软弱富水地层大断面隧道挑顶施工技术研究  

ROOF-RIPPING CONSTRUCTION TECHNOLOGY FOR LARGE CROSS-SECTIONAL TUNNEL IN SOFT AND WATER-RICH STRATUM

作　　者：杜传球 李馨芳 张博 陈乾 张晓平 DU Chuanqiu;LI Xinfang;ZHANG Bo;CHEN Qian;ZHANG Xiaoping(The 2nd Engineering Co.,Ltd.of China Railway 12th Bureau Group,Taiyuan 030032,China;The Key Laboratory of Safety for Geotechnical and Structural Engineering of Hubei Province,School of Civil Engineering,Wuhan University,Wuhan 430072,China;State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan 430072,China;China Rail Way Construction Yunnan Traffic Construction Management Co.Ltd.,Kunming 650200,China)

机构地区：[1]中铁十二局集团第二工程有限公司,太原030032 [2]武汉大学土木建筑工程学院,岩土与结构工程安全湖北省重点实验室,武汉430072 [3]武汉大学水资源与水电工程科学国家重点实验室,武汉430072 [4]中铁建云南交通建设管理有限公司,昆明650200

出　　处：《工程地质学报》2023年第3期1116-1123,共8页Journal of Engineering Geology

摘　　要：复杂地质条件大断面隧道斜井进正洞挑顶施工风险高,交叉口处空间结构复杂、应力转化频繁,支护结构强度难以有效抑制围岩变形,导致塌方事故威胁施工安全。为了提高软弱富水地层大断面隧道挑顶施工的安全性,本研究以三清高速公路西山营隧道斜井进正洞段挑顶施工为例,提出了在交叉口处采用门架上部拱架和门架加强环联合支护的新型支护结构,优化了门架加强环支护强度及挑顶施工工艺,阐述了垂直挑顶进洞施工方案、施工流程和施工要点。研究结果表明,所提的新型支护结构减少了开挖面围岩的超挖面积与变形量,加强了应力集中部位的支护强度与稳定性。所提工法的施工用时仅20余天,相较于传统工法节约近一倍工期,通过合理组织工序加快了斜井进正洞段交叉口处的施工进度。隧道现场监测结果表明,挑顶施工期间交叉口处围岩收敛变形及稳定性控制满足施工要求。总体上所提工法的技术原理简单、实际操作性强,可为类似工程地质条件下大断面隧道挑顶施工提供经验参考与技术指导。Roof-ripping construction for a large cross-sectional tunnel is a dangerous procedure under complex geological conditions.The spatial structure of the intersection is complex,the stress transformation is frequent,and the support strength is difficult to effectively restrain the surrounding rock deformation,which results in collapse accidents and threatens the construction safety.This paper aims to improve the safety of roof-lifting construction of large cross-sectional tunnel in soft and water-rich stratum.It is based on the construction of the inclined shaft into the main tunnel in Xi Shanying tunnel of Sanqing expressway.It develops a new structure of the combined support of the upper arch of portal frame and the strengthened portal frame at the intersection.It optimizes the supporting structure strength of the strengthened portal frame and roof-ripping construction technology.It studies the construction scheme,construction process and key points of vertical roof-lifting.The results show that the combined supporting structure reduces the over-excavation area and deformation of the surrounding rock,and strengthens the support strength and stability of the stress concentration area.The construction schedule of the proposed method takes only 20 days,which saves nearly one time compared with the traditional construction method,and the construction progress of the intersection from the inclined shaft into the main tunnel is accelerated by the rational organization of the process.The results of tunnel field monitoring show that the convergence deformation and stability control of the surrounding rock at the intersection of the tunnel during the roof-ripping construction meet the construction requirements.In summary,the technical principle of this method is simple and practical.The method can provide experience reference and technical guidance for the construction of large cross-sectional tunnels under similar engineering geological conditions.

关 键 词：软弱富水 大断面 挑顶施工 交叉口 门架加强环 

分 类 号：U455[建筑科学—桥梁与隧道工程]