豆砾石回填灌浆工艺在复合式TBM施工中的应用

在以往的城市地铁或者轻轨工程中,多采用盾构法施工,管片背后充填采用同步注浆工艺。虽然同步注浆工艺已经使用多年,但其缺陷明显,返浆卡盾、管片上浮、注浆初期管片承载力不足下沉、管片错缝等问题一直存在,由此造成管片接缝渗漏水现象较为严重。为此,结合重庆轨道交通二号线铜锣山隧道施工实践,采用了基于单护盾的复合式TBM施工设备,并采用豆砾石回填灌浆工艺,即先进行管片背后充填,然后依次灌浆,最终取得了成功。该工艺的探索成功,为我国多山城市的轨道交通施工提供了一种新的思路和选择。

The Application of the Pea-Sized Gravel Backfilling and Grouting Technique to the Construction of the Composite TBM

In the past construction of urban tubes and light-track railways,the shield construction method was mostly used,in which case the back of the pipe segments was backfilled by the synchronous grouting filling technique.Although the synchronous grouting technique has been used for many years,there are still some obvious defects in this method,such as the returning of the grouted mortar and the blocking of the shield,the up-floating of the segments,the settling of the segments due to the lack of bearing capability during the initial grouting,the displacement of segments,and so on,all of which often result in the problem of serious water leakage from the segment joints.In order to overcome these defects,the construction equipment of the single-protective-shield-based composite TBM is used for the construction of the Tongluoshan Mountain Tunnel of Line Two of the Chongqing Rail Transit,with the pea-sized-gravel backfilling and grouting technique adopted,namely,first backfilling the back of the segments,then performing grouting in normal sequence and finally the construction process proving a great success.The successful exploration of this technique provides a new thinking way and a new option for the rail construction in mountainous cities of China.