of soil arching depends on the soil friction angle and cohesion as well as the bending stiffness of lagging.

Keywords:

Soldier pile wall systems , Arching effects , Distribution of lateral earth pressure , 2D numerical approach , Maximum bending moment