Research on Construction Technology of Tunnel Face Slump in Soft Rock Tunnel of China-Laos Railway

Abstract

 In Taos barrow of jade grinding rail tunnel engineering ii, of rich water karst region slipped in weak rock tunnel collapse mechanism and treatment technology for research, slipped through the establishment of the tunnel surrounding rock collapse mechanics analysis model, the theoretical calculation and finite element calculation software simulation method of combining the, constraints of the tunnel to slip down position at the beginning of surrounding rock and the structural stability analysis, According to the analysis results, the corresponding treatment measures are put forward. The results show that the settlement value of surrounding rock vault is 84.7mm, and the horizontal convergence value of arch waist is 167.4mm. The deformation value of surrounding rock is large, and it is easy to collapse. The plastic zone of surrounding rock mainly occurs at the junction of upper and lower steps on the face of the face, and the maximum plastic strain is 6.63×10^-2. The arch waist of the primary support structure is prone to stress concentration, which should be reinforced during construction to prevent instability failure. According to the actual situation of tunnel construction site, combined with the finite element calculation results, the treatment structure of concrete filling combined with small pipe reinforcement was used to treat the tunnel slide collapse section. The treatment effect of tunnel slide collapse section was better, which provided a reference for the treatment of the same situation in the subsequent construction section.