Study On Seismic Capacity Demands Of RC Shear Walls In Chinese Intensity Region 8(0.30g)

For the past few years,strong earthquake occurs frequently. The capacity of urban high-rise building in earthquake disaster mitigation is very important. Shear wall is the key component of high-rise building structure. Achieving the expected failure mode under strong earthquake is an effective guarantee to improve the seismic performance of high-rise structure effectively, especially to improve the ability of anti-collapse. T. Paulay,a famous scholar of New Zealand,putted forward capacity design method to realize expected failure modes. Cantilever shear wall components designed for " strong shear weak bending " and " the plastic hinge appeared at the bottom of wall ",capacity design methods were putted forward in many country codes to corresponding that. Foreign scholars studied the regular of bending moment and shear force amplification for RC shear wall under strong earthquake,they putted forward formulas to calculate amplification coefficient. while,internal study is less,there were a lack of targeted study on specifications in Chinese code. A plenty of work needed to carry out urgently.The study focuses on the seismic capacity demands on RC shear walls in Chinese intensity region 8(0.30g). Structure height,stiffness ratio of frame-shear wall structure and integrity coefficient of shear wall structure are considered. This paper wants to discover the distribution regularities about seismic force demand and seismic flexural demand along the height. This paper reviews the national codes and study on the capacity design method on RC cantilever walls. This paper verified capacity design methods of 2010 Chinese Code by two frame- shear wall structures and one shear wall structure. Twelve frame- shear wall structures and seven shear wall structures are designed according to expected failure mode,then elastic-plastic time history analysis were applied to these study models. Distribution regularities about seismic force demand and seismic flexural demand along the height are summarized. Also,the amplification coefficients that taked into account the effect about axial force under strong earthquake and their distribution regularities along the height are summarized.There are the main conclusions about this paper:①The capacity design coefficients of RC shear wall in each country code are obviously different,the Chinese code coefficients are smaller than abroad.②The structure designed by 2010 Chinese Code flexural yield above strengthen area and shear yield in strengthen area,it’s an unexpected failure mode.③With the increase of stiffness ratio or integrity coefficient and structure height,the flexural amplification coefficient become larger. Generally,it’s larger than 2010 Chinese Code,some floor’s flexural demand under strong earthquake are larger than constructional flexural capacity.④ With the increase of stiffness ratio or integrity coefficient, the shear amplification coefficient become larger in strengthen area and larger decrease after first above strengthen area. with the increase of structure height the shear amplification coefficient become larger. Generally,it’s larger than 2010 Chinese Code. Some shear wall structure models’ shear force demand under strong earthquake at the bottom are larger than constructional shear capacity.⑤Because of the internal force redistribution,frame- shear wall structure’s amplification coefficient is smaller than shear wall structure’s amplification coefficient.⑥The flexural demand along the height under strong earthquake are different,maybe we can take Trilinear envelope design method. The structural reinforcement ratio at the bottom cross section of shear wall structure should be enhance,the larger the integrity coefficient,the greater the enhance.