多孔叠交隧道盾构施工关键技术研究

为确保多孔叠交隧道能安全快速地施工,以南宁轨道交通1号线和2号线叠交段为例,分析了叠交隧道"先下后上"施工的优势。结合现场施工情况,对叠交隧道施工的二次固结、注浆加固、下部隧道支撑加固和掘进参数控制等关键技术进行分析,给出叠交段的加固范围,分析钻注一体和台车+风钻2种施工方法以及穿行式同步移动支撑台车和可拆卸环形钢支架2种支撑方法的适用条件。对于叠交隧道盾构掘进参数控制技术,从掘进参数、盾构姿态和同步注浆3方面提出了建议。

Study of Key Technologies for Shield Tunneling of Overlapping Tunnels

Taking the overlapped section between Nanning Metro Line No. 1 and Line No. 2 for example, the advantages of the construction scheme of “upper tunnel after lower tunnel” are analyzed so as to ensure the rapid and safe construction of overlapping tunnels. And then the key technologies, i.e. secondary consolidation, grouting reinforcement, support reinforcement of lower tunnel and driving parameter control, are studied based on site construction conditions; the reinforcement range of the overlapped section is given; and then the applicable conditions of two kinds of construction methods, such as integration of drilling and grouting and trolley + pneumatic drill, and two kinds of supporting methods, such as walking synchronous mobile support trolley and removable ring steel bracket, are analyzed. Finally, some suggestions on the control technology of driving parameter of shield tunneling are proposed in terms of driving parameters, shield altitude and synchronous grouting.