College of Civil and Architecture Engineering,Beijing University of Technology
It is easy to induce complex problems such as excessive deformation of surface and support structure by underground excavation in water-rich sand-sticky composite stratum. Based on a CRD tunnel construction project of Beijing metro line 17, after on-site monitoring of surface settlement, pore water pressure, surrounding rock pressure and internal force of primary branch during construction process, the change law and overall situation of each monitoring object are obtained. The results show that the surface settlement caused by the concealed excavation construction of the new tunnel is large. Although the vault settlement and the convergent deformation rate and the amount of deformation of the pilot tunnel meet the design requirements, the stability value is close to the limit and the surplus is small; the pore water pressure after stabilization is small, about 5kPa, which is basically consistent with the height of geological exploration head; due to the influence of the excavation of the advanced standard line, the surrounding rock pressure of the new tunnel presents the phenomenon of asymmetric distribution from left to right, and the surrounding rock pressure decreases in turn along the tunnel circumference in the order of arch bottom → arch waist → arch foot → arch top → arch shoulder. The distribution of r reinforced stress along the tunnel after stabilization is basically consistent with the surrounding rock pressure, and its maximum value appears at the left arch waist. Based on the above research, the results of this research can provide a certain reference for the design and construction of undercut tunnels in the same type of water-rich sand-viscous composite stratum.
陶连金,董瑞龙,张宇,等. 富水砂-黏复合地层大断面暗挖隧道施工力学行为研究[J]. 科学技术与工程, , ():复制