The Optimization Of Shear Wall In Frame-Shear Wall Structure Under Horizontal Earthquake Function

High-rise buildings are characteristic of great investment and Jong period. How to optimize its design has been the concentration of many scholars and structure engineers both at home and abroad. A commonly used way at home is to design by experience before checking computation. This method requires repeating and excess work and its quality greatly depends on the skills of designers. Some scholars put forward the idea of determining the reasonable amount of shear walls in frame-shear wall structure, for example, optimum design based on the optimal fortification intensity and minimum seismic effects. However, the required amount of shear walls by this way is not always economical. Based on a general survey of the seismic hazard, Japanese proposed the length and area of the shear wall per square meter as the bottom limit of the required number of shear walls so as to avoid destruction. The inner relationship between the stiffness of shear walls and seismic effects is not taken into consideration. Thus, it cannot solve the problem completely.In earthquake zone, if too few shear walls are made, it cannot help much to resist the horizontal load and because of great lateral deformation, the structure cannot meet the demands of safety and usage. While, if too many are made, it increases the material amount and self weight, shortens the natural period of vibration and enhances the effects of the earthquake action. So what matters most is to determine the optimal quantity of shear walls since it is the most fundamental factors relating to the safety and rationality of the skills.The paper summarizes the experience and achievements available. Optimal research is made on the reasonable stiffness of the shear wall in frame-shear wall structure. The major work is as follows:1. To calculate the objective function and constraint condition in optimum method, it presents the team-work principle of frame-shear wall structure and its structural analysis. Work out the fundamental differential equation by making use of the boundary condition to achieve the formula for internal force displacement in hinged and rigid connection system of frame-shear wall structure. Also, it suggests the solution to shearing rigidity of frame and the way to change the flexural stiffness of shear walls.2. The optimal stiffness characteristic value interval is discussed on the basis of the existing practical experience. And the formula for basic natural period of vibration is deduced.3. Set up the optimization model when the seismic action is least, which is derived from continuous analysis principle of team work in frame-shear wall structure, observing the earthquake resistant design code and meeting the limitation of maximum drift angle between stories. Meanwhile, a set of optimal program is written in the computer language VC. Simple and practical, it is fit for the primary design of high-rise buildings in earthquake zone.4. Through calculation and analysis, it works out how the stiffness of shear wall is related to height of building(H), self weight of structure (G), total layers (n), characteristic site period (T_g), maximum value of horizontal earthquake effects coefficient (α_max), allowablevalue of elastic drift angle ([θ]_max ) and the periodic reduction factor of non-load-bearing walls (Ψ_T). Besides, it proves the rationality of the achieved amount of shear walls by basic natural period of vibration of structure.5. An analysis is made on the similarities and differences in the reasonable number of shear walls of rigid connection and hinged connection system in frame-shear wall structure. Then, it discusses the various factors affecting the equivalent restraint rigidity and work out the amount of shear walls that can be reduced by changing the constraining moment of coupling wall-beam.