The Damage Mechanism And Treatment Technique Of The Combination Of Widening Roadbed

Based on the Beijing-Shijiazhuang Expressway widening project, we studied thedisease mechanism of widening highway project by means of the old road testing,laboratory testing, theoretical analysis and numerical simulation in this paper. Finally westudied the corresponded treatment measures on the project.Specifically, the researchcontents include following parts:1)Through the site investigation and detection the old subgrade, including field testand indoor test,the old subgrade soil physical and mechanical parameters weresummarized;2) According to the field investigation of the old road, the numerical simulation of thedevelopment of stress and deformation of widening the subgrade using FLAC,weobtained the widening highway roadbed diseases occur mechanism;3) According to the mechanism of the subgrade widen occurred diseases, as well asthe domestic treatment subgrade widen, and method and measures according to thespecific circumstances of high-speed beijing-shijiazhuang, and put forward the suitable forthis engineering disease treatment measures, mainly by raising the roadbed compactiondegree, to the old road slope excavation on the steps and laid geogrid method, and adoptthe methods of theoretical analysis and numerical simulation.In addition, the degree of compaction of new and old roadbed constructionrequirements was analyzed theoretically in this paper.By the investigation of theengineering analysis, the theoretical calculations and numerical simulation, constructivecomments were proposed for Beijingstone high-speed widening project about its the oldroadbed quality assessment, site clean-up and clearing slope bench excavation, and theDitch handling and laid geotextile grille.