ISSN 1000-3665 CN 11-2202/P

    非均布路基荷载下溶洞顶板稳定性分析

    Stability analysis of the karst roof under the non-uniform subgrade load

    • 摘要: 基于Boussinesq解求得在非均布路基荷载作用下溶洞顶板上的附加应力,利用MATLAB采用高阶次函数拟合顶板上附加应力的分布形式;将计算结果与上覆土层和顶板的自重作用相叠加,得到溶洞顶板分别按简支梁、固支梁和悬臂梁计算时的最大弯矩和最大剪力;进而,通过对溶洞顶板最大拉应力和最大剪应力的计算,用以判定溶洞顶板抗弯和抗剪切的稳定性,从而提出一种非均布路基荷载下溶洞顶板的稳定性评价方法。最后,引入稳定系数,从路基荷载的分布形式、溶洞与路基荷载的相对位置、溶洞顶板的厚度以及顶板跨径四个方面进行参数分析;并通过工程算例对比分析,验证本文方法的可行性和合理性。

       

      Abstract: According to the Boussinesq solution, the additional stress on the karst roof under the non-uniform subgrade load is obtained. The MATLAB is used to fit the distribution of the additional stress on the roof with a high order function. The maximum bending moment and shearing force of the karst roof that is treated as a simply supported beam, fixed beam and cantilever beam are obtained by superimposing the calculated results with the self-weight effect of the soil and the roof. The bending and shearing stability of the roof is determined by calculating the maximum tensile stress and shear stress on the karst roof, and a stability assessment method of the karst roof under the uneven embankment load is put forward. The stability factor is introduced to carry out the parameter analysis from four aspects: the distribution of subgrade load, the relative position of the cave and the subgrade load, the thickness of the roof, and the span of the roof. The feasibility and rationality of the method are verified with the comparative analysis of the engineering example.

       

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