高速铁路采空区地基“活化”分级方法及工程应用

“Activation” classification method and its engineering application of high-speed railway subgrade in goaf area

随着我国高速铁路的快速发展,一些关键线路难免会穿越采空区场地,因此对于高速铁路选线等系列问题,采空区地基“活化”分级需要率先解决。以太焦高速铁路DK259+135.95-DK259+710.00线路段的下伏采空区为例,运用层次分析法和模糊数学的基本原理建立了高速铁路采空区地基“活化”分级评判模型。首先确定了影响高速铁路采空区地基“活化”分级的5个大因素、19个因子,在此基础上提出了高速铁路采空区地基“活化”分级因素影响度的划分标准,并组合各因素影响度,提出了相对应的高速铁路采空区地基“活化”分级标准;采用层次分析法确定了影响因素及评价因子的权重,并通过德菲尔法、模糊统计和隶属函数相结合得出了评价因子的隶属度;同时初步分析了高速铁路采空区地基“活化”分级的典型特征;最后运用模糊综合评价法对该段采空区地基进行了“活化”分级,并确定了该段采空区地基为“必活化”。该模型的分级结论符合现场的实际工况,并为后期该段采空区地基采用注浆法治理提供了理论依据。该段采空区地基注浆治理后,又对其进行了二次“活化”分级,确定了注浆治理后的高速铁路采空区地基为“不活化”,这为太焦高速铁路安全运营提供了一种科学、合理的新论证。

With the rapid development of China’s high-speed railway, some key lines will inevitably pass through the goaf site.Therefore, the “activation” classification of high-speed railway subgrade in goaf area needs to be solved first prior to a series of problems such as route selection of high-speed railway in goaf area. In this article, the underground goaf at the chainages DK259+135.95-DK259+710.00 of Taiyuan-Jiaozuo high-speed railway is taken as an example. A classification and evaluation model for "activation" of high-speed railway subgrade in goaf area is established using the basic principles of analytic hierarchy process and fuzzy mathematics. Firstly, five major factors and nineteen sub-factors affecting the classification of high-speed railway subgrade in goaf area are determined. On this basis, the classification standard of influence degree for “activation” classification factors of high-speed railway subgrade in goaf area is proposed, and the corresponding classification standard of “activation” of high-speed railway subgrade in goaf area is obtained by combining the influence degree of each major factor. By adopting the analytic hierarchy process, the weights of influencing factors and evaluation factors are determined, and the membership degrees of evaluation factors are obtained in combination with Delphi method, fuzzy statistics and membership function. Meanwhile, the typical characteristics of “activation” classification of high-speed railway subgrade in goaf area are preliminarily examined. Finally, the “activation”classification of the railway subgrade in goaf area is carried out using fuzzy comprehensive evaluation method, and the subgrade in this project is determined to be “necessarily activated”. The classification conclusion of the model is in line with the actual working conditions of the site, which provides a guiding significance for the later treatment of the subgrade in goaf area by grouting. After grouting treatment for the goaf area, another “activation” classification is carried out, and the subgrade in this project is determined to be “inactive”, which provides a scientific and reasonable demonstration for the safe operation of Taiyuan-Jiaozuo high-speed railway.