大断面浅埋偏压隧道CRD法施工工序研究

发布时间：2018-03-25 22:32

本文选题：浅埋隧道　切入点：CRD法　出处：《现代隧道技术》2015年03期

【摘要】：文章以良村隧道CRD法施工为工程背景,布设了变形监测点及内力测试元件,分析了CRD法施工隧道围岩变形情况及结构内力特征,并对CRD法施工隧道在不同开挖顺序下的开挖过程进行了数值模拟,分析比较了不同开挖顺序时的围岩位移、应力变化情况。结果表明:CRD法对各分部施工工序影响较大,且各分部对拱顶下沉的影响程度从大至小依次为1部、2部、3部和4部;隧道内侧围岩压力大于外侧,钢支撑内力均为压应力,且拱腰位置轴力大于其它部位。比较隧道开挖变形的差异以及结构的受力特点,结合数值分析结果,得出了山体外侧先开挖方案无论在围岩变形还是隧道结构受力方面相比于山体外侧后开挖都较小,安全系数相对较高。因此,合理的施工工序应该是先进行山体外侧开挖并施作初期支护,然后再在山体内侧开挖施工。
[Abstract]:Based on the construction of Liangcun Tunnel by CRD method, the deformation monitoring points and internal force test elements are set up in this paper. The deformation of surrounding rock and the structural internal force characteristics of the tunnel constructed by CRD method are analyzed. The excavation process of tunnel constructed by CRD method under different excavation sequence is simulated numerically, and the displacement and stress change of surrounding rock under different excavation sequence are analyzed and compared. The results show that the CRD method has a great influence on the construction procedure of different sections. The influence degree of each segment on the dome subsidence is one part, two parts, three parts and four parts, the inner wall rock pressure of tunnel is greater than that of the outside part, and the internal force of steel braces is compressive stress. The axial force in the arch waist position is greater than that in other parts. The difference of tunnel excavation deformation and the stress characteristics of the structure are compared, and the results of numerical analysis are combined. It is concluded that the first excavation scheme for the outside of the mountain body is smaller than that for the rear excavation of the mountain body in terms of the deformation of surrounding rock and the stress of tunnel structure, and the safety factor is relatively high. The reasonable construction procedure should be excavation outside the mountain body and initial support, and then excavation on the inner side of the mountain body.
【作者单位】：中南大学土木工程学院;
【基金】：国家自然科学基金资助项目(NO.51378514) 昆明市科技计划资助项目(2014-01-A-G-02-3049)
【分类号】：U455.4

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