Study On The Influence Of Pile Driving And Soil Squeezing Effect On Adjacent Subway Tunnel

Since the 21 st century,my country’s economy has developed rapidly and urbanization is expanding,which has also led to an increasingly tight urban space.Therefore,the development and utilization of underground space has become more and more common.In recent years,subway construction has been quite rapid and has gradually become a means of transportation for people’s daily travel.As of the end of2020,a total of 47 cities in China have opened subways,including 41 in Mainland China and 6 in Hong Kong,Macao and Taiwan.They are under construction and planning.There are countless subway lines in China,and there will inevitably be the construction of many adjacent subway lines.The construction of adjacent subway lines not only needs to manage the safety risks of the project itself,but also need to manage the safety risks caused by the interaction between the project and the existing lines.Pile foundation is one of the most common building foundations in engineering construction projects,and it has a long history from its birth to the present.Precast piles are now widely used due to their high construction efficiency and low environmental impact.However,precast piles are soil-squeezing piles,which will inevitably have an impact on surrounding structures,especially underground buildings.In the project that this article relies on,due to many pile-sinking constructions in the nearby site,the subway tunnel is displaced,and water leakage occurs locally.On this basis,this paper studies the phenomenon of pile driving and soil squeezing.At the same time,it provides reference materials for the study of the impact of similar engineering construction on the underground structure in the future,which has high research value and practicality.This paper mainly uses ABAQUS software to numerically simulate the process of pile sinking,and conducts an in-depth study of the pile-soil interaction,soil compression and deformation,and the impact on subway tunnels.The main research contents of this article include:(1)Collect and sort out the geographical environment and geological environment characteristics in the study area,and select effective parameters for the theoretical calculation and numerical analysis of pile driving and soil squeezing.(2)Perform theoretical calculations on the horizontal displacement and stress of the soil in the research site based on the theory of circular hole expansion.(3)The displacement loading method and the trigonometric function loading method were used to simulate the static pressure pile driving and the hammer driving pile driving under the condition of a single pile respectively,and the influence of soil squeezing under different pile driving methods was studied,and the numerical simulation calculation results were compared with the previous ones.The theoretical calculation results are compared and mutually verified.(4)Numerically simulate the pile-sinking process of the pile group,analyze the impact of soil squeezing under the action of the pile group,and use the method of comparative study to analyze the different effects of different pile-sinking sequences and whether stress relief holes are set on the subway tunnel.Researched.(5)Put forward suggestions to reduce the impact of pile sinking construction on underground structures.