浅埋偏压隧道进洞施工力学特性研究

发布时间：2018-04-15 06:06

本文选题：浅埋隧道 + 软弱围岩　；参考：《地下空间与工程学报》2017年05期

【摘要】：隧道进口段围岩常常具有浅埋、偏压、风化严重等特点,若施工处理不当,极易造成洞口边、仰坡滑动和洞内塌方等事故,从而影响隧道正常施工和人员安全。结合具体工程,对浅埋偏压隧道进洞施工开展了三维数值模拟,并结合监测数据分析了施工对围岩和支护结构力学特性的影响,主要结论如下:围岩变形具有非对称性,浅埋侧围岩变形量要小于深埋侧;随着隧道的逐步开挖,隧道深埋侧拱脚和浅埋侧拱肩处围岩易于发生剪切破坏,而且围岩的塑性区也主要位于这两个区域,并逐渐向拱顶上方贯通;初期支护结构的受力状态受偏压地形影响显著呈非对称性,而超前支护受偏压影响较小;现场实测围岩变形与计算结果较为吻合,且变形在22天后达到稳定状态。
[Abstract]:The surrounding rock of the entrance section of the tunnel is often characterized by shallow burying, bias pressure and serious weathering. If the construction is not handled properly, it is easy to cause accidents such as the side of the tunnel, the sliding of the upside-slope and the collapse in the tunnel, thus affecting the normal construction of the tunnel and the safety of the personnel.Combined with the concrete project, the three-dimensional numerical simulation is carried out for the tunnel entry construction of shallow buried bias pressure tunnel, and the influence of construction on the mechanical properties of surrounding rock and supporting structure is analyzed in combination with monitoring data. The main conclusions are as follows: the deformation of surrounding rock is asymmetrical.With the gradual excavation of the tunnel, shear failure of the surrounding rock at the arch foot of the deep buried side and the arch shoulder of the shallow side of the tunnel is easy to occur, and the plastic zone of the surrounding rock is mainly located in these two regions, and the deformation of the surrounding rock in the shallow buried side is smaller than that in the deep side of the tunnel.The stress state of the initial supporting structure is asymmetrical significantly influenced by the deflection topography, while the advance support is less affected by the bias, and the deformation of the surrounding rock measured in the field is in good agreement with the calculated results.The deformation reached stable state after 22 days.
【作者单位】：同济大学道路与交通工程交通部重点试验室;中铁七局集团第二工程有限公司;
【基金】：国家自然科学基金(41130751) 中铁七局建设科技项目
【分类号】：U455

【相似文献】