Analysis On Technologies And Mechanical Properties In Jacking-up Of An Ancient Building

In recent years, with the rapid economic development and urban construction inour country, some existed buildings have to be removed or relocated because there arecontradictions between the proposed projects and the original ones in location,planning, impacts, and etc. However, if some buildings with important history valuesor use values are removed, they will lead to incalculable losses. Integrally jacking-uptechnology of architecture can resolve the contradiction reasonably. And thetechnology can remain some ancient buildings which may be removed on theiroriginal sites. It has a broad application prospect and practical value, and has beenused widely.The construction scheme of the integrally jacking-up project of the mountain gatein Hubei province Wudang mountain Yuzhen palace is introduced in this paper. Thescheme includes pre-reinforcement, precipitation, building reaction basis, constructingunderpinning structure, integrally jacking-up and setting isolation bearing. In addition,the emphases and difficulties of the project are introduced in this paper, including theincremental launching of the steel box girders, the construction of the underpinningstructure, and the integrally jacking-up of the ancient architecture.The ABAQUS finite element software is used to analyze the mechanicalbehaviours of steel box birders in the incremental launching process and themechanical properties of the underpinning structure in the jacking-up process.The research shows that in the incremental launching process, the thrust forces ofjacks of finite element model and the measured data are consistent. The maximumthrust force of jack increases with jacking depth increasing. The steel box girderswon’t failure during the jacking process. Setting steel backing plate or cushion blockcould be done to prevent excessive local stress. The deformations of the steel boxgirders are small after soil excavation.In the integrally jacking-up process, the maximum deflection of the prestressedunderpinning beam is3.77mm, which is1/3200of the calculation span. The projectmeets the regulation on limited value of deflection. It is shown that setting steel plateand prestressed rebar in the underpinning beam can reduce its deformation effectivelyand make the structure more safety. Moreover, the maximum tension stresses inconcrete of two underpinning edge beams are2.2MPa and0.7MPa. While the values are lower than the axial tensile strength of concrete which is2.5MPa, the former is88%of the axial tensile strength of concrete. Considered that the concrete maybeuneven and not dense during the pouring process, the underpinning edge beam maybecrack in the engineering.