岩溶区高速公路路堤及溶洞顶板稳定性数值分析

发布时间：2019-05-22 15:11

【摘要】：采用大型通用有限元软件ABAQUS对某室内模型试验进行了数值模拟,验证了三维有限元法进行洞室结构稳定性分析的可靠性。结合永武(永安-武平)高速公路A11合同段岩溶地质资料,将溶洞近似为与实际相近的椭球状,建立岩溶区路堤的三维有限元模型,分析溶洞顶板厚度、填方高度、溶洞位置以及溶洞充填状况对路堤及溶洞顶板稳定性的影响。为与现行顶板安全厚度确定方法进行比较,进行二维平面应变有限元分析。研究表明,对于较完整的顶板岩层,按顶板受拉破坏稳定安全系数为4确定的安全厚度过于保守,按梁板理论弯曲受拉破坏确定的安全厚度也偏于保守,是由于实际顶板岩层并不完全符合梁板理论的简化假设,而以有限元分析所得最大弯矩按梁板弯曲受拉破坏确定的安全厚度最为经济;实际工程中三维效应明显的溶洞,现行理论简化和二维数值分析法都较为粗糙,宜采用三维数值分析法。通过对上述问题的分析,为该高速公路岩溶区填方路段的设计和溶洞的处治与否提出指导性意见,已创造较好的经济效益和社会效益,可供类似工程应用时参考。
[Abstract]:The numerical simulation of an indoor model test is carried out by using the large-scale general finite element software ABAQUS, and the reliability of 3D finite element method for structural stability analysis of caverns is verified. Based on the Karst geological data of A11 contract section of Yongwu (Yongan-Wuping) Expressway, the cave is approximated to an ellipsoid shape similar to the actual one. The three-dimensional finite element model of embankment in Karst area is established, and the roof thickness and filling height of Karst Cave are analyzed. The influence of cave position and cave filling condition on the stability of embankment and cave roof. In order to compare with the current method for determining the safe thickness of roof, the finite element analysis of two-dimensional plane strain is carried out. The results show that for the more complete roof strata, the safety thickness determined by the stability safety factor of roof tensile failure is too conservative, and the safety thickness determined by bending tensile failure according to the theory of beam and plate is also conservative. The reason is that the actual roof strata do not fully conform to the simplified assumption of beam and plate theory, and the maximum bending moment obtained by finite element analysis is the most economical according to the safe thickness determined by the bending and tensile failure of beam and plate. For caverns with obvious three-dimensional effect in practical engineering, the current theoretical simplification and two-dimensional numerical analysis methods are rough, so it is appropriate to adopt three-dimensional numerical analysis method. Through the analysis of the above problems, this paper puts forward some guiding suggestions for the design of the filling section of the Karst area of the expressway and the treatment of the caverns, which has created better economic and social benefits, which can be used as a reference for the application of similar projects.
【作者单位】：福州大学岩土工程研究所;卧龙岗大学土木采矿与环境工程学院;福建省交通规划设计院;
【基金】：福建省交通规划设计院合作研究项目资助(No.2011J01308)
【分类号】：U416.12

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