Seismic Performance Of High-rise Steel And Concrete Composite Structure Research

Earthquake is one of the most serious disasters harm in the nature, and also is one of the key control loads in most engineering structures. Our country is a frequent earthquake place, and about half of the city is located in the basic intensity of 7 and 7 degrees above areas. The building is the space of human daily life, during the earthquake, once the buildings collapsed, it will brings serious disaster to mankind. With the continuous increase of building height and the using function has become increasingly complex, the single structure form can not meet the requirements of architectural design. The composite structure whose main stressed components is steel-concrete composite beams or columns. Currently, it development rapidly and be widely used, and now as a structure form, is widely applied in the field of high-rise buildings. But the seismic performance research of this kind of structure is seriously lagging behind the engineering practice. Therefore, to study on the seismic behavior of the structures is an important subject.In the many factors that affect seismic, the paper selected the thickness of the core tube and connection stiffness of frame beams with shear wall as factors, and started from them, according to the practical engineering, established a 15-story steel-concrete combination structural model by using Sap2000 program software, by sequentially changing the thickness of the core tube and the connection stiffness of frame beams with shear wall to setting up comparison models. Accordance with the specifications, made linear and nonlinear seismic response analysis with 7-degree rare earthquake. By comparing vibration period, layer displacement, interlayer displacement angle, floor shear, base shear-vertex displacement, the performance point of the structure and the development of plastic hinges to get the earthquake response of the structural in a different core tube thickness and connection stiffness of frame beams with shear wall. So as to explore the core tube thickness and the connection stiffness of frame beams with shear wall changes on seismic performance of structures. And the basic results as follows:(1) Under the earthquake, different core tube thickness and connection stiffness of frame beams with shear wall influenced the deformation and shear of the structure. The distribution of the layer displacement, interlayer displacement angle and floor shear along the floor height is substantially the same.(2) The deformation curve is cut-shear. Because below the steel-concrete composite structures, mainly rely on concrete tube to resist loads, this will make the deformation curve of the structure is presented as curved. In the above of composite structure, it is largely dependent on the steel frame to resist loads, the interlayer deformation is relatively small to a certain degree, thus leading to the degree of concrete tube outwardly curved will also be less, so that the deformation curve of the structure is presented as shearing.(3) The greater the thickness of core tube and connection stiffness of frame beams with shear wall, the smaller the vibration period of the structure, and the greater the rigidity of the structure, so that the smaller the displacement response of the structure, and the greater the floor shear of the structure, and the better the seismic performance, and vice versa.The change of the tube thickness and connection stiffness of frame beams with shear wall mainly influenced the displacement response of the top and the floor shear of the bottom, and little effect on the displacement response of the bottom and the floor shear of the top.(4) Under the same vertex displacement, Shear wall thickness and frame beam and shear wall connection stiffness is in direct proportional to the structure of the base shear, The greater the thickness of core tube and connection stiffness of frame beams with shear wall, the bigger the base shear, and the greater the ultimate bearing capacity of structure.(5) In Pushover analysis, capacity spectrum curve and the demand curve intersect, and performance parameters are reasonable.Most of the definition of hinge in flexible working state, and in plastic state of the hinge is located in the state of CP, which did not reach the state of the collapsed show that deformation of structure has good performance. And most of plastic hinge appeared on the beam, conform to the structure of "strong column weak beam" design requirements.Through the seismic analysis in the paper, in order to provide a reference for practical engineering experience.