Research On Application Of Lateral Restraint Pile In Rectification And Reinforcement Of Existing Buildings

The rectification and reinforcement of high-rise building is a complex work with high technical difficulty,high risk and comprehensive.Once the corrective measures are out of control or the reinforcement measures are improper,it is difficult to prevent them from continuing to tilt,and the inclination is acceleration,and the consequences will be disastrous.In order to prevent the building from settling in the course of rectification,the change of the settlement and the inclination occur again after the rectification,ensure the results of rectification and long-term stability of buildings,it is necessary to take reinforcement measures to ensure the controllability of the rectification process,and it is an effective method to set the lateral restraint piles around the foundation.When the foundation is corrected,it will cause disturbances,so the anti-tilting reinforcement is the key to ensure the safe use of the building in the future.The safety and reliability of the building will directly affect the normal use of the building.Therefore,it is necessary to study the application of the lateral restraint pile in the rectification and reinforcement of existing buildings.The research contents and corresponding research results of this paper mainly include the following two aspects:(1)This paper designs the indoor model test combined with a high-rise building,and studies the bearing capacity of the foundation,the magnitude and distribution of additional stress in soil,the mechanical behavior of the lateral restraint pile before and after the pile layout.In addition,the response of foundation soil under different loading methods was also studied.The finite element analysis software ABAQUS is used to simulate the laboratory test.The influence of the lateral restraint pile on the behavior of the foundation soil is analyzed and verified.Considering the interaction of soil and pile,the influence of the length of pile,the distance from the foundation edge and the modulus ratio of pile to soil on the settlement of the foundation and the lateral displacement of the pile body are analyzed.It also gives a brief introduction to the concrete example of the lateral restraint pile,and analyzes the actual force characteristics of the foundation soil and the lateral restraint pile by numerical simulation,and optimizes the original design scheme.(2)Under the same vertical load,the settlement of foundation with the reinforcement of the lateral restraint pile is obviously lower than that of unconfined foundation,and the bearing capacity of foundation is about 40% higher than that ofunconfined piles.Taking the eigenvalue of foundation bearing capacity as a boundary,the pile bending moment at different depths increases with the increase of load and the phenomenon of reverse growth locally.The soil pressure on the eccentric side will be concentrated to the piles ahead of time.The plastic deformation in the soil and its influence area will increase with the increase of the load level.Under the eccentric load,the bending moments of pile body all increased greatly and tended to decrease.It is found that the length of pile,the distance from the foundation edge and the modulus ratio of pile to soil have an impact on the foundation settlement and lateral displacement of the pile.When the value is greater than a certain critical value,changing the design parameters of the lateral restraint pile has little effect.When using the method of basement floor slab to rectify and force the inclined structures,the horizontal displacement in the soil is mainly concentrated in the inner side of the lateral restraint pile.As the amount of the earth-dig is increased,the displacement is also increasing.The stress distribution of the lateral restraint pile is mainly concentrated in the upper and lower parts,and the stress in the upper part is obviously larger than the stress in the lower part.The stress in the southeast part is greater than the stress in other parts.