Study On Stress Mechanism And Application For Round And Square Combined Cantilever Anti-slide Pile In The Fill Subgrade Project

Since the 13 th Five-Year Plan,the State has vigorously built basic public facilities such as roads and railways.And higher requirements for construction quality,schedules,costs,etc.In the construction of the project,problems such as slope management,subgrade filling,and excavation continue to emerge.Anti-sliding piles are one of the most common ways to solve such engineering problems.Traditional anti-sliding piles are manually digging into piles due to the large section size.This is a relatively backward construction process.Workers work hard,have low safety factors and lack safety guarantees.Therefore,a variable cross-section anti-slide pile emerged in some road embankments and slope retaining projects.The anchoring part is made of large-diameter mechanical holes and squared above the ground.In the engineering application,it is found that this variable cross-section anti-slide has more economic value and technical advantages than the conventional equal-section anti-slide pile.However,the related research on the deformation and bearing characteristics of the variable section anti-sliding piles lags behind the engineering practice.There are many engineering problems that need to be solved in the project,so the in-depth study of the system has a very important practical significance.In this paper,the mechanism of the new type of variable cross-section cantilever anti-sliding pile subjected to horizontal thrust load is analyzed and studied.By means of indoor model test,theoretical calculation and finite element analysis,the method is based on the Yunnan S25 Kunming to Qiaojia Expressway on A Subgrade Filling Project in Dongchuan-Gele Section Project.The main conclusions of this paper are as follows: Firstly,the stress distribution of the new cantilever type anti-sliding piles is uniform and there is no obvious stress concentration phenomenon.There is a stress diffusion angle at the position where the section of the pile changes,the stress is reasonable,and the utilization rate of the pile material is high;Second,the bending moment distribution of the conventional square equal-section anti-sliding pile is single-peak,and the maximum is located in the anchorage section.However,the bending moment of the new variable-section anti-slide pile is double-peaked,and the bending moment at the variable cross-section location The phenomenon of recovery occurs,which is the same as the change law of tension and pressure strain curves;Third,under the same level of force,compared with the traditional square anti-sliding piles,the anti-slide piles of the new variable-section anti-sliding piles move downwards,and they cannot be designed and checked in accordance with the conventional square section piles.Through the study of this paper,important innovations have been made in the pile bearing characteristics of such piles.The research results have important reference values for other variable cross-section structures and in engineering applications.