Mechanical mechanism of new metro tunnel passing under existing metro tunnel
1. School of Civil Engineering, Shandong University, Jinan, Shandong 250061, China; 2. Institute of Marine Science and Technology, Shandong University, Qingdao, Shandong 266237, China
Abstract：For the new metro tunnel passing under the existing metro tunnel, based on the three-dimensional numerical analysis method, the field monitoring data was compared to verify the simulation reliability. The effects of three tunnel construction schemes of entire section method, benching tunneling construction method and shield method on existing metro structures were investigated, and the effective deformation control measures were proposed. The results show that compared with the entire section method and the benching tunneling construction method, the shield method can effectively reduce the earth surface and existing metro tunnel settlements and the principal stress of existing tunnel structure, and the convergence time of settlement is shorter than those of other two schemes. Through effective grouting reinforcement measures, the surface subsidence, the uneven settlement of existing metro tunnel and the settlement of natural rock formations can be drastically reduced. In the process of construction, the reasonable selection of grouting reinforcement area should be combined with the actual situation to avoid material waste.
2018, Vol. 39 
