富水弱成岩砂岩地层隧道挑高段施工技术研究

发布时间：2018-04-04 07:13

本文选题：隧道施工技术　切入点：注浆　出处：《山东大学》2017年硕士论文

【摘要】：胡麻岭隧道第三系富水弱成岩粉细砂岩地段隧道施工难度巨大,第三系富水弱成岩粉细砂岩地层在开挖扰动后自稳能力差,掌子面极其不稳定,现场施工过程中极易发生小型坍塌,涌水涌砂频发,初支易变形、沉降量大。第三系富水弱成岩粉细砂岩遇水后工程力学特性发生很大改变。通过土工试验,对第三系富水弱成砂岩的工程力学特性及不同含水率情况下抗剪强度的变化进行研究。为破解施工难度大提供解决问题的方向。现场实测了胡麻岭隧道围岩松动圈的大小,在第三系富水弱成砂岩地层,围岩松弛带厚度达到4m,为制定第三系粉细砂岩围岩止水加固提供直接的参数。本文结合胡麻岭隧道4号斜井挑高段的施工,对在胡麻岭隧道施工中创新采用的施工工法进行了详细的介绍。胡麻岭隧道第三系富水弱成岩粉细砂岩地层中隧道施工,创新性的采用了超前HCH-I高分子注浆材料替代了传统的注浆材料水泥浆及水泥浆-水玻璃双浆液。通过对隧道岩体超前预注HCH-I高分子材料,很好的加固了围岩,封闭出水点。第三系富水弱成岩粉细砂岩渗透系数小,降水难度,掌子面降水时部分砂岩随着水流失造成支护背后空洞严重时甚至会支护失稳,胡麻岭隧道在世界范围内首次将深井降水技术引入到山岭隧道施工降水中。通过在隧道顶部山体建设降水深井,成功的降低了隧道所在位置的水头,同时在隧道内部采用台阶轻型井点降水及超前水平真空降水,共同为隧道施工提供安全保障。在隧道挑高段施工中,选择了斜井直接进入正洞横向贯通单侧喇叭状挑高的施工方案。通过多种创新性的工法工艺,为胡麻岭隧道第三系富水弱成岩粉细砂岩隧道施工提供了一个安全的施工环境。胡麻岭隧道第三系砂岩地层隧道施工中采用的工法工艺,对在地层环境类似开展的同类工程,有很大的推广价值。
[Abstract]:It is very difficult to construct the tunnel in Humaling tunnel, which is rich in water and weak diagenetic fine sand rock. The formation of water rich and weak diagenetic fine sand rock of the tertiary system has poor self-stability after excavation disturbance, and the face of palm is extremely unstable.It is easy to occur small-scale collapse in site construction process, water gushing sand frequent, the initial branch is easy to deform, and the amount of settlement is large.The engineering mechanical properties of Tertiary water-rich weak diagenetic silty sand rock changed greatly.Based on the geotechnical tests, the engineering mechanical properties of the Tertiary water-rich and weakly formed sandstone and the variation of shear strength under different moisture content are studied.In order to solve the construction difficulties to provide a solution to the problem.The size of surrounding rock loose circle of Humaling tunnel is measured on the spot. In Tertiary water-rich and weak sandstone formation, the thickness of surrounding rock relaxation zone is up to 4 m, which provides direct parameters for the formulation of water sealing and strengthening of Tertiary fine silt rock surrounding rock.Combined with the construction of the No. 4 inclined shaft in Humaling Tunnel, this paper introduces in detail the innovative construction method used in the construction of Humaling Tunnel.In the construction of the tunnel in the Tertiary water rich and weak diagenetic fine sand strata, the advanced HCH-I polymer grouting material was used to replace the traditional grouting material cement slurry and cement slurry-water glass double slurry.Through the advance injection of HCH-I polymer material to the tunnel rock mass, the surrounding rock is well strengthened and the water point is closed.The permeability coefficient of Tertiary water-rich weak diagenetic fine silty sand rock is small, the precipitation is difficult, and some sandstones even lose stability when the water loss results in serious voids behind the support.For the first time in the world, the deep well dewatering technology has been introduced into the mountain tunnel construction precipitation.Through the construction of deep well of dewatering on the top of the tunnel, the water head in the tunnel position is reduced successfully, and the step light well point dewatering and the leading level vacuum dewatering are adopted in the tunnel interior, which provides the safety guarantee for the tunnel construction together.In the construction of the high section of the tunnel, the construction scheme of the inclined shaft directly entering the main hole is chosen.Through a variety of innovative engineering techniques, this paper provides a safe construction environment for the construction of the Tertiary water-rich and weakly diagenetic silty sand tunnel in Huamaling Tunnel.The engineering technique used in the construction of the tertiary sandstone formation tunnel in the Humaling Tunnel has great value in popularizing the similar projects carried out in the formation environment.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U455.4

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