Study On Treatment Technology And Application Of Vacuum Combinedsurcharge Preloading Soft Foundation

Since 1980s,China has a vast territory,rapid development of expressway,wide distribution of soft foundation.At present,there are many soft foundation treatment technologies,some methods are not economical,time-consuming,labor-consuming and safety hidden dangers.The soft foundation tlreatment technology is also developing continuously.The large area soft foundation treatment technology,which is more economical,efficient and adaptable,is the vacuum combined surcharge preloading method.Throughout the development trend of expressway in our country,this method has a wide range of applications.Therefore,the main content of this paper is the reinforcement mechanism and construction technology of vacuum combined surcharge preloading method..First of all,this paper expounds the course and present situation of highway construction in China,finds out the problems that perplexed highway construction,and introduces a variety of soft foundation treatment methods.On this basis,the development history and research status of vacuum combined surcharge preloading method are described..Secondly,the research status of vacuum combined surcharge preloading method is reviewed,the stress distribution and deformation law of foundation treated by vacuum combined surcharge preloading method are analyzed,and the action mechanism of vacuum combined surcharge preloading method is studied.Based on the technical analysis of vacuum combined surcharge preloading method,the improvement direction is put forward.Through the comparative analysis of concrete engineering examples,the characteristics and advantages of vacuum combined surcharge preloading method for strengthening soft foundation are expounded.At the same time,on the basis of vacuum combined surcharge preloading method,the formulas for calculating the consolidation degree of three-dimensional sand well consolidated foundation and sand well not penetrating through the whole compressed layer foundation are derived.based on the idea of back analysis of consolidation coefficient,the soft foundation is obtained.The prediction formula of foundation subsidence is used to guide the actual engineering construction.The correctness and rationality of the method are verified by an engineering example.