导洞超前开挖施工性态空间效应分析

发布时间：2018-06-19 01:06

本文选题：隧道工程 + 导洞超前开挖　；参考：《岩石力学与工程学报》2014年S1期

【摘要】：围岩变形机制及稳定性控制是隧道施工过程中关键技术之一。针对导洞超前开挖施工性态空间效应,采用有限差分软件FLAC3D模拟分析隧道施工过程中围岩变形规律,并与全断面法、上下台阶法作对比分析。研究表明:导洞超前开挖施工引起的水平收敛、拱顶沉降位移变化速率最小,开挖形成临空面之后产生的水平收敛和拱顶沉降值最小,有利于隧道围岩的稳定;水平收敛值随隧道埋深、侧压力系数的增大呈线性增大;拱顶沉降值随埋深的增大呈线性增大,随侧压力系数的增大呈非线性增大趋势;隧道埋深越大,水平收敛、拱顶沉降先行位移占总位移比例越大;侧压力系数越大,水平收敛先行位移所占比例越大,而拱顶沉降先行位移所占比例越小。结合宜巴(宜昌至巴东)高速公路石门垭隧道施工现场监测数据,验证所得结论的可靠性,可为同类工程借鉴,具有一定的科学意义和工程实用价值。
[Abstract]:Deformation mechanism and stability control of surrounding rock is one of the key techniques in tunnel construction. In view of the spatial effect of leading excavation in tunnel construction, the deformation law of surrounding rock during tunnel construction is simulated by finite difference software FLAC3D, and compared with the full section method and the upper and lower step method. The research shows that the horizontal convergence caused by the ahead excavation of the guide tunnel, the minimum rate of change of the settlement displacement of the arch roof, the minimum horizontal convergence and the minimum value of the settlement of the arch after the formation of the face near the empty surface are beneficial to the stability of the surrounding rock of the tunnel. The horizontal convergence value increases linearly with the depth of the tunnel, the settlement value of the arch increases linearly with the increase of the buried depth, and with the increase of the lateral pressure coefficient, the horizontal convergence of the tunnel increases with the increase of the buried depth. The greater the proportion of the first displacement to the total displacement is, the greater the lateral pressure coefficient is, the larger the proportion of the horizontal convergence advance displacement is, and the smaller the proportion of the first displacement of the dome settlement is. Combined with the site monitoring data of Shimenya tunnel of Yi-ba (Yi-ba to Badong) expressway, the reliability of the conclusions obtained can be used for reference for similar projects, which has certain scientific significance and engineering practical value.
【作者单位】：山东大学岩土与结构工程研究中心;中国矿业大学深部岩土力学与地下工程国家重点实验室;
【基金】：国家重点基础研究发展计划(973)项目(2013CB036000) 山东大学自主创新基金(2012TS064) 中国矿业大学深部岩土力学与地下工程国家重点实验室开放基金项目(SKLGDUEK1105)
【分类号】：U451.2

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