Effect and Mechanism of Subsoil Fertilization on the Albic Luvisol Improvement;

Based on the bad stability property in the soft rock of two-way mountain tunnel in loess area and by means of the three-dimensional finite element method,the effect of the length of step and the length and the width of core soil on the longitudinal displacement of tunnel face,the plastic zone depth behind tunnel face and tunnel plastic area are analyzed.

This paper probes into the ringlike drift heading method for multidrop tunnels with preformed core soil, introduces the construction flow sheet, the construction methods and construction control key points, and puts forward some measures for the quality and safety of the construction.

Effect of Subsoil-fertilizing of Lessive Soil;