Study On Generalized Replacement Technology Of Soft Soil Subgrade Of Highway In Mountainous Area

With the development of highway network construction in China,the key areas of highway construction in recent years have changed from plain and micro hill areas to areas with a wide range of hills and landforms.It is inevitable to encounter a large number of weak subgrade sections in the form of subgrade when constructing expressway in hilly areas.The theoretical research results and practical experience obtained in the previous engineering projects have been unable to fully meet the needs of soft soil subgrade treatment in mountainous areas.In addition,how to make full use of cutting excavation stone or other quarried stone,reduce the amount of subgrade filling and excavation,and perform the values of green highway construction has become an urgent problem in subgrade construction.This paper starts with the optimization of soft soil subgrade replacement technology in the mountainous area,through the study of the existing form of soft soil and the characteristics of topography and geomorphology in the mountainous area,puts forward the generalized replacement technology suitable for the replacement treatment of soft soil subgrade in the mountainous area,demonstrates its technical feasibility,and makes a comparative analysis of its economic rationality in combination with the supporting projects.Finally completed the following research work.(1)Based on the study of the existing form of soft soil and the characteristics of topography and geomorphology,combined with the relative position of embankment and soft soil,a set of classification method of soft soil in mountainous area is formed.(2)Based on the principle of fine design,construction and management,improving economic benefits and reducing waste of non renewable resources,the influencing factors of generalized replacement treatment method and method selection are summarized.(3)The feasibility demonstration of various generalized replacement methods is completed,and the applicable scope of generalized replacement methods in different cases is summarized,forming a set of generalized replacement construction technology and quality control method.(4)According to the construction characteristics of the mountain area,the feasibility of the generalized replacement treatment technology is verified by collecting and recording the relevant data of the generalized replacement treatment method(clearing and filling,overall replacement,partial replacement,replacement + mud squeezing,etc.)through the field test.The economic comparison analysis shows that the technology has good economic value.Through the above research work,it is proved that the generalized replacement technology of comprehensive clearing and filling,overall replacement,partial replacement,replacement +squeezing silt and other treatment methods has widened the scope of replacement and filling treatment of soft soil subgrade and the source of filler,which can effectively reduce the project cost,reduce the damage of the natural environment caused by the project construction,and has good promotion and application value.It is hoped that this paper will provide a new idea for similar projects,and promote the progress of soft soil subgrade treatment technology in mountainous areas.