The Research Of Force Chain Distribution Of Deep Foundation Pit Excavation Which Supported By Pile

Foundation pit excavation support is a complex project.Because of the uncertainty of the foundation pit itself,the excavation of the foundation pit is a systematic research project.Traditional research foundation,and is mainly for stability during excavation pit itself in the research,as well as rational,economic and other excavation of its surrounding environment.This method is mainly based on the classical earth pressure theory and the simulation method like Flac3 D.However,these methods are hold the soil as a continuous medium,if we hold the soil as a collection of particles and research the foundation pit project from the particle point of view will be helpful to the study of foundation pit engineering.According to the principle of similarity I to simulate the excavation by employing photo elastic test equipment that allows biaxial loading and bilateral particle flowing,from the change of the force chain,can reach a conclusion: In the process of pile foundation pit excavation,the change of force chains in the location of the foundation pit depth to the edge of foundation pit is the most intense.This means in the process of pile foundation pit excavation,the largest influence is on the distance between the support structure and the excavation depth.The force chains in the surrounding soil show a trend of increasing first and then decreasing,the results show that the influence of surrounding rock is a process of strengthening and weakening in the process of deep foundation pit excavation.Using discrete element software PFC to simulate the pile foundation pit excavation,By monitoring the force chain average value,and the horizontal and vertical displacement pile,and the horizontal distance of the supporting structure 0 meters,double the depth of excavation,two times the depth of excavation,the vertical distance from the ground 0 meters,5 meters,a distance of nine times the excavation force value chain change,we found that: The horizontal displacement vertical displacement of PFC simulation is consistent with the measured data,which indicates that PFC can reasonably simulate the deep foundation pit excavation.In the process of value chain force of foundation pit excavation is a process of first increased and then decreased,but after the excavation of the force chain average than the excavation before,that in the process of excavation impact on the surrounding environment is a first increased and then decreased,but the excavation is the impact on the surrounding stress is to increase the role of.Through the observation and the analysis of the excavation displacement field in the process of change,in the process of pit excavation,the displacement field is mainly concentrated in the horizontal direction at a distance of one times the depth of foundation pit supporting distance in the vertical direction on the ground at a distance of double supporting structure depth distance.Finally,the change of the position force chain is the most obvious in the excavation of the foundation pit,which is one of the excavation depth of the foundation pit.