统一强度理论下非均匀应力隧洞围岩抗力系数

发布时间：2018-10-23 08:41

【摘要】：基于统一强度理论,合理考虑了围岩的中间主应力和剪胀特性的影响,采用岩石材料的弹塑性模型和非关联线性流动法则,通过引入地应力侧压力系数λ,推导了非均匀应力场下圆形隧洞围岩抗力系数的通用计算公式。由于统一强度理论具有明确的物理意义和广泛的适用性,而侧压力系数的引入能更好地描述隧洞开挖后围岩所处的真实应力状态,因此推导出的抗力系数公式具有更广泛的意义。最后通过实例分析了围岩抗力系数与侧压力系数λ、极轴夹角θ和剪胀系数h之间的关系。分析表明:随着侧压力系数和剪胀系数的增大,围岩抗力系数逐渐减小,隧洞不同位置处围岩抗力系数也不相同,在隧洞两侧,围岩抗力系数值最大,在拱顶和拱底处最小。
[Abstract]:Based on the unified strength theory, the influence of the intermediate principal stress and shear dilatancy of surrounding rock is reasonably considered, and the elastic-plastic model of rock material and the non-correlated linear flow rule are adopted. By introducing the coefficient of in-situ stress and lateral pressure 位, a general formula for calculating the resistance coefficient of surrounding rock of circular tunnel under inhomogeneous stress field is derived. Because the unified strength theory has clear physical meaning and wide applicability, the introduction of lateral pressure coefficient can better describe the real stress state of surrounding rock after tunnel excavation. Therefore, the derived formula of resistance coefficient has more extensive significance. Finally, the relationships between resistance coefficient of surrounding rock and lateral pressure coefficient 位, polar axis angle 胃 and shear expansion coefficient h are analyzed by examples. The analysis shows that with the increase of lateral pressure coefficient and shear expansion coefficient, the resistance coefficient of surrounding rock decreases gradually, and the resistance coefficient of surrounding rock is different at different positions of tunnel. The resistance coefficient of surrounding rock is the largest on both sides of tunnel, and the smallest at arch top and arch bottom.
【作者单位】：中国地质大学(武汉)工程学院岩土钻掘与防护教育部工程研究中心;
【基金】：湖北省自然科学基金(2013CFA110) 中国地质大学(武汉)教学实验室开放基金(SKJ2013107)资助
【分类号】：U452.12

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