盾构隧道下穿高耸结构筏板基础的影响

Influence of metro shield tunneling crossing high-rise raft foundation structure

为研究盾构隧道下穿施工对上方高耸结构筏板基础的影响,应用数值模拟与工程实测相结合的方法,对盾构隧道下穿高耸结构筏板基础建筑物过程中的变形响应规律、加固措施等进行了研究.研究成果表明:盾构隧道施工对沉降监测点产生影响的纵向水平区间约为监测点前3D(D为盾构隧道直径)至监测点后3D;倾斜监测点产生影响的纵向水平区间约为监测点前D至监测点后5D.盾构隧道穿越前对高耸结构进行注浆预加固可有效减小筏板基础倾斜及高耸结构层间位移角.高耸结构水平位移随着隧道施工的进行处于动态变化中,对施工过程中出现的较大层间位移应充分重视.

In order to research the influence on raft foundation of high-rise structure caused by the construction of shield tunnel underneath, this paper used the numerical simulation combined with onsite surveying, and studied the deformation rules and strengthening measure caused by metro shield tunneling crossing high-rise raft foundation building. The calculation show that when the shield tunnel excavation face away from the monitoring sites 3 D(D:Shield tunnel diameter)distance, the raft foundation began to appear settlement. After 3 D spacing through monitoring sites, the raft foundation settlement gradually stabilized; the shield tunnel excavation face away from the monitoring sites D distance, the raft foundation began to appear tilted. After 5 D spacing through monitoring sites, the raft foundation tilt gradually stabilized. Before advancing of the shield machine, grouting reinforcement under the raft foundation can effectively reduce the incline of the raft foundation and story drift. With the construction of the tunnel, the horizontal displacement of the high-rise structure is changing dynamically, and the larger story drift which occurred in the process of construction should pay more attention.