Study On Supporting Design Optimization Of Supporting System In Block A7 Of Tongde Square In Kunming

The foundation pit engineering in the city not only needs to meet the safety of the supporting structure,but also strictly controls the influence of its supporting form on the surrounding environment.Never use the red line too much.In this context,combined with numerical analysis method,the variation of foundation pits during the construction of open excavation method is analyzed,and the deformation and bending moment of undergr ound continuous wall during excavation are studied.The influence of the subsoil and the retaining structure,the deformation trend of the retaining structure,etc.,after the monito ring report and the analysis and screening of the finite element simulation result data,the bending moment,axial force,shearing force and torque under the most unfavorable str ess conditions are obtained.Substitute the structure software to calculate the cross-section reinforcement of the rod and compare it with the original design,The influence of the change of the depth of diaphragm wall on the deformation of supporting structure is also analyzed by simulating the change of the depth of diaphragm wall.The main conclusions are as follows:(1)The vertical vertical displacement of the grounding wall is caused by the large vertical and wall pressure on both sides of the grounding wall and the upper and lower parts of the wall.When the wall surface is deformed,the stress on both sides is biased upward.The resultant force F1,at this time,when the bottom of the wall is subjected to the vertical deformation of the bottom of the wall due to the unloading of the bottom of the pit,the vertical thrust F2 of the bottom of the wall is easily generated when the combined force of F1 and F2 is greater than the weight of the wall.The displacement.(2)The underground continuous wall excavates with the soil,resulting in uneven force on both sides of the ground wall,the downward movement of the active earth pressure and the lateral stiffness provided by the inner support on the wall,so that the force of the ground wall The type is from the beginning of the cantilever member to the rear wall joint,and the bottom is similar to the fixed bearing and the one-way restraint.(3)Surface load can effectively reduce the heave of pit bottom,reduce the vertical displacement of columns and internal supports,and provide effective help to resist the vertical enclosure structure with insufficient overturning.But for diaphragm walls with larger stiffness,it will cause the wall to rotate around the position of the maximum principal stress(Side and middle of wall),resulting in one pile position failure,and the effect of the whole enclosure structure will be great.Sell at a discount.(4)From the point of view of mechanics,with the decrease of diaphragm wall depth by 1 m,the minimum vertical displacement of enclosure structure increases by 0.17 mm,with an average growth rate of 12.4%.and the final(working condition 4)average growth rate is 4.66 mm;the top displacement of the wall increases by 0.27 mm,the bottom displacement of the wall increases by 4.04 mm,the maximum deformation increases by 5.79 mm,and the maximum deformation speed increases rapidly.(5)In the internal bracing system,local members have optimization space.For example,the weight of reinforcement in the middle of the third internal bracing section is optimized by9.67%,and the area of reinforcement is reduced by 9.67%.