Study On Layout Of Shear Walls In Frame-shear Wall Structures With L-shaped Plane

In the current urban construction, more and more building structures with asymmetric plane have sprung up, of which the ones with L-shaped plane are typical representative. As the center of mass does not coincide with the center of stiffness, together with the influence of torsional component in the earthquake action, these structures are more prone to suffer torsional damage. This has attracted much attention in the engineering, and some important research results have been obtained to play important part in instructing engineering practice.However, with ever-changing structure forms, various factors and influence degrees, many design problems still need to be solved urgently in the practical projects. In the structural design for a horizontally L-shape building in the seismic zone with precautionary intensity 8, two difficulties are encountered: (1) torsional response of the structure under horizontal earthquake action is significant; (2) internal force of shear walls under horizontal earthquake action is out of limit. Therefore, the paper takes the frame-shear wall structure located in high seismic intensity region as research object, emphatically discussing the comprehensive impact of layout of shear walls on horizontal earthquake effects of both overall structure and shear walls. Frame-shear wall structures with symmetric and asymmetric planes are modeled in structural analysis software PKPM and ETABS, in which horizontal earthquake effects are calculated by modal response spectrum method. By analyzing and comparing various layouts of shear walls, effective methods are summarized to solve practical engineering problems.The present paper firstly introduces the general situation and design problems of the practical project, primarily exploring the reasons for such problems. Secondly, frame-shear wall structures with symmetric plane are set up to acquire some common laws for controlling entire structural torsion and adjusting internal force of shear walls, while the location, number and section length of shear walls are transformed. Afterwards, frame-shear wall structures with asymmetric plane are modeled to study following topics: the influence of eccentric direction on torsional effect, the reasonable location of stiffness center, the concept of general symmetry and equivalent layout, as well as the impact of different directions and combinations of horizontal earthquake action on torsional response and shear walls'performance in the horizontally L-shaped structure. Finally, the suitable scheme of torsion control and internal force conditioning is designed for the project case, in which the floor stress and stiffness of coupling beams are focused on or adjusted. The layout ideas of shear walls in structures with L-shaped plane are summarized, providing references for the design of similar projects.