以厦门梧村隧道明挖段深基坑施工为例,对施工期间的支护结构自身安全以及对周边环境的影响相应开展安全监测研究工作。监测内容包括巡视检查、沉降、水平位移、深部位移、地下水位、锚索轴力和爆破振动等。结合场区地质条件和现场施工情况,分别对支护结构及周边环境的监测成果进行较为全面的分析。研究结果表明:地质条件是引起变形监测成果分布差异的主要因素;新临空面的出现会产生较大的位移,对支护桩的稳定有一定的影响:深基坑采用钻爆法开挖时,需要进一步验证边坡支护设计参数选取的合理性。对施工过程中出现的支护桩位移速率过大、边坡滑塌等工程险情进行跟踪监测和分析,监测成果表明相应的处理措施是合理有效的。
Taking the deep foundation pit of open-cut tunnel in Xiamen City for example, safety monitoring is carried out on the surrounding environment as well as on supporting structure itself during the construction period. The monitoring measures for the safe construction of deep foundation pit mainly include tour check, settlement, horizontal displacement, deep displacements, underground water level, axial stress of anchor and blasting vibration, etc.. Combined with the geology condition and in-situ construction environment, the monitoring results are comprehensively analyzed on the surrounding environment as well as on supporting structure. Research results show that geology condition is the main factor that causes the difference of deformation distribution. Large displacement will appear after the creation of new flee face, so the stability of the retaining pile are affected. When the blasting excavation is applied on the deep foundation pit, the selection of design parameters are demanded to further verify their rationality. Monitoring and analysis are carried on dangerous situation such as high displacement velocity of the supporting pile, landslide and collapse of slope etc.; and the monitoring results show that emergency measures relevant to the dangerous situation are reasonable and effective.