Stability Analysis And Application Research Of Temporary Support For Extra-thick Foundation Slab

In the construction of the super-thick floor of the super-tall buildings,as an important measure to ensure safety,temporary support of reinforcement for the foundation,due to the lack of corresponding design and verification criteria,meanwhile,it is difficult to guarantee the construction quality of the site,this kind of safety accident happens frequently in recent years.This article uses ANSYS software for finite element analysis,the temporary support structure of the reinforcement of the ultra-thick floor was studied,the main tasks are as follows:The temporary support structure with super thick floor has many initial defects,this article uses the finite element software combined with the investigation results of the initial bending of the channel steel,the influence of initial bending waveform,direction and amplitude on the mechanical properties of channel steel rods is analyzed.Combined with the research results of joint structure and joint welding quality,for the 4 different connection forms in the actual project,the influence of joint form and underweld on joint stiffness is studied,the stiffness distribution of the joint under the continuous weld with different lengths and positions is obtained,the research method of node quality based on joint stiffness is given,the model of beam element is improved by using spring element.The refined modeling method of temporary support structure is given,and the feasibility of the finite element modeling method is verified by field loading test.To optimize the layout plan of temporary support structure,a standard finite element analysis model of temporary support was established,the nonlinear bending analysis of the model was carried out by introducing the initial bending of the members and joint defects,and the failure modes and corresponding critical loads of the hinged and rigidly connected temporary support structures under different joint defect forms were obtained.By adding joints with different welding qualities at random positions in the model,a semi-rigid model considering the forms of joints and welding quality was established,and then the adverse influence coefficient of the temporary support structure considering the forms of joints and welding quality was obtained.Combined with the related research results,structural optimization and innovation were carried out,and the parameters of the cross bracing layout angle were optimized.The structural measures of the layout of the bracing were proposed according to the damage characteristics,and the original model was effectively improved.The layout scheme of the temporary support structure of the ultra-thick floor with different heights is designed,and the suggestions for the selection of the corresponding members are given.The technological process and relevant design and construction suggestions of the temporary support structure of the ultra-thick floor are given,and implemented the application of demonstration projects.