Report - PEER - University of California, Berkeley

thickness of the inner wall is usually 24cm. The grade of mortar is usually M2.5, butcan be increased to M5.0 and M10.0 according to the requirement of seismic design.The transversal wall is taken as the load-bearing wall in the four buildings.Combining the four representative brick buildings with design intensities VI, VII,VIII and IX, and considering that the code requirement for intensity IX is a maximumof four-stories, a total of 14 samples of multistory dwelling brick buildings areobtained. The seismic design of these multistory dwelling brick buildings isconducted according to the Chinese “Code for seismic design of buildings” (GBJ11-89).Table 1. Representative multistory dwelling brick buildingsDesign parametersBuildings1 2 3 4Story 3 4 5 6Story height (m) 2.8 2.7 2.8 2.7Top story height (m) 2.9 2.8 2.8 2.7Bay (m) 3.3, 3.6 3.3 3.6 3.9Building width (m) 10.0 10.3 10.3 11.2Building length (m) 37.2 32.2 34.6 34.6Outer wall thickness (cm) 37 37 37 37Roof load (N/m 2 ) 3310 3310 3310 3310Floor load (N/m 2 ) 3790 3790 3790 37903. STRUCTURAL MODEL AND UNCERTAINTIES OF ITS PARAMETERSThe brick structure model is a shear stick model. The hysteretic model of a brick wallwith and without constructional columns used here is a trilinear model, which is givenby referring to a large number of references (Zhang 1998), as shown in Fig.1. Thedetails of the formulas of stiffness and strength in this model are given in Zhang(1998).The parameters of the structural model include the lumped mass, the viscousdamping ratio and the hysteretic model parameters. The lumped mass is usuallyassumed as deterministic. The viscous damping ratio of brick structures can beexpressed as in Zhang (2002):ξ = 0.008 + 0.55 A/F(1)410