地铁施工盾构空推过既有矿山法隧道施工组织设计——以广州地铁6号线二期工程为例

以广州地铁6号线二期工程盾构空推过既有暗挖法隧道工程为例，采用矿山法施工初期支护后由盾构空推安装预制管片作为永久二次衬砌；为了有效控制隧道轴线偏差超限、管片错台、渗漏、破损等质量缺陷，采取分阶段制定施工组织措施，通过优化施工工艺、人料机和环境等方面落实质量控制措施，使工程符合《盾构法隧道施工与验收规范》要求。得出以下结论： 1）初期支护和导向平台的前期施工质量和后期超欠挖处理，直接影响隧道轴线偏差； 2）回填料堆放的数量和位置决定空推进度和盾构推力的大小，隧道背后间隙的及时注浆填充，是质量保证的必要条件。通过分析计算此类工程中回填料堆放实测值的110%，同步注浆量达到80%，后期补充注浆以压力控制为主。

Organization Design of Shield Crossing Existing Mined Tunnel without Load:Case Study on Phase 2 Project on No. 6 Line of Guangzhou Metro

In this paper, the shield tunneling crosses existing tunnel constructed by mining method without load is presented in detail. The conclusions drawn are as follows: 1)The primary construction quality and late over/short break of primary support and guide platform effect tunnel axial line directly. 2) The quantity and location of backfilling material effect the forcing load of shield advancing directly. The analysis and calculation results show that the actual monitoring value of backfilling material reaches 110%, the synchronous grouting volume reaches 80%, and the stress control lead a predominant effect during supplemental grouting.