宜万铁路野三关隧道高压富水充填溶腔溃口处理技术

Technology for Treating Burst Port of Filling Solution Cavity with High-pressure and Rich Water of Yesanguan Tunnel on Yichang-Wanzhou Railway

研究目的：宜万铁路野三关隧道602溶腔双层初期支护完成后,受地表强降雨影响,使溶腔内形成高压水,从而击穿双层初期支护。通过实施高位泄水支洞降低水压力,采取注浆堵水固结溃口块石堆积体,以及超前管棚预支护措施,完成溃口处理。研究结论：采取注浆技术和管棚预支护措施,可以有效固结块石堆积体。采用大扭矩、高转速钻机,当扭矩为1 200-2 000 N.m、转速为300-500 rpm时,钻穿一榀I20钢架时间为30-1 h 30 min。采用硫铝酸盐水泥单液浆和普通水泥-水玻璃双液浆组合型注浆材料配套体系,按由下到上、先外后内、间隔跳孔的注浆顺序,采取合理分段长度进行前进式分段注浆,按定量定压相结合原则,可以解决周边排水条件下的注浆控制。块石堆积体经注浆改良后,施作Ф76 mm管棚超前预支护,能保证隧道溃口段的安全施工。

Research purposes： After completion of the double primary supports for solution cavity 602 of Yesanguan Tunnel on Yichang-Wanzhou Railway,the high-pressure water formed in the solution cavity to breakdown the double primary supports because of the heavy rainfall.The series of methods and measures were adopted and taken for treating the burst port,such as lowering water pressure by building the high drainage branch tunnel,plugging water and consolidating block stone debris at burst port by grouting and adopting advanced pipe-shed support.Research conclusions：The block stone debris can be consolidated by grouting and pipe-shed support.The time of drilling through an I20-beam is between 30 mins and 90 mins when using a driller with the torque of 1 200 N·m to 2 000 N·m and rotational speed of 300 rpm to 500 rpm.The grouting under the local condition of water drainage can be controlled by using compound grouting material system of sulphoaluminate cement slurry and ordinary cement-soluble glass double slurry,following the grouting sequences of from down to up,from outside to inside and grouting every other hole,conducting sectional grouting with reasonable section length and combing a certain grouting number with a certain grouting pressure.After the block stone debris is improved by grouting,it can be used as an advanced Ф76 mm pipe-shed support to ensure the construction security at burst port.