Attenuation Relationship For Acceleration Spectra In The Northeast Seismic Zone Of China

Along with the implementation of ‘the plan of promotion Northeast oldIndustrial base’, the amount and scale of construction projects in theNortheast seismic zone increases largely, and the quality has been upgradedcontinually. The reasonable fortification against earthquakes is an effectivemeasure to reduce or avoid earthquake damage and safeguard people’s lifeand property. The seismic zoning, the earthquake microzoning and seismicsafety evaluation of engineering sites are the methods to certain the level offortification against earthquakes, of which attenuation relationship forground motion is one of key points. The differences between differentattenuation relationships for ground motion make vast effects to the result ofparameters of ground motion. The feature of attenuation relationship forground motion is determined by Earthquake source mechanisms, propagationpaths and site conditions. Different regions usually have different attenuationrelationship for ground motion, because of the diversities of geologicalstructures. The directly use of the attenuation relationship of intensity andground motion of Eastern China may course discrepancy with the feature ofground motion of our zone. Therefore, creating the attenuation relationshipof ground motion in accordance with the practical situation is necessary.In this thesis, isochronal line data of the Northeast Seismic Zoneearthquakes and the NGA strong ground motion database have been usedfully. The intensity attenuation in the Northeast Seismic Zone and theattenuation relationship of acceleration spectra in the western American areestablished. And then, the existing intensity attenuation relationship isselected. Based on the conversion method, the attenuation relationship ofacceleration spectra in the Northeast Seismic Zone is given. The concretework includes:1. A brief review of the domestic and international research processes ofintensity and ground motion attenuation relationships has made, andsummarized the research status of domestic intensity and ground motionattenuation relationships. And then, the urgency and necessity of establishingintensity and ground motion attenuation relationship in the Northeast seismiczone was pointed out.2. A brief introduction has been made for the common least squaremethod, multiple random variable statistical regression method and themethod of the conversion of researching the attenuation relationship foracceleration spectra. And then, the principle of choosing methods ofregression and conversion was fixed.3. Isochronal line data of the Northeast seismic zone has been collectedand arranged, the database of intensity material of the Northeast seismic zone was established, and the magnitute and the epicentral distance have beenweighted separately. With the method of multiple random variable statistiacalregression, intensity attenuation relationship in the Northeast seismic zonewas given, and a contrastive analysis has been made with the intensityattenuation relationship of Eastern China.4. Based on the NGA database, the recordings of strong ground motionhave been selected, and an analysis has been made for the featuredistribution of the strong ground motion recordings. And then, a further filterof the rock strong ground motion recordings was made to build theregression dataset. With the method of multiple random variable statisticalregression, the coefficients of attenuation relationship for response spectra inthe western USA were solved, and made a contrastive analysis with theexisted attenuation relationship.5. Following the basic thinking of conversion, the Western USA wasmade as the reference area and the Northeast seismic zone as the researcharea. Basing on the intensity attenuation relationship in the western USAmade by Chandra, the intensity attenuation relationship in the Northeastseismic zone and the horizontal rock attenuation relationship of accelerationspectra in the Western USA which were created in this thesis, using the I-Rmethod, the horizontal rock attenuation relationship of acceleration spectrawith the5%ratio of damping in the Northeast seismic zone of China havebeen given.