地铁站地下连续墙穿越人防隧道施工技术

结合合肥地铁一号线明光路站地下连续墙施工工程,根据地下人防隧道拱顶埋深高度、地下连续墙和人防结构相对位置,采取相应的施工措施:拱顶埋深较小时采用板桩围护开挖,修筑封堵墙,破除人防回填后加固;埋深较大时采用全套管钻机清障,冲击钻回填后加固;地下连续墙与人防同槽时采取旋挖钻钻孔,人防隧道两端粘土回填至地面,隧道中部砂浆填充至洞顶,粘土回填至地面后加固。解决了地铁站超深地下连续墙在复杂地质且有人防隧道时的成槽难题,保证了基坑的安全。

Construction Technology of Diaphragm Walls Crossing Civil Air Defense in Metro Station

Combined with diaphragm walls construction of Hefei Metro line 1, according to the buried depth of civil air defense dome and the relative position between civil air defense and diaphragm walls, the corresponding technology were taken, such as: when the depth of civil air defense dome was shallow, sheet pile enclosure excavation, constructing sealing wall, reinforcement foundation after backfill, when the dome is deep, cleaning up the obstacles by casing rotator, backfill foundation by electric impact drill, reinforce foundation by high pressure jet grouting pile, and when diaphragm wall had the same groove as civil air defense, rotary drilling rig was taken for boring, backfill both sides of the tunnel with clay to ground, backfill middle tunnel with mortar to the dome. The problem of construction technology about ultra-deep diaphragm walls under complicate geological conditions and obstacles was solved and the safety of foundation was ensured.