深埋水工圆形隧洞塑性位移三剪统一解

发布时间：2018-04-01 05:33

本文选题：深埋水工圆形隧洞　切入点：中间主应力　出处：《建筑科学与工程学报》2017年06期

【摘要】：基于三剪统一强度准则和弹脆塑性模型,考虑中间主应力、渗流、剪胀、软化和塑性区弹性模量等因素的影响,推导了含有5种因素综合影响的水工圆形隧洞塑性区位移解析解;通过算例分析,得出了各参数对隧洞塑性区位移的影响规律。结果表明:各参数取不同值时,位移解可退化为一系列解,参数值可根据具体工程进行合理选择,具有广泛的适用性;围岩剪胀特性对隧洞塑性区位移的影响显著,若不考虑其影响,将明显低估隧洞的变形以致工程设计偏于危险;考虑中间主应力的影响能发挥围岩的强度潜能,减少支护,节约工程造价;考虑渗流和软化特性对隧洞塑性区半径的影响可使塑性区范围更接近围岩真实的变形范围;塑性区弹性模量采用含有半径幂函数的表达式可充分考虑围岩受扰劣化后的应力重分布及爆破损伤等影响,更符合隧洞真实变形情况;该位移解为隧洞塑性区位移计算提供了理论依据,对工程设计有一定的参考价值。
[Abstract]:Based on the three shear unified strength criterion and elastic-brittle plastic model, the effects of intermediate principal stress, seepage, shear expansion, softening and elastic modulus of plastic zone are considered. The analytical solution of displacement in plastic zone of hydraulic circular tunnel with five factors is deduced, and the influence of each parameter on displacement of plastic zone of tunnel is obtained by example analysis. The results show that when the parameters are different, The displacement solution can be degenerated into a series of solutions, and the parameter values can be reasonably selected according to the specific project, which has wide applicability, and the shear dilatancy of surrounding rock has a significant effect on the displacement in the plastic zone of the tunnel, if the influence is not taken into account, The deformation of the tunnel is obviously underestimated and the engineering design is inclined to be dangerous, and the strength potential of the surrounding rock can be brought into play by considering the influence of the intermediate principal stress, and the support can be reduced and the engineering cost can be saved. Considering the influence of seepage and softening characteristics on the radius of plastic zone of tunnel, the range of plastic zone is closer to the real deformation range of surrounding rock. The expression of elastic modulus in plastic zone with radius power function can fully consider the stress redistribution and blasting damage of surrounding rock after disturbance and deterioration, which is more in line with the true deformation of tunnel. The displacement solution provides a theoretical basis for the calculation of the displacement in the plastic zone of the tunnel, and has a certain reference value for the engineering design.
【作者单位】：长安大学建筑工程学院;
【基金】：国家自然科学基金项目(51508028,41202191) 中国博士后科学基金项目(2016T90879,2014M562357) 中央高校基本科研业务费专项资金项目(310828173402)
【分类号】：TV672.1

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