Application Research And Numerical Analysis Of High-rise Building Rectification And Reinforcement Technology

In this paper,based on the uneven settlement accident of a pile foundation high-rise building,the reasons for the inclination of the building and the proposed method of “pile end unloading method + patch reinforcement + supplementary raft” are described and analyzed.The method is a three-dimensional numerical simulation of the interaction of the superstructure,foundation and foundation soil.The main research results are as follows:(1)On the basis of considering the eccentric bending moment,the newly added artificial digging piles make the reaction center of the pile foundation as a whole match the quality center of the upper structure,which can promote the building to lean back and consolidate.The purpose of the superstructure is safe.(2)During the unloading process of the pile end,the settlement of the soil generated by the unloading of the previous batch is always smaller than the settlement caused by the subsequent unloading.The soil disturbance during the unloading period has little effect on the foundation soil,and the settlement effect is not obvious.As the pile end unloading proceeds in sequence,the rectification effect of the building becomes more and more significant with the unloading.(3)At the initial stage of unloading of the pile end,unloading of the pile with less load on the intermediate intermediate position is beneficial to control the initial foundation settlement.As the unloading is carried out in sequence,the partial unloading has the greatest influence on the adjacent piles,and the influence on the piles is small.In the process,the bearing capacity of the adjacent piles should be checked in time,and the adjacent piles should be strengthened and strengthened.The most significant unloading effect is the pile position along the north-south direction(inclined direction).In the process of rectification,the longitudinal displacement(vertical to the deflection direction)can be used to unload the pile position,and the settlement is conservatively observed,and then the lateral position(parallel to the deflection direction)unloads the pile to control the settlement effect.(3)After the connection between the foundation beam and the newly-protected pile is completed,the vertical compressive stress of the intermediate beam is relatively large,and the maximum stress value of the poured slab is significantly reduced,and the stress distribution between the regions is also uniform.The overall settlement of the raft is distributed in a "concave" shape.The north side of the middle part is more settled than the south side,and the east-west differential deformation is more deformed than the north-south side.(4)The pile beam has a great influence on the pile at the position of the axis,and the pile-bearing structure increases the force range of the pile foundation.It is necessary to strengthen the pile along the axial position to prevent Exceeding the ultimate bearing capacity of the pile.The new pile has obvious load shedding effect on the overall pile foundation.After the pouring of the rafts,the overall stress of the foundation has been transferred to a certain extent,and the stress of each pile is relatively uniform,realizing the redistribution of the load between piles and piles,and coordinating the change of stress between piles and soils,indicating that the rafts are It is very good to distribute the concentrated load.(5)The project was optimized by finite element simulation analysis,and the reasonable thickness in the slab construction was analyzed,and the whole pile raft foundation was optimized.In order to control the uniform reaction force of each pile,the angle pile and the side pile reversed.The difference between the force and the internal pile can effectively achieve the purpose of rectification and reinforcement in the design of the new pile layout with the "inside and outer dense" as the method of filling the pile.