【作者】 王靖华；

【导师】 陈寿根；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2011， 硕士

【摘要】 深圳地铁四号线二期工程上(上梅林站)-民(民乐站)区间,隧道于里程K9+105-K9+135(断层破碎带)下穿一次高压燃气管(Φ508×7.9,压力1.6MPa),燃气管埋设于人工填石(填土)层中,埋深约3.5m,距离隧道顶面约16.0m。此外附近还有一条广东大鹏天然气公司中600的燃气管道,DN1100、DN200两条供水管、一根Φ329.9×6.4供油管和地下电缆通过。在软弱富水地层进行隧道施工,如何有效控制围岩变形和地表沉降、减少地下水的流失是保证燃气管安全的重要途径,也是本工程顺利进行的前提。本文结合深圳地铁四号线二期工程的实例,通过理论分析、数值模拟(FLAC3D)、现场燃气管应力检测及沉降监测等手段,对断层破碎带下穿燃气管隧道围岩变形、地下水流失及燃气管的综合保护技术进行了较深入的研究,取得如下成果：(1)通过有限元软件(FLAC3D)进行围岩变形和位移沉降模拟计算得出：在软弱富水地层采用洞内管棚超前支护、小导管注浆能较好控制围岩变形和地表沉降,同时；结合地面分仓止水措施将地下水隔断于隧道开挖区域,能大大地减少了地下水的流失,有利于隧道掌子面的稳定及洞内施工的连续性。(2)由于该地段地处断层破碎带,地下水十分丰富,掌子面前方水头压力较大,若采取单纯的堵水措施,效果有限。超前钻孔引排水可以减少掌子面前方水头压力,同时通过钻孔的岩层探明掌子面前方15-20m范围地层情况,有利于施工的针对性。引排水管采用包有双层土工布滤网、周身开孔的钢管,反滤层能阻止泥砂随清水流入进水孔,有效控制了地层沉降。(3)针对次高压燃气管的保护,除了为控制围岩变形及地层沉降而采取的一系列措施外,从燃气管本身出发,对其焊缝及薄弱部位补强,削减管道上部荷载。在隧道施工的过程中,做好长期的监测工作,记录管道的沉降情况,同时；引入了管道无损应力检测技术,及时掌握管道应力变化情况。本技术可为今后类似隧道工程的管线检测提供较好的借鉴。更多还原

【Abstract】 The subway tunnel underpasses a gas pipline of sub-high presure (Φ508×7.9, pressure 1.6 MPa) located in fault fracture zone in the mileage of K9+105-K9+135 (fracture zone), at Shang (Shangmeilin Station)-Min (Minle Station) Section of StageⅡof Shenzhen Metro Line 4. The pileline buried in the artificial filled solid (rock) zone, about the depth of 3.5m to the surface,16.0m to the tunnel. In addition, a natural-gas pipeline (Φ600) of Guangdong Dapeng Company, two water pipes (DN1100, DN200), a power pipeline (Φ329.9×6.4) and underground cables exit nearby. How to control the surrounding rock deformation & ground settlement, and reduce the loss of groundwater effectively, is the key way to ensure the safety of the gas pipeline and also the prerequisite for the smooth’progress of the project for a tunnel construction in week & water-rich strata.The control of the surrounding rock deformation & ground settlement, the loss of groundwater and the pipeline protection technologies are researched and analysed in this paper based on the project of Stage II of Shenzhen Metro Line 4 through theoretical analysis, numerical simulation (FLAC3D), on-site gas pipe testing of stress monitoring and settlement. Some achievments obtained are as follows:(1) The simulation results of rock deformation and displacement of settlement conducted by using the finite element software (FLAC3D) show that:the advanced support of pipe roof and the small duct grouting can well control the deformation and the settlement, as well the partition-water-seal can seal the groundwater off the tunnel area, which is conducive to the stability of tunnel face and the construction of continuity.(2) As the site is located in the fault zone with rich groundwater and high water pressure, the effect is limited if the sealing measure taken only. Advanced drilling-wate-discharge in the face can reduce the water pressure effectively, reveal the conditions of the strata 15-20m in front as well. The pipe with whole body perforated and double geotextile filters packed can allow the flow of the groundwater while keep the sediment off.(3) For the protection of subhigh-pressure gas pipeline, besides the means of the control of rock deformation and settlement taken, the gas pipe itself is considered, the weak parts are reinforced, combining with the upper load reduction of the pipe. In the process of tunnel construction, long-term monitor of the pipe is conducted to record the settlement while a new technique of non-destructive stress measurement is introducd to inspect the pipe stress situation. This technique of pipeline detection can provide reference for the similar projects in future.更多还原