南水北调西四环暗涵工程回填灌浆施工

回填灌浆作为南水北调北京段西四环暗涵工程浅埋暗挖法施工的一道主要工序,也是有效控制地面沉降的一种重要手段,其施工质量的优劣直接影响建筑物的稳定与安全。南水北调西四环暗涵工程的浅埋暗挖法施工中的回填灌浆,采取孔外循环、孔内填压的方式,并在孔口设止浆塞和回浆装置,以保证围岩的灌浆压力;此外,对灌浆中断、串浆、漏浆、吸浆量较大孔等特殊情况采取了一系列处理措施,以保证施工质量。

The Backfill Grouting for the Underground Culvert at West Ring Road of the South-North Water Transfer Project

The backfill grouting is a principal construction work in the tunneling for shallow covered underground culverts at the Western 4th ring road of the South-North Water Transfer project.It is also a key measure to effectively check ground settlement.So the quality of the construction work will have a direct impact on the stability and safety of building structures.The external circulation and internal pressure building were adopted in the backfill grouting in the tunneling for shallow covered underground culverts at the Western 4th ring road of the South-North Water Transfer project.In addition,the grout stops and grout return devices are provided at the hole collars to maintain the grouting pressure on the surrounding rock.In order to guarantee the quality of grouting,many measures have been taken for abnormal conditions such as interruption of grouting operation,grout leakage,cross grouting,and exceptionally high grout acceptance and etc..