浅埋大跨隧道下穿建筑物的安全影响研究

STUDY OF BUILDING SAFETY DURING SHALLOW-BURIED LARGE-SPAN TUNNEL UNDERPASSING

厦门市梧村隧道为软岩浅埋大跨隧道,施工影响区域内楼房密集,在隧道施工过程中开展数值模拟与现场监测相结合的研究工作。根据有限元计算和现场监测成果,结合施工措施对隧道施工过程中楼房的安全运行情况进行全面深入的研究。研究成果表明:采用全断面帷幕注浆对提高全风化花岗岩强度具有一定的效果,但对上方楼房的上抬作用很小;采用地面注浆抬升措施控制楼房下沉效果明显,楼房的累计沉降值大多在30mm以内,满足设计要求;由于注浆设备数量不足,地面注浆没能达到全面均匀抬升楼房的效果,楼房不均匀沉降状态的反复波动催生新裂缝出现并使原有裂缝表现活跃;隧道下穿楼房的CRD法施工开挖顺序宜为CRD1→CRD2→CRD3→CRD4,这对控制楼房沉降有一定的效果。

Wucun tunnel in Xiamen City is shallow-buried large-span tunnel with soft rock,which underpass intensive buildings. The research work of combining numerical simulation with on-site monitoring is conducted in the process of tunnel construction. According to the results of finite element analysis and on-site monitoring data, combining with construction measures,comprehensive research are carried out on the safety of building during the construction. The research results show that the strength of completely decomposed granite can be improved by full-face curtain grouting,but it has little effect on uplifting the above building. Nevertheless,surface grouting has obvious effect on controlling the settlement of the above building,and the accumulative settlements of most monitoring points are less than 30 mm,which meet the design requirements. Because of the insufficient grouting equipment,the building can not be overall uplifted by surface grouting,which leads new cracks to appear and make the original cracks alive. CRD（center cross diagram） method is adopted to underpass the building,and its construction order should be CRD1→CRD2→CRD3→CRD4,which has certain effectivemess on the control of the above building settlement.