近距离下穿既有线的地铁盾构隧道端头加固，不仅要保证盾构出洞时地层的稳定性、避免发生涌水坍塌，还要防止加固施工及盾构掘进出洞施工引起既有线路的沉降超标。尤其对正在运营的地铁线路而言，其对轨道变形高度敏感，产生的位移超过一定标准将会对铁路车辆的运营安全带来极大的隐患。以深圳地铁7号线和9号线盾构区间为例，根据工程所处的环境，对静压循环注浆控制技术、扩散性好凝胶时间可控的新型材料进行研究应用，并利用自动化监测技术。盾构端头井加固达到了要求，确保了盾构安全出洞，还使临近既有线变形量控制在规范要求的范围内。

The shieldreceiving section of the running tunnels of Line 7 and Line 9 of Shenzhen Metro crosses closely underneath existing Line 1 of Shenzhen Metro. The consolidation of the shieldreceiving section should not only ensure the stability of the ground during shield arriving, but also should ensure that the settlement of the existing Metro line induced during ground consolidation and shield arriving does not exceed the limit value. In the paper, ground consolidation technologies, including staticpressure circulating grouting technology, application of new grouting materials with good diffusion property and controllable gel time and automatic monitoring technology, are studied. The mentioned technologies have been used in the project and good effect has been achieved.