Abstract
Due to the complex construction conditions of shield tunnels, ground disturbance is inevitable during the construction process, which leads to surface settlement and, in serious cases, damage to surrounding buildings (structures). Therefore, it is especially important to effectively control the constructive settlement of subway tunnels when crossing settlement-sensitive areas such as high-density shantytowns. Based on the project of Wuhan Metro Line 8 Phase I, the shield of Huangpu Road Station-Xujiapang Road Station interval crossing high-density shantytowns, we study the disturbance control technology of oversized diameter mud and water shield crossing unreinforced settlement-sensitive areas during the construction process. By optimizing the excavation parameters and evaluating the ground buildings, the excavation process can be monitored at the same time, and the water pressure, speed, and tool torque required during the excavation during the construction process can be finely adjusted; the control of tunneling process parameters can provide reference and basis for analyzing the construction control of large-diameter shield through old shantytowns.
Highlights
With the rapid development of urban rail transit construction, complex situations such as mud-water balanced shield crossing complex strata and dense old building complexes are becoming more and more frequent [1,2,3]
After a long investigation on the stability and settlement law of the upper buildings during the shield underpass, it is concluded that in general, the surface settlement of the upper buildings accounts for 30% to 90% of the total amount during the shield underpass
Nassar, and Al-Mahdi [6, 7] studied the problem of surface settlement and deformation; that is, when the actual site water pressure is high, the water storage tunnel encounters soil particles with strong water permeability
Summary
With the rapid development of urban rail transit construction, complex situations such as mud-water balanced shield crossing complex strata and dense old building complexes are becoming more and more frequent [1,2,3]. Erefore, it is necessary to analyze the construction process of post-wall grouting of large-diameter mud and water shield [15]. Li and Yuan [27] used monitoring instruments to measure the dry shrinkage stresses applied to the tube sheet lining, the post-wall grouting tube sheet lining stresses, the tube sheet lining stresses after stabilization of the grouting ring, and the surrounding rock pressure in the shield tunnel during construction. In the centrifugal model test, Meng et al [30] used a mini-shield machine to simulate the shield boring process, including the release of the tube sheet lining from the shield tail, for shield tunnels with different burial depths with or without shield tail voids and derived the deformation of the surrounding strata and the variation of the soil pressure on the top of the tube sheet. Wang et al [5] established a threedimensional finite element model for mud-water balanced shield tunneling, in which the soil was simulated by elastomer, the lining was simulated by shell unit, and the slurry injection was simulated by solid unit, and the support pressure was applied at the excavation surface during shield tunneling, and the slurry injection pressure was considered at the shield tail gap, and the effects of the support pressure and slurry injection pressure on the ground displacement were analyzed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
