Study On Stability Analysis And Support Technology Of Deep Foundation Pit Support

Take the example of a company!s 500,000 tons/year ethylene glycol project accident pool and production wastewater pool foundation pit.Through the theoretical design c-alculation of the foun-dation pit,the MIDAS/GTS finite element software constructi-on simulation and the feedback data of the construction site.Combined with the supp-orting structure form selected by the foundation pit project and the site's various test data during the excavation construction process,the construction feasibili-ty verificati-on and the prevention and treatment of important problems in the constru-ction are carried out The main research work and achievements are as follows:1.The detailed engineering geological geotechnical investigation report can pr-ovide accurate engineering geological conditions and geotechnical engineering para-meters.It is of guiding signi-ficance in the preliminary work of the foundation pit,especially the selection of the foundation pit support structure.2.Through the rational deep foundation pit software,the earth pressure,displac-ement,bendi-ng bending moment and shear force of the foundation pit in seven work-ing conditions are analy-zed and calculated,and the overall stability and antilifting s-tability of the foundation pit are verified.The correct calculation results meet the req-uirements indicating the correctness of the calculation structure.In addition,this paper also uses the design software of Lizheng deep founda-tion pit to design and calculate steel support,steel cofferdam and column and column pile.3.Using the MIDAS/GTS software,the Mohr-Coulomb model is selected as the constitutive model of the soil.The three-dimensional model of the foundation pit is established on the assump-tion that the soil is isotropic and uniform elastoplastic and does not consider the seepage effect of groundwater.During the simulation of founda-tion pit excavation,the maximum horizontal displa-cement of the pile top of the retai-ning pile appears at the corner and middle of the supporting structure.The maximum values in the X and Y directions are 5.7 mm and 6 mm.The lateral displacement of the retaining pile has a great influence.The increase of the excavation depth leads to the gradual imbalance of the earth pressure on both sides of the retaining structure,which leads to the horizontal displacement.The foundation pit should consider the time effect during the constru-ction process.According to the influence of space eff-ect.the stratification number,excavation position and size of each excavation of the f-oundation pit shall be designed according to the corresponding specifications.The cor-responding bracket shall be erected at the same time when the foundation pit is excav-ated.4.The results obtained by numerical simulation analysis are basicallyconsistent with the on-site monitoring data.As long as the rock mass data of the project site is correct and the model is simplified and reasonable,the numerical simulation is appli-ed to the deformation prediction of large deep foundation pits,which can bring good practical value to guide the construction.Figure[69]table[24]reference[59]...