超浅埋下穿高速公路暗挖隧道变形控制施工技术研究

发布时间：2019-03-19 12:48

【摘要】：深圳求水山隧道下穿机荷高速公路收费站,地面车流量大,隧道超浅埋并穿越回填土富水地层,结构松软,施工沉降难以控制,施工不当会引起隧道变形坍塌和路面沉陷,危及地面行车安全。为找出控制沉降的关键步序,运用FLAC3D软件对施工过程进行沉降分析,先确定超浅埋隧道在下穿富水软土地层条件下产生变形的原因,再对隧道施工各工序的时间和步距数据进行调研与分析。提出优化后隧道施工工法(双侧壁导坑微台阶工法)及拱脚加固、掌子面封闭、地下水处治、开挖及支护工序卡控、监控量测等控制变形技术措施,成功解决变形沉降难题,将拱顶下沉控制在45.6 mm左右,地面沉降控制在184 mm左右,化解了工程安全风险,确保了隧道施工和地面行车安全。
[Abstract]:Shenzhen Xushuishan Tunnel passes through the toll station of the motorway with high traffic flow on the ground, supershallow burying of the tunnel and traversing the backfill soil and rich water stratum, the structure is soft, the construction settlement is difficult to control, the improper construction will cause the tunnel deformation collapse and the road surface subsidence. Endangers the safety of driving on the ground. In order to find out the key sequence of controlling settlement, the settlement analysis of construction process is carried out by using FLAC3D software, and the cause of deformation of ultra-shallow tunnel under the condition of water-rich soft soil is determined first. Then the time and step data of each procedure of tunnel construction are investigated and analyzed. This paper puts forward some technical measures to control deformation, such as optimized tunnel construction method (double-sidewall guide pit micro-step construction method) and arch foot reinforcement, palm surface sealing, groundwater treatment, excavation and supporting procedures blocking, monitoring measurement and other technical measures to control deformation, and successfully solves the problem of deformation settlement. The vault subsidence is controlled at about 45.6 mm, and the ground subsidence is controlled at about 184 mm. The engineering safety risk is solved and the tunnel construction and ground driving safety are ensured.
【作者单位】：中铁一局集团有限公司广州分公司;
【分类号】：U455.4

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