倾斜软硬地层中错台隧道施工灾害成因分析  

Analysis on the Construction Hazard Causes of Tunnels with Altitude Difference in the Tilted Soft-hard Interbedded Stratum

作　　者：刘宗韩 韩风雷[1,2] 张学富[1,2] 李宏亮 秦臻 赵一聪 LIU Zonghan;HAN Fenglei;ZHANG Xuefu;LI Hongliang;QIN Zhen;ZHAO Yicong(State Key Laboratory of Mountain Bridge and Tunnel Engineering,Chongqing Jiaotong University,Chongqing 400074;School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074;Xinjiang Communications Construction Group Co.,Ltd.,Urumqi 830016)

机构地区：[1]省部共建山区桥梁及隧道工程国家重点实验室,重庆交通大学,重庆400074 [2]重庆交通大学土木工程学院,重庆400074 [3]新疆交通建设集团股份有限公司,乌鲁木齐830016

出　　处：《现代隧道技术》2022年第6期197-207,共11页Modern Tunnelling Technology

基　　金：重庆市自然基金面上项目(cstc2019jcyj-msxmX0835);在渝本科高校与中科院所属院所合作项目(HZ2021009);中国博士后基金项目(2020M683710XB);西藏自治区自然科学基金项目(XZ202101ZR0036G);峨汉高速公路工程科研项目(LH-HT-45).

摘　　要：针对贵州某在建错台隧道围岩大变形、衬砌开裂等施工灾害问题,通过现场调查和数值模拟,研究倾斜软硬地层中隧道施工力学响应及灾害成因,并提出处治方法。结果表明,隧道开裂破坏的主要地质因素是软硬地层交错及地形变化,其中先行洞拱顶区域的开裂破坏受倾斜软硬地层影响更大,先行洞仰拱区域破坏程度受后行洞施工影响更大;从进洞陡峭区至出洞平坦区,先行洞受力和位移逐渐减小,最大差值分别为4.34 MPa、38.89 mm,先行洞衬砌开裂出现在拱顶左侧、左侧拱腰、仰拱回填位置,后行洞施工会使这三个部位拉应力分别增长29.84%、54.58%、130.61%;大坡度倾斜地层增大了岩层间剪切滑移,这使隧道沿倾斜面整体向右下方偏转,绝对位移过大会引起各部位不均匀变形,造成隧道结构不对称破坏;倾斜软硬地层中隧道施工需注意先行洞基底承载力不足、围岩大变形等问题,采取全断面注浆、施作临时仰拱及钢管树根桩等措施能有效防止开裂破坏。To solve the construction hazards of tunnels with altitude difference under construction in Guizhou, such as large deformation of surrounding rock and lining cracks, field investigation and numerical simulation are used to research the mechanical response to tunnel construction in the tilted soft-hard interbedded stratum and its hazard causes, and the treatment methods are put forward. The results show that the main geological factors causing tunnel cracking include soft-hard interbedded stratum and topographical changes. Cracking in the crown area is more affected by tilted soft-hard interbedded strata, and the extent of damage to the invert area is more affected by the construction of subsequent driving tunnel;from the steep area at the entrance to the flat area at the exit, the stress and displacement of advanced tunnel are gradually reduced, and the maximum differences are 4.34 MPa and 38.89 mm,respectively. The lining cracking of the advanced tunnel occurs on the left side of the crown, on the left shoulder and at the backfilling of the invert, and the subsequent driving tunnel separately increases the stress on these three locations by 29.84%, 54.58% and 130.61%;the high-gradient tilted strata increase the shear slip between rock formations so that the tunnel deflects to the bottom right, and if the absolute displacement is too large, it will cause uneven deformation of various locations, resulting in asymmetric damage to the tunnel structure;attention should be paid to the following problems during the tunnel construction in a tilted soft-hard interbedded stratum: insufficient bearing capacity of the advanced tunnel base, large deformation of surrounding rock, etc., and the methods, such as full-face grouting, temporary invert and root piles made of steel tubes, can effectively prevent cracking.

关 键 词：错台隧道 倾斜软硬地层 灾害成因 数值分析 

分 类 号：U457[建筑科学—桥梁与隧道工程]