三联隧道地表建筑物变形开裂原因分析

THE ANALYSIS OF GROUNDSURFACE BUILDINGS' DEFORMATION AND CRACKING ABOVE SANLIAN TUNNEL

三联隧道中部下穿地表建筑物密集区，埋深90－102m，施工中地表建筑物出现变形开裂。在综合地质勘察工作基础上，结合隧道施工揭示地质情况、地表建筑物变形开裂特征及爆破振速监测资料，分析地表建筑物变形开裂的原因为隧道开挖引起地下水漏失导致土层产生不均匀沉降，地表沟槽中软土受放炮震动产生触变引起地面下沉、开裂，民房建筑质量较差且年久失修，以及施工放炮震动作用等因素所致。后续施工中采用工程措施减少地下水漏失、防止洞内塌方、减小施工放炮震动，实施后效果良好。

The buildings are dense on the groundsurface above middle section of Sanlian Tunnel whose depth is 90-102m, which exhibited deformation and cracking on the tunnel＇s constructing. Uesd by comprehensive geological investigation methods and means, colligated the geological condition presented by tunnel excavation, character of deformation and cracking of groundsurface buildings and the monitoring data of blasting vibrational wave velocity, the reasons for the deformation and cracking of the groundsurface buildings above the tunnel have been analysised as followed, the asymmetry sedimentation in part of soil layers induced by groundwater leaking on tunnel excavation, the ground subsidence and craze by the thixotropy of the soft soil in groundsurface groove produced by blasting vibration, the low quality of mostly local architecture and disrepair for long years, and blasting vibration and so on. Pertinent engineering measures actualized on following construction, which decrease the groundwater leakage, avoid collapse in tunnel and depress blasting vibration, have very well effect for the groundsurface buildings above tunnel.