| Currently, DDBD method has become one of the focus and emphasis of the study.Itmainly has some advantages such as being able to meet the needs to differentperformance levels for owners better, directly using displacement of the framestructures as the control parameters, and being able to control the deformation of thestructure better, almost to achieve the seismic targets and so on, but there are manyimmature sides. So on the basis of existing theoretical and experimental study, throughusing the finite element software OpenSees to analysis the seismic performances of16PPC frame structures designed according to our current codes, this paper analyzes somePPC framework parameters of seismic performances which are related to the DDBDmethod. We mainly analyze the coefficient of variation of inter-story drift ratio whichcan be used to quantify performance levels of DDBD of PPC frameworks, and give theinter-story drift ratio with a certain reliability index as quantitative design referencevalues for part of the performance levels. In addition, the approximate range or the lawof the displacement ductility factor of PPC frame structures,stiffness coefficients, theratios of base shear,the ratio of top displacement, the equivalent damping ratio, theequivalent stiffness is given, and so are suggestions of the reference adjustment orshortcomings of the relevant parameters. So as to provide a reference when designingPPC frame structures with DDBD method or its simple way. The chief conclusions ofthe paper is as follows:①Coefficient of variation. Through collecting and analysising many examples wh-ich simulate experiments or actual earthquakes with the finite element softwareOpenSees, the coefficients of variation of inter-story drift ratio(including as a resistanceR and effects of S) are given with simulation of framework with the finite elementsoftware including the elastic and elastoplastic stages, using the performance functionZ=R-S, when quantifying the performance levels of the DDBD method with the reliableconceptual inter-story drift ratio. Considering the randomness of material strength andgravity loads, the coefficients of variation of inter-story drift ratio in the elastic andelastic-plastic stages as a resistance R are respectively:0.271,0.359,and the coefficientsof variation of inter-story drift ratio in the elastic and elastic-plastic stages as the effectof S are respectively:0.355,0.407.②Quantification of the level of basic integrity. When quantifying the level of basic integrity of DDBD method, the residual cracks width of frame stuctures after theearthquake are mainly considered when solving the maximum inter-story drift ratio ofthis level as the resistance R,0.2mm in this paper. The parameters of performance pointsat more severe earthquake obtained according to our codes at present are mainlyconsidered when solving the maximum inter-story drift ratio of this level as the effect ofS. After K-S test,statistical data and judgments, the reference values with a certainreliability quantifying performance levels are given:1/1142.2，whose reliability index is2.73, to ensure a probability of99.69%.And three proposals to quantify performances ofthe levels according to owners’ different requirements are given, including designreference values to ensure that the probability commonly, such as1/843.5(95%),1/937.5(97.5%).③Quantification the level of life safety. When quantifying the level of life safetyof DDBD method, the bearing capacity requirements in the definition of the level aremainly considered when solving the maximum inter-story drift ratio of this level as theresistance R, about the range of the period for bearing capacity of the frame structurebefore reaching the limit of bearing capacity, about85%~100%to percentage,90%ofthe limit of bearing capacity valued in accordance with the recommendations of thepaper.The parameters of performance points at rarely meet earthquake are mainlyconsidered when solving the maximum inter-story drift ratio of this level as the effect ofS. After K-S test,statistical data and judgments, the reference values with a certainreliability quantifying performance levels are given:1/152.0, whose reliability index is0.8066, to ensure a probability of79.01%. At the same time the reliability indexes andensuring the probability at85%and100%of the limit of bearing capacity are given asreference values for the adjustment. Finally, three reference proposals to quantify thelevel are given when the owners have different requirements.④Quantification the level of collapse prevention. When quantifying the level ofcollapse prevention of DDBD method, because this level is mainly relatively to collapsestate, the parameters of the performance points with bearing capacity dropped to85%ofthe limit and destroy not occurred are mainly considered when solving the maximuminter-story drift ratio of this level as the resistance R.The parameters of performancepoints at rarely meet earthquake are mainly considered when solving the maximuminter-story drift ratio of this level as the effect of S. After K-S test,statistical data andjudgments, the reference values with a certain reliability quantifying performance levelsare given:1/152.0, whose reliability index is3.13, to ensure a probability of99.91%. Finally, three reference proposals to quantify the level are given when the owners havedifferent requirements.⑤Study on other parameters of seismic performance. Through analysising theseismic performance of the PPC framework designed according to our current codes,therange of their coefficients of displacement ductility is3.2~5.5, Stiffness coefficients:0.00~0.100. Generally base shear ratio under more severe earthquake, resistanceearthquake, rarely met earthquake is1:2.43:4.22, vertex displacement ratio:1:2.76:6.86.Meanwhile, value ranges of equivalent damping ratio, laws of equivalent stiffness ratio,reference suggestions to design are given. |
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