Ground Motion Standard Cumulative Absolute Velocity And Its Application

In the field of earthquake engineering, researchers always want to find out aparameter that can reflect the damage ability of earthquake ground motions well, andtheir study on the ground motion parameters has never stopped. In1988, the electricpower research institute(EPRI) proposed that the cumulative absolute velocity (CAV)could be used in nuclear power plant earthquake alarm. The proposers think that CAVcan take both peak value and duration of the earthquake record into account and judgewhether the earthquake ground motion has damage ability well. In order to eliminate thetail effect of non destructive earthquake records, the electric power research instituteproposed standard cumulative absolute velocity (CAVSTD) in1991. From then on,researchers around the world have been studying the application of this parameter in allaspects. Based on these studies, the main work of this paper are as follows:1. Summarize the research of CAV-related parameters at home and abroad, whichmainly include the following six aspects: the research and application in earthquakeground motion damage ability assessment, the research and application in seismichazard analysis, the research and application in ground liquefaction, the research inCAV’s relevance to other damage parameters and its attenuation relationship, theresearch and application in earthquake early warning, the research and application innuclear power plant earthquake alarm.2. Referring to the electric power research institute’s research method to determinethe reasonable CAVSTDthreshold value, this paper studies the reasonable alarmthreshold value. We collect typical ground motion parameters, make some comparativeanalysis between all parameters, and find that CAVSTDis the best parameter todistinguish whether the earthquake ground motion has damage ability or not. Twomethods to identify CAVSTDreasonable threshold value are put forward. Consideringthe safety of nuclear power plant, the recommended threshold value is0.17g-s. Makinguse of the WenChuan earthquake data, we study the effect of frequency components onCAVSTD.The results show that the effect of low frequency components (mainly below10Hz) on CAVSTDis significant.3. By data fitting, we get the statistical relationship between ground motionparameters and intensity. The results show that the fitting result of CAVSTDis one of thebest. CAVSTDcan measure the damage ability of earthquake ground motions well.Through the statistical relationship, the intensity can be estimated. At the same time,CAVSTDcan be used as a new parameter for earthquake disaster assessment.4. A large number of ground motion records are input to the structure model weestablished and the structure damage performance levels are obtained, then we can getthe relationships between different ground motion parameters and structure damageperformance level. The results show that CAVSTDhas the best relationship with structuredamage performance level. In this paper, we get CAVSTD’s possible values rangecorresponding to different performance levels.