Report - PEER - University of California, Berkeley

compressive stress of concrete is two-thirds of the nominal compressive strength,allowable shear stress of concrete is one-twentieth of the nominal compressivestrength, and allowable tensile stress of reinforcing bars is the nominal yield stress.The design snow depth is specified by MOLIT Notification 1455. The method toevaluate design wind forces is specified, and the parameters to define the windpressure are specified by MOLIT Notification 1454. The method to evaluate designearthquake forces is specified, and seismic zone factor is specified by MOLITNotification 1918. The amplitude of snow loads, wind forces and earthquake forcesused here may be expected once in fifty years. The safety of roofing materials underdesign wind pressure shall be examined by the calculation method set forth byMOLIT Notification 1458. The story drift under design earthquake forces shall beless than 1/200 of the story height, but the value may be relaxed to 1/120 if theperformance of the building is shown to be acceptable. For buildings less than 31 m inheight, the eccentricity in plan and stiffness distribution along the building heightshall satisfy limiting values and the structural calculation, set forth by MOLIT shallbe carried out. For buildings taller than 31 m, the ultimate story resistance at theformation of collapse mechanism under lateral loading shall be larger than therequired value, which takes in account (a) eccentricity in plan and stiffnessdistribution along the building height, and (b) deformation capacity of yieldingmembers.3.6 Ultimate Strength CalculationThe allowable stress calculation for the combination of dead and live loads using theallowable stress of materials for long term loading and the allowable stress calculationfor the combination of (a) dead, live and snow loads, and (b) dead and live loads andwind forces using the allowable stress of materials for short term loading shall becarried out. The amplitude of snow loads and wind forces used here may correspondto the values expected once in 50 years.The forces in any structural members shall not exceed the ultimate strengthcalculated using the ultimate strength of materials under the combination of (a) deadand live loads and 1.4 times the snow load at the construction site, and (b) dead andlive loads and 1.6 times the wind force at the construction site. The amplitude of theamplified snow load and wind force used here may correspond to the values beexpected once in 500 years.The design earthquake motion is defined by the response spectrum of 0.05damping factor specified at engineering bed rock (soil layer whose shear wavevelocity is approximately 400 m/sec and above), and the response spectrum of groundmotion at the base of the structure shall be calculated taking into consideration theamplification by surface geology. The intensity of ground motion at the engineeringbedrocks is specified for two levels; one corresponding to a rare event of once in 50years, and the other corresponding to an extraordinary rare event of once in 500 years.The intensity level of the former earthquake motion is one-fifth of the latter525