岩溶基底隧道拱顶沉陷三段四层关键技术研究  

Study on “three-section and four-layer” reinforcement technology of tunnel vault subsidence in the karst basement

作　　者：覃剑文 李海波 潘光明 田月明 QIN Jianwen;LI Haibo;PAN Guangming;TIAN Yueming(Guangxi Geological Environment Monitoring Station,Guigang,Guangxi 537100,China;No.4 Prospecting Team of Shandong Coal Geology Bureau,Weifang,Shandong 261200,China)

机构地区：[1]广西地质环境监测总站,广西贵港537100 [2]山东省煤田地质局第四勘探队,山东潍坊261200

出　　处：《中国岩溶》2022年第5期746-758,共13页Carsologica Sinica

摘　　要：为有效治理岩溶基底城市隧道拱顶地层沉陷地质灾害,在充分探明沉陷区水文地质、工程地质特征的基础上,提出了“三段四层控制技术”,将治理区划分为沉陷区重点加固段、影响区次重点加固段和超前加固段;再根据治理深度和治理顺序进一步把沉陷区重点加固段分为顶部阻浆层、拱顶止浆垫层、拱顶加固层和中间加固层,研究了每段、每层注浆加固机理、浆液类型选择和控制注浆参数。研究成果表明,采用孔内复合止浆技术满足不同深度地层分段注浆为主、垂直孔和定向斜孔相结合,充填注浆、劈裂-挤密注浆相结合,以速凝浆液为主、单液水泥浆为辅,严格控制安全注浆参数,是“三段四层控制技术”安全有效注浆的技术关键,该技术方案在岩溶基底城市隧道拱顶地层沉陷地质灾害治理方面,取得了较好的注浆加固效果,有良好的推广应用价值。In order to effectively control the geological disaster of tunnel vault subsidence in the karst basement, the "three-section and four-layer" control technology is proposed, based on the full analysis of engineering geology and hydrogeological characteristics of the subsidence stratum. In this technology, the treatment area is divided into the key reinforcement section, the sub-key reinforcement section of the affected area and the pre-excavated reinforcement section. According to the treatment depth and order, the key reinforcement section of the subsidence area is divided into the top slurry barrier layer, the vault cushion layer of slurry-stopping, the vault reinforcement layer and the intermediate reinforcement layer.In terms of grouting mechanism, filling grouting and splitting-compacting grouting are adopted in both the top slurry barrier layer and the intermediate reinforcement layer. The alternate mode with filling-splitting-compacting grouting is implemented in the intermediate reinforcement layer, and the filling grouting mode is adopted in the vault cushion layer of slurry-stopping. Splitting-compacting grouting is conducted in both the pre-excavated reinforcement section and the sub-key reinforcement section in the affected area. In order to reduce the leakage of grout in the top slurry barrier layer and vault cushion layer of slurry-stopping, C-GT quick setting mixed grout is selected, and the initial setting time of the grout is controlled at 30-50 seconds, while the final grouting pressure is no more than 0.5 MPa and 0.8 MPa. In order to realize the effective diffusion of slurry in the vault reinforcement layer and intermediate reinforcement layer, the initial setting time of C-GT mixed slurry is extended to 50-90 seconds, even up to 150 seconds, and the final grouting pressure is up to 0.8-1.2 MPa. To improve the slurry diffusion and overall reinforcement strength of the pre-excavated reinforcement layer and the sub-key reinforcement layer in the affected area, the alternate and continuous grouting

关 键 词：岩溶基底 隧道 地层沉陷 灾害治理 分段注浆 

分 类 号：U457[建筑科学—桥梁与隧道工程] TU761.11[交通运输工程—道路与铁道工程]