公路盾构隧道超深基坑开挖的施工控制技术

Construction Control Technique for Deep Foundation Pit Excavation of Highway Shield Tunnel

基坑工程存在的不确定因素较多,科学有效的监控措施是保证安全施工的关键。根据钱江隧道试验段深基坑工程所处的水文地质条件和周边环境特点,从地面沉降、地连墙测斜、支撑轴力、地下水位变化等4个方面对深基坑开挖的施工控制技术进行了研究。以实测数据为基础,分析提出了钱塘江围垦区域地面最大沉降和地连墙最大侧向变形两个指标的建议控制值。实际工程表明,该施工监测和控制方案效果较好,可为其他类似工程提供参考。

Good monitoring and control measures are necessary to ensuring safety construction, because there are many uncertainty factors in deep foundation engineering. According to hydrogeologic conditions and circumference environments of Qiantang River Tunnel＇s deep foundation pit in experimental section, the control technique for deep foundation pit excavation is researched from four indexes as ground settlement, continuous concrete wall lateral deformation,bearing beam axial force and groundwater level fluctuation. And two suggested controlling values of maximal ground settlement and continuous concrete wall lateral deformation in Qiantang River reclamation land are put forward based on measured values. The results indicate that this control technique is successful and can be referenced for other similar engineering.