The short-term surface settlements in double-line tunnel construction were studied. The tunnels were ex-cavated with double lines by mining method and with 13. 2m distance from center to center. They were excavated symmetrically with V-class surrounding rock. The settlement predictions were performed with finite element method by using FLAC3D, which can simulate the excavation, ground support and face support of the tunnels. The predic-tions were performed on a typical geological zone, which was considered to be critical in terms of surface settle-ment. Through the simulation of construction process, in which the two tunnels were excavated symmetrically with subsurface excavation, the surface settlement in construction was obtained. The settlement could be divided into two stages, and the settlement in the first stage was greater than that of the second stage. Ultimately the safe and feasi-ble method was provided for metro tunnel construction in the dense regions of buildings.%研究了左右双线矿山法隧道施工时的短期地面沉降。采用矿山法进行双线掘进,两隧道中心距13．2m,V级围岩CRD法进行施工,两侧隧道断面对称开挖。使用FLAC3D进行沉降分析,该软件能模拟地下隧道的掘进、支护和掌子面支护等。针对某地地质特征进行预测,这些特征是决定地面沉降量的关键因素。通过模拟左右双隧道对称掘进施工的暗挖隧道施工过程,得到了施工时的地面沉降规律,即沉降可分为两个阶段,且第一阶段沉降大于第二阶段沉降。最终为在市内建筑物密集区域修建地铁隧道提供安全可行的方法。
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