Experimental Study On Engineering Behaviors Of Different Type Of Lateral Constrained Piles During Loading-Unloading Of Composite Foundation With Defective Pile

There are many forms of foundation treatment in soft soil area.The composite foundation treatment method has good economic benefit which is widely used in foundation treatment.The number of piles in the process of foundation engineering construction is increasing,which are difficult to be avoided defects such as broken pile and necking,and the defects are often caused by various defects due to various defects,and the defect rate is very large and the quantitative evaluation of engineering quality is difficult.The lateral piles can effectively suppress lateral displacement of composite foundation and lateral extrusion of soft soil,also reduce the settlement of composite foundation and improve the bearing and deformation characteristics of composite foundation.It is reasonable to use the lateral restraint piles to deal with the composite foundation with defective piles.And the lateral restraint pile is very complicated in the actual engineering work that the lateral deformation of the pile is caused by the bending deformation,the axial force and the lateral earth pressure cause some parts of the pile to be active pile,and the other parts for the passive pile,the work traits need to be further studied to guide the design and engineering practice.In this paper,the model test that according to the similarity theory for the current engineering problems is carried out with collecting the research progress domestic and abroad.The paper analyzes the engineering characteristics of the lateral restraining piles under the condition of connecting beams with different spacing between the friction piles and the rock-socketed piles and the piles,in the process of repeated loading and unloading,different types of lateral confinement pile top lateral migration,pile axial force,pile soil and pile side earth pressure,pile bending moment and pile side friction resistance distribution of comparative analysis.The results show that the lateral rock-socketed piles are better than those of the friction piles,and the effect of the piles on the piles is better.From the point of view of the force analysis of the pile,the pile foundation pressure,the pile side earth pressure,the pile bending moment and the pile side friction resistance are also increased and decreased,and the rock-socketed pile and the pile top are connected with each other.The overall bearing capacity of the beam and the effect of restraint are good.After repeated loading and unloading,the soil density is high,the carrying capacity of the composite foundation is strengthened,and the effect of the most lateral pile is smaller.The results of this study have a certain guiding effect on the design of lateral constrained pile with composite foundation with defective piles and the influence of composite foundation with defective piles on adjacent structures.