Research On Seismic Behavior And Design Method Of RC Shaft Tower With Column-supported Conversion In The First Floor

Shaft tower is one of the most important buildings in mining special structure. In general it is also the tallest building in the industrial square, and is the symbol of the mine. It has the characteristic, such as the bigger load, the taller story height, the bigger floor open hole, irregular vertical height, and so on. At present, due to the hysteresis of the design code, large diameter(>4.0 m) elevator lobby floor live load value is lack; the high(about 20.0 m) shear wall stability calculation method in Chinese code is also relatively vague. At the same time, in order to accelerate the construction of vertical shaft and reduce occupying time of the mouth of the well, the traditional layout of shaft tower structure will not be able to meet the actual needs, so this paper puts forward the design of extraction column using column-supported conversion. The shaft tower belongs to unable interrupting building in and after earthquake, so the seismic performance is studied and analyzed. Based on the characteristics of shaft tower all in above, main research contents and achievements of the project list as follows:(1) Based on the lack of the bigger diameter(4.5m, 5.0m) elevator lobby floor live load in “Code for design of colliery building and structure of coal mine(GB50592-2010)”, it was received through analysis and calculation after survey of construction in process and constructed shaft tower and manufacturer factory.(2) Based on the needs of the shaft tower construction technology at present, the design scheme of "extraction column" as column-supported conversion in the first floor was proposed. In order to reduce the weight of transfer beam, this paper puts forward that shell element can be used instead of beam element after analysis and calculating of elastic shaft tower structure. Through detailed hollowed out optimized design scheme, it is concluded that the truss design scheme meets the needs of practical, at the same time corresponding suggestions about the design method of conversion components are listed.(3) Based on characteristics of special function, complex structure, higher seismic performance requirements, shaft tower’s structural PERFORM-3D FEA elastic-plastic model was established before and after the extraction column, then the seismic performance of whole and key components are analyzed. After comparing analysis of dynamic characteristics, story drift, base shear, energy dissipation, vertex displacement, the whole yield mechanism and so on, seismic performance of the column-supported conversion shaft tower was analyzed and evaluated using of bending, shearing and other performance index, and the results showed that shaft tower structure has good seismic performance after extraction column.(4) Based on the shear wall in the out-of-plane bending instability and floor under vertical board face load have the same deformation characteristics, think of elastic theory and the thin plate theory, the beam plate relative bending stiffness and tensional stiffness is introduced into the shear wall and buttress column relative stiffness calculation, using the finite element simulation method to define constraint boundary conditions. On the theory of small deflection bending deformation of shear walls, calculation equation considering elastic support beam was established, and the program of equilibrium method is compiled to calculate the shear wall stability bearing capacity. On this basis, combining with the calculation method in “Technical specification for concrete structures of tall building(JGJ3-2010)”, two suitable calculation methods for big tall shear wall stability which is the analytical method and ANSYS FEA calculation method are proposed.(5) Based on the effects of buttress column or wing wall to big high shear wall, in order to make full use of bending and shear performance of the shear wall, shear wall thickness was designed again using theory and method offered in this paper. Contrastive analysis was completed between the thinner shear wall shaft tower and the primary structure in a whole and some key components. Conclusion showed that the thinner shear wall can meet the stability and reduce the weight. At the same time, bending and shear performance of the shear wall can be made more full use, and the whole structure still have good seismic performance.