深埋富水黄土隧道地表深孔袖阀管注浆加固机理及效果分析  

Mechanism and Effect Analysis of Surface Deep-hole Sleeve Valve Pipe Grouting Reinforcement in Deep-buried Water-bearing Loess Tunnel

作　　者：张民庆 张虎元[2] 谢君泰[3] ZHANG Minqing;ZHANG Huyuan;XIE Juntai(Engineering Management Center of China State Railway Group Co.,Ltd,Beijing 100844;Lanzhou University,Lanzhou 730000;China Railway First Survey and Design Institute Group Co.,Ltd,Xi'an 710043)

机构地区：[1]中国国家铁路集团有限公司工程管理中心,北京100844 [2]兰州大学,兰州730000 [3]中铁第一勘察设计院集团有限公司,西安710043

出　　处：《现代隧道技术》2023年第1期219-224,共6页Modern Tunnelling Technology

基　　金：中国国家铁路集团有限公司科技研究开发计划课题(P2019G038)。

摘　　要：黄土具有“强度低、变形量大、自承能力小、工程性质差”的特点,且对水特别敏感,一旦遇水,强度明显降低,工程性质急剧恶化。因此,富水黄土隧道的施工难度极大、安全风险极高。银川至西安高铁上阁村隧道穿越富水黄土地层,埋深102 m。施工中,通过降水试验无法取得明显的降水效果,同时隧道围岩变形大、进度缓慢。鉴于此,开展了地表深孔刚性袖阀管注浆试验研究。研究结果表明:(1)地表深孔袖阀管注浆可以有效加固地层,提高其自稳能力。加固机理主要表现为浆液对竖向原生节理的填充阻水作用、浆液结石体的空间骨架作用;(2)注浆后隧道拱顶累计沉降量明显减小,变形速率降低,仰拱闭合时间提前,隧道开挖进度可达到60~80 m/月。与未注浆工况相比,施工进度提高了3倍以上;(3)通过注浆,隧道基底黄土地层承载能力可提高3倍以上,从而可保证高铁隧道的长期运营安全。Loess is characterized by "low strength, large deformation, small self-supporting capacity and poor engineering properties", and is particularly sensitive to water. Once it meets water, the strength will be significantly reduced, and the engineering properties will deteriorate sharply. Therefore, the construction of the water-bearing loess tunnel is extremely difficult and the safety risk is extremely high. The Shangge Village tunnel on Yinchuan-Xi′ an High-speed Railway passes through the water-bearing loess stratum, with a buried depth of 102 m. During the construction, no obvious dewatering effect can be achieved through the dewatering test, and the surrounding rock of the tunnel is deformed greatly and the progress is slow. In view of this, an experimental study on grouting of surface deep-hole rigid sleeve valve pipe is carried out. The results show that:(1) the grouting of the surface deep-hole sleeve valve pipe can effectively strengthen the stratum and improve its self-stability. The reinforcement mechanism is mainly the filling and water-blocking effect of grouting on vertical primary joints and the spatial skeleton effect of grout stones.(2) After grouting, the accumulated settlement of the tunnel vault is obviously reduced, the deformation rate is reduced, the invert closure time is advanced, and the tunnel excavation progress can reach 60 ~ 80 m/month.The construction schedule has been improved by more than three times compared to that of the ungrouted case.(3)Through grouting, the bearing capacity of the loess stratum at the tunnel base can be increased by more than 3times, thus ensuring the long-term operation safety of high-speed railway tunnels.

关 键 词：深埋隧道 富水黄土 地表深孔袖阀管注浆 注浆机理 注浆效果 

分 类 号：U455.49[建筑科学—桥梁与隧道工程]