青岛复合地层双洞隧道开挖变形规律

DEFORMATION LAW OF DOUBLE-HOLE TUNNEL EXCAVATION IN QINGDAO COMPOSITE STRATUM

双线隧道开挖不同于单线隧道,为研究复合地层地铁双洞隧道开挖施工引起的地表沉降规律,文中基于青岛地铁四号线静沙区间的相关数据,通过数值模拟对双洞隧道上覆土层的不同组合施工沉降变形规律进行研究。分析结果表明,隧道上覆土层中砂土与黏土层厚度的变化,对双线隧道开挖地表沉降最大值、地表沉降和围岩的应力状态的影响较小,变化幅度也影响较小,即不同的上覆土层条件下,对双线隧道开挖地表沉降规律的影响相对较小。

The excavation of double-line tunnel is different from that of single-line tunnel.The relevant data of the static sand area of Qingdao Metro Line 4 is taken to study the law of surface settlement caused by the excavation of double-hole tunnel in composite stratum.The settlement deformation law of different combinations of overlying soil layers of double-hole tunnel is studied by numerical simulation.The analysis results show that the change of the thickness of sand and clay layer in the overlying soil layer of the tunnel has little influence on the maximum surface settlement,surface settlement and the stress state of the surrounding rock of the double-track tunnel excavation with the small change range,that is,the influence on the surface settlement law of the double-track tunnel excavation is relatively small under different overlying soil conditions.