围岩空间变异性对隧道结构可靠度的影响分析

发布时间：2019-05-10 13:12

【摘要】：采用随机场模型能够有效地模拟围岩参数的空间变异性。文章将局部平均随机场理论、有限差分法和Monte-Carlo模拟结合在一起,得到了Monte-Carlo随机有限差分法,基于该方法编制了可考虑围岩空间变异性的隧道结构可靠度计算程序;并将围岩密度、弹性模量和内摩擦角等参数视为三维正态随机场,研究了围岩的竖向与水平向相关距离的变化对隧道结构可靠度的影响。计算结果表明,围岩空间变异性会显著影响隧道结构的可靠度,为了获得更为经济合理的支护方案,在支护设计时考虑围岩参数的空间变异性很有必要;围岩竖向或水平向相关距离的增大均会引起隧道结构失效概率的增加,但影响程度不同;隧道结构失效概率对围岩竖向空间变异性更加敏感,故在工程勘察费用较少时,可考虑将勘察费用更多地投入到竖向相关距离的勘测,水平向相关距离可参考已有经验数据取值。
[Abstract]:The random field model can effectively simulate the spatial variability of surrounding rock parameters. In this paper, the local average random field theory, finite difference method and Monte-Carlo simulation are combined to obtain the Monte-Carlo stochastic finite difference method. Based on this method, a reliability calculation program of tunnel structure considering the spatial variability of surrounding rock is compiled. The parameters such as surrounding rock density, elastic modulus and internal friction angle are regarded as three-dimensional normal random field, and the influence of the vertical and horizontal correlation distance of surrounding rock on the reliability of tunnel structure is studied. The calculation results show that the spatial variability of surrounding rock will significantly affect the reliability of tunnel structure. In order to obtain a more economical and reasonable support scheme, it is necessary to consider the spatial variability of surrounding rock parameters in support design. The increase of vertical or horizontal correlation distance of surrounding rock will increase the failure probability of tunnel structure, but the influence degree is different. The failure probability of tunnel structure is more sensitive to the vertical spatial variability of surrounding rock, so when the cost of engineering investigation is less, the investigation cost can be more invested in the survey of vertical correlation distance. The horizontal correlation distance can refer to the existing empirical data.
【作者单位】：同济大学地下建筑与工程系;安徽省综合交通研究院股份有限公司;
【基金】：国家自然科学基金项目(40772179,41072206) 贵州省交通厅科技项目(2010-122-010,013)
【分类号】：U451

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