ABSTRACT
The span between shield tunnel and the three sections of blasting tunnel is quite near, respectively 4.425 m, 3.14 m, 0.775 m. The cross section of the blasting tunnel is relatively large, with the average span over 10m, and the maximum over 14m. And the depth of this tunnel is relatively shallow. All these give rise to risks in construction. The soil compositions of the proposed construction site are mainly plain fill, loess soil, silty clay, silt, fine sand, medium sand and coarse sand. The inner part of tunnel is mainly composed of coarse sand and medium sand.
