Stability Analysis Of Circular Foundation Pit Based On Strength Reduction Technique

The space arching effect is an undeniable advantage of the circular diaphragm wall which promotes the wide application of circular foundation pit and diaphragm wall in Engineering Building,an increasing number of construction projects have chosen to use circular foundation pits and underground continuous walls.The existence of space arching effect of circular foundation pit is of great significance to the stability of foundation pit,many scholars have analyzed and studied the space arching effect of circular foundation pit.Based on the three-dimensional modeling and analysis of numerical simulation software of rock and soil,the simulation results are in good agreement with the actual monitoring data.Demonstrate the feasibility of three-dimensional Simulation Analysis.The space arching effect and influencing factors of the circular underground continuous wall are analyzed by numerical simulation software.In the study of the strength reduction method to solve the safety coefficient,the influence of the inner diameter of the foundation pit,the depth of the wall,the internal friction angle and the cohesive force of the soil were analyzed.The simulation results show that soil pressure on the outside of the diaphragm wall and the circumferential pressure of the circular enclosure are balanced by the space arching effect,it is helpful to reduce the lateral deformation of the circular diaphragm wall and reduce the uplift at the bottom of the pit,it is helpful to maintain the stability of foundation pit.The results of the influence factors show that the arch effect is influenced by the depth ratio of the foundation pit diameter,the wall stiffness,the thickness of the wall and the supporting parameters of the lining.The depth ratio of foundation pit is the main factor,the relationship between the arching effect and inner diameter is nonlinear.Because of the restriction of the arching effect,it is difficult to influence the whole stability of foundation pit by changing the parameters of wall and lining,the correlation sensitivity with the arching effect of the foundation pit is much less than the inner diameter of the foundation pit.