Analysis And Application Of Coordinated Settlement Of Foundation-Foundation-Superstructure On A Large Chassis

As the number of building floors continues to increase,more and more buildings choose to use complex foundations,foundations and superstructure combinations,such as natural foundations,anti-floating piles or anti-floating anchors,pile foundations and other foundations under the same floor And the basic form,at the same time the superstructure form is also very different.For this reason,it is very important to accurately analyze the settlement and deformation of buildings,and the analysis method that takes into account the synergy of foundation-foundation-superstructure is increasingly important.In the traditional single building,in the process of analyzing the stress and deformation of the building structure,it is generally divided into the upper structure,the foundation and the foundation to be analyzed separately.The existing method of solving the structure deformation is generally calculated for each part separately,and then combined to obtain The total deformation of the structure.However,when using this solution method to calculate the existence of multiple building structures of different heights on the large chassis,the calculation results will not match the actual deformation due to the neglect of the synergy between the structure and the foundation,and as the load difference of different buildings increases,The calculation deviation will be very large.In response to this problem,many scholars have continued to carry out research on collaborative settlement analysis methods of foundationfoundation-superstructure,and carried out more improvements and optimizations of collaborative analysis calculation methods.Collaborative analysis highly relies on the computing power of computers.With the continuous improvement of finite element numerical simulation software,the collaborative design and analysis of large and complex structures has become a mainstream method.This paper relies on the collaborative analysis of the settlement of multiple buildings on the large chassis of the A21 block of Beijing Future Science and Technology City,and explores the application of the collaborative settlement analysis results in the optimization of geotechnical engineering design.The work conclusions are as follows:1.Using the foundation-foundation-superstructure collaborative settlement analysis method,the stiffness of the superstructure and the foundation slab is used as the main factor to analyze the coordinated deformation of the structure,using reliable regional empirical soil constitutive models and settlement observation data,using large-scale Finite element software can more accurately calculate and predict the deformation of building foundations and foundations,and its calculation and analysis results can assist in optimizing the design of the foundation structure,determining the time for pouring of the post-pouring zone,and determining the time to stop the precipitation.2.When the foundation settlement prediction and the CFG pile composite foundation design are carried out,when the post-pouring zone is divided into blocks and the layered sum method specified in the specification is used to calculate and solve,the change in the stress distribution and settlement of the upper load due to the stiffness of the basement floor is not considered The synergistic effect will cause the settlement calculation results to be generally too large;the use of finite element software to analyze the calculation results of the coordinated settlement of different load structures on the large chassis can effectively optimize the design scheme of the CFG pile composite foundation.3.Through coordinated settlement calculation of the upper,middle and lower parts of the upper structure,foundation,and foundation on the large chassis foundation,the settlement prediction of the entire foundation raft can be realized,and the settlement deformation degree of each area can be accurately displayed.The finite element coordinated settlement calculation of this project verified the rationality of the foundation scheme design of the sub-building calculation in the structural design,indicating that the settlement control plan formulated by the project is feasible under the condition of considering the synergy of foundation-foundationsuperstructure.4.Calculate the settlement difference on both sides of the post-pouring zone through a variety of methods for different conditions such as single body and whole.According to the normative method,it is compared with the analysis result of the coordinated settlement of the foundation-foundation-superstructure on the large chassis,and the design raft can withstand Maximum differential deformation,analysis of the changing trend of the measured data of building loading and settlement,and the principle of the pouring time of the post-pouring zone are determined;on this basis,combined with the short-term water level prediction of the site,an optimal judgment method for the time node of stopping the project's precipitation is given.