基于Hoek-Brown准则西原模型的圆形隧洞黏弹塑性解

发布时间：2018-03-05 20:14

本文选题：黏弹塑性　切入点：西原模型　出处：《水利水电技术》2017年04期 　论文类型：期刊论文

【摘要】：为进行流变围岩圆形隧洞工程应力、应变分析,将Hoek-Brown强度准则引入到西原流变本构模型,同时在力学模型中考虑掌子面推进效应和支护阻力对围岩应力释放率的影响,得到了支护条件下基于Hoek-Brown准则西原模型的圆形隧洞黏弹塑性解。通过锦屏二级水电站引水隧洞案例验证解析方法的可靠性,并进行了塑性区半径和围岩变形的影响因素定量分析。研究结果表明:(1)基于Hoek-Brown准则的西原模型更能反映实际隧洞工程岩体流变特性,建立的解析方法能够考虑围岩应力释放效应和塑性体积扩容特征对围岩变形的影响,其计算结果与实际监测数据吻合良好;(2)围岩应力释放系数、Hoek-Brown准则参数s、原岩应力和隧洞半径对塑性区半径的影响较大,是判断流变围岩隧洞稳定性的主要考虑指标,相对而言,岩石单轴抗压强度和Hoek-Brown准则参数m对塑性区半径的影响较小;(3)引入围岩扩容系数后,围岩位移量显著增加,但基本不影响围岩流变变形曲线形态和塑性区半径,从洞壁向围岩内部延伸,围岩扩容系数对围岩变形的影响越来越小。
[Abstract]:In order to analyze the stress and strain of rheological surrounding rock circular tunnel engineering, the Hoek-Brown strength criterion is introduced into the western-original rheological constitutive model, and the influence of the propelling effect of face surface and supporting resistance on the stress release rate of surrounding rock is considered in the mechanical model. The viscoelastic-plastic solution of circular tunnel based on the Hoek-Brown criterion is obtained under the support condition. The reliability of the analytical method is verified by the case of the diversion tunnel of Jinping II Hydropower Station. The quantitative analysis of the influencing factors of the radius of plastic zone and the deformation of surrounding rock is carried out. The results show that the Xiyuan model based on Hoek-Brown criterion can better reflect the rheological characteristics of rock mass in actual tunnel engineering. The analytical method can take into account the stress release effect of surrounding rock and the effect of plastic volume expansion on the deformation of surrounding rock. The calculated results are in good agreement with the actual monitoring data.) the stress release coefficient of surrounding rock and the parameter of Hoek-Brown criterion s, the original rock stress and the radius of tunnel have a great influence on the radius of plastic zone, which is the main consideration index to judge the stability of rheological surrounding rock tunnel. The uniaxial compressive strength of rock and the influence of Hoek-Brown criterion parameter m on the radius of plastic zone are small.) when the expansion coefficient of surrounding rock is introduced, the displacement of surrounding rock increases significantly, but it does not affect the shape of rheological deformation curve and the radius of plastic zone. From the wall of the tunnel to the interior of the surrounding rock, the influence of the expansion coefficient of the surrounding rock on the deformation of the surrounding rock is becoming smaller and smaller.
【作者单位】：中国水利水电科学研究院流域水循环模拟与调控国家重点实验室;北京交通大学土木建筑工程学院;
【基金】：国家重点研发计划课题(2016YFC0401801,2016YFC0401804) 中铁第一勘察设计院项目基金资助(2014-93-08-01)
【分类号】：TV554

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