由于车站不能按时提供盾构接收条件,南宁地铁2号线石子塘站—建设路站区间(石建区间)需增设临时接收竖井。按照常规方法,在竖井内衬结构完成后才能进行盾构接收,由此将造成建设工期长、建设成本高、施工工序多等问题。为解决以上问题,通过采取加大并密排对应盾构进入接收竖井位置的围护桩、以水平环梁代替对撑或外拉锚、在洞门位置用玻璃纤维筋代替钢筋、采用特制的洞门密封装置、灵活设置临时封底、优化接收前盾构掘进参数,并辅以降水、监测等措施,不必施作竖井内衬结构,盾构直接切削桩体进入竖井,安全、快速地实现了盾构接收,为石建区间按时贯通提供了保障。
Due to the fact that the station cannot provide the shield receiving conditions on time, a temporary receiving shaft should be added to Shizitang StationJianshe Road Station Section on Nanning Metro Line 2. According to the conventional method, the shield can be received after the shaft lining structure is completed, which will cause problems such as long construction period, high construction cost and multiple construction procedures. Hence, in order to solve the abovementioned problems, a series of technologies, i.e. adopting enlarged and closepacked piles at the position of shield machine entering the receiving shaft, replacing the support or the outer pull anchor by horizontal ring beam, using the glass fiber rib instead of the steel bar at the tunnel portal, using special sealing device for tunnel portal, flexible setting of the temporary sealing bottom, optimization of the tunneling parameters before shield receiving, and the precipitation, monitoring and other measures, are adopted. The shield machine can directly cut the pile into the shaft without the need to apply the shaft lining structure, and the shield receiving has been realized safely and quickly, which can provide guarantee for the completion of the project.