正交各向异性非圆形水工隧洞的应力解析解

发布时间：2018-01-25 22:39

本文关键词： 隧道工程正交各向异性岩体非圆形隧洞内水压力应力解析解　出处：《岩石力学与工程学报》2017年S2期 　论文类型：期刊论文

【摘要】：为了探讨深埋正交各向异性水工隧洞的力学响应问题,考虑洞边作用均布内水压力的情况,基于平面弹性复变函数方法,推导任意孔形水工隧洞的应力解析解。推导中建立3套极坐标系,将物理平面孔外域映射到了像平面的单位圆外域,并建立孔边应力边界条件,再利用幂级数解法,求解出隧洞的应力场。以直墙半圆拱形隧洞为例,通过ANSYS数值计算对解析解进行对比验证,在此基础上,又运用解析方法研究马蹄形和圆形隧洞的孔边应力分布规律。研究结果表明:不同于各向同性岩体,隧洞的正交各向异性围岩应力场表现明显的非对称性;增大侧压力系数会使孔边的切向应力增加,但马蹄形隧洞2个曲率较大位置的切向应力却几乎保持不变;内水压力的增加能减小洞口的应力集中,曲率越大的位置减小越明显,但内水压力过大,会使孔边出现明显的拉应力,不利于隧洞的安全。
[Abstract]:In order to investigate the mechanical response of deep buried orthotropic hydraulic tunnel, considering the uniform internal water pressure of the edge of the tunnel, the plane elastic complex function method is used. Three sets of polar coordinate systems are established to map the physical plane plane outer domain to the unit circle outer domain of the image plane and the stress boundary condition of the hole edge is established. Then the stress field of the tunnel is solved by the power series method. Taking the semi-circular arch tunnel of the straight wall as an example, the analytical solution is compared and verified by ANSYS numerical calculation. The analytical method is also used to study the stress distribution of the borehole edge of horseshoe and circular tunnels. The results show that the stress field of the orthotropic surrounding rock of the tunnel shows obvious asymmetry unlike that of the isotropic rock mass. When the lateral pressure coefficient increases, the tangential stress of the hole edge increases, but the tangential stress at the two larger curvature positions of the horseshoe tunnel is almost unchanged. The increase of internal water pressure can reduce the stress concentration of the hole, and the greater the curvature is, the more obvious the position is, but if the internal water pressure is too large, there will be obvious tensile stress on the edge of the hole, which is not conducive to the safety of the tunnel.
【作者单位】：华北电力大学水电与岩土工程研究所;
【基金】：国家自然科学基金资助项目(11572126) 中央高校基本科研业务费(NCEPU2016XS55)~~
【分类号】：TV31;TV672.1
【正文快照】： 1 引言隧洞是水工建筑物引水系统的重要组成部分,隧洞开挖以后围岩中的应力变化和由此引起的围岩破坏一直是岩石力学研究和地下工程建设关注的问题。国内外很多学者在研究中都将隧洞围岩视为各向同性材料,对深埋隧洞的应力场进行了深入的研究[1-3]。但是B.Amadei[4]提出,在

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