Application Of Vacuum Combined Surcharge Preloading Method For Railway Foundation Improvement

The rapid development of economy has brought great challenges to the construction of infrastructure.In recent years,the construction of railway engineering has developed rapidly,and it has important theoretical significance and application value to study the practical effect of vacuum-surcharge combined preloading on soft soil foundation.Chinese eastern coastal areas are widely distributed with soft soil foundation,in the soft soil foundation to build the railway,must strictly control the roadbed settlement.The control of roadbed settlement is the most important task to ensure the safe and efficient operation of railway.The results show that the vacuum-surcharge combined preloading method can effectively accelerate the settlement rate of soft soil foundation,shorten the construction period and reduce the post-construction settlement.At the same time,it can effectively reduce the lateral deformation of the roadbed and improve the stability of the roadbed.Vacuum-surcharge combined preloading method has obvious advantages in terms of cost,duration and environmental protection,especially the effect of traditional soft soil foundation treatment,and is widely used in the treatment of soft soil roadbed of road engineering.In this paper,based on the previous study,combined with a railway vacuum-surcharge combined preloading soft foundation treatment project,using theoretical analysis,on-site monitoring and numerical simulation of the combination of vacuum-Construction of the railway in the strengthening mechanism of the foundation,soil properties and reinforcement effects were explored.For the vacuum-stacking combined preloading method,according to the practical application of the following work:(1)Summarize the research results of the existing drainage consolidation method,analyzes the mechanism of the soft preloading method and the softening method of the soft soil by the preloading method from the consolidation theory.The vacuum-mechanism and consolidation characteristics of the soil foundation are studied systematically,and the changes of the particles in the soil are analyzed from the microscopic point of view.(2)Through field monitoring,the distribution and variation of parameters such as foundation settlement and horizontal displacement under vacuum preloading are obtained.Based on the analysis of geological conditions and working conditions,the deformation law of soft soil under the combination of vacuum and surcharge is studied,In order to show the effect of vacuum-surcharge combined preloading method on soft soil foundation reinforcement.(3)Based on the finite element method and the characteristics of engineering stratum,the consolidation model of soft soil foundation is established.By simulating the consolidation method and foundation deformation process of the foundation soil in the vacuum preloading process,the vacuum-The practicality and high efficiency of soft soil foundation strengthened by combined preloading method.(4)Compare the finite element calculation value with the measured value to verify the accuracy of the model selection and the simplified method,and provide reference for the optimization design of the soft soil foundation reinforcement project similar to the vacuumsurcharge preloading method to improve the construction efficiency and Reduce the project cost,and provide guidance for predicting the effect of foundation reinforcement under similar geological conditions.