Behavior of stepped soil-nail wall

Stepped soil-nail wall is formed by setting a platform in the middle part of a typical soil-nail wall. Due to the presence of the platform, the earth pressure distribution of the stepped soil-nail wall is changed, and the stress state and strain of soil are also changed. Compared with those of the typical soil-nail wall, the deformation and soil-nail internal force of the sepped soil-nail wall are smaller, and the stability is higher. Both the position and width of the platform influence the behavior of the stepped soil-nail wall. According to the numerical calculation and engineering experience, for homogenous soil slopes, the position of platform is suggested to be placed at a depth whick is 0.6 times the foundation pit. For the slope with weak interlayer, the flatform is suggested to be set on the top surface of the weak interlayer. The step width is suggested to be not less than 0.1 times the depth of foundation pit. Through a practical engineering example, the general behaviour of both the typical soil-nail wall and the stepped soil-nail are compared. It is demonstrated that both the horizontal displacement and the nail force of the stepped soil-nail wall are smaller than those of the typical soil-nail wall, and the stability of the former is higher.