Analysis On Mechanical Property Of Integral Jacking-up Of Ancient Building

The integral jacking-up technology of building has already been adopted toprotect ancient buildings in several examples which achieved favorable effects due tothe development of the integral displacement technology. At present, there is nomature design method, design code and construction rule for integral jacking-up ofbuilding. The systematic theory research is far behind the engineering practice. Thedesign and construction of actual project mainly rely on previous engineeringexperience.The mechanical property of the underpinning plate is analyzed with ANSYS inthe integral jacking-up process of the east door of Yuzhen Palace. It is shown that themaximum deflection of the prestressed underpinning beam is1.47mm，whichsatisfies the requirement of the code for design of concrete structures in the integraljacking-up process of the east door of Yuzhen Palace. The maximum tensile stress ofthe concrete under the underpinning edge beam is1.328MPa in the loading stage. Theconcrete will not crack because1.328MPa is lower than the axial tensile strengthwhich is2.469MPa. The maximum tensile stress of the concrete under theunderpinning edge beam is5.2MPa after the unloading of the middle jack. Theconcrete will crack because5.2MPa is higher than the axial tensile strength which is2.469MPa. Temporary support should be set up to reduce the span in order to preventcracking of the concrete in actual construction.The mechanical property of the H section steel column is analyzed with ANSYSin this paper. The H section steel column is improved by changing the structure formaccording to the analysis results. It is shown that the maximum compressive stress ofthe H section steel column is234.6MPa，which is lower than the yeilding strength ofthe material. The structure of the improved supporting column is simple and transferload directly under the condition of invariable bearing capacity and material strength.The project cost is reduced effectively because the improved supporting column savematerial and be convenient for construction.