The Research Of Stability Analysis And Treatment Method On Underlying Karst Area Of Lou-Xin Highway

ABSTRACT:With the development of highway construction, more and more karst areas have been explored, the stability and the deformation development of karst ground have become prominent issues in engineering construction. How to improve the safety and reliability of basic highway treatment in karst areas has become a new topic of the foundation treatment. This paper summarizes the distribution rules of karst areas under the highway and the impact analysis of the roadbed construction on karst foundation. Based on that, the stability and the minimum safe thickness of karst roof in highway roadbed are analyzed by means of stochastic medium theory,several treatment schemes proposed for Karst segment are compared. After the analysis, the treatment scheme of "dynamic compaction+partical grouting+double reinforced concrete continuous slabs" is decided to adopt and the corresponding suggestions are put forward.Details are as follows:1. The forming conditions of Karst under the louxin highway and the distribution rules of various karst forms in karst areas is elaborated2. The movement and the deformation characteristics of roadbed in karst areas and the influence depth of roadbed construction on karst are studied3. The stochastic medium theory is used to deduce the displacement and deformation formula of the surface and rock and soil mass induced by the karst collapse, the minimum safe thickness of karst roof is determined.4. The structure of the karst cover plate is designed and calculated according to the specification, and the stress distributions and deformation characteristics of the cover plate and the foundation under the action of roadbed filling materials are obtained by numerical calculation.5. The engineering geological information of the K30+882.47～K31+380karst segment of louxin highway is investigated on the spot and analyzed. Through the comparison of karst ground treatment schemes,the treatment scheme of "dynamic compaction+partical grouting+double reinforced concrete continuous slabs" is put forward and the main parameters of dynamic compaction and pilot test is designed, and the experiment of dynamic consolidation is designed.