Estimation Of Site Coefficient Based On KiK-net Strong-motion Seismograph Network

Previous earthquake damage investigations indicate that Site conditions have an important effect on earthquake damage.the reason why the abnormal earthquake events listed in literature[2] come out is that local site conditions play a significant role in these earthquake events.site conditions also affect the design response spectrum,the GB50011-2016 code for seismic design of buildings adjust both the period value and peak acceleration value.so it is need close attention of site conditions effects in earthquake engineering and structure engineering.There are large amounts of acceleration records both at ground surface and at the bottom of boreholes of KiK-net strong-motion seismograph network.In order to ensure the rationality of statistical results,these strong-motion records are selected considering magnitude,epicentral distance,focal depth and peak acceleration values.1609 pairs of strong-motion with horizontal component records during 170 earthquakes are selected,every pair of strong-motion records contains both seismic motions at ground surface and the corresponding ones at the bottom of borehole.The conclusions are as follows:First,The relationships between site amplification factor,site coefficient and site classifications,peak acceleration are investigated,and the influences of 3 different definitions of EPA on site amplification factor and site coefficient are compared using these strong-motion records.The results show that maximum value of amplification factor is that of type ?,next is that of type ?,that of type? is the minimum;Additionally,there is some difference of amplification factor and site coefficient when calculated from three different definitions of EPA.Finally the suggested site coefficient table of different types of sites is given.Second,for a reference of the attenuation relation model listed in GB18306-2015 seismic zonation map teaching material,the attenuation realtion model in this paper is simplified.by magnitude 6.5,the PGA and EPA are made a linear regression,the relationship between seimic attenuation relation and magnitude,site types,PGA,EPA are studied.the results show that 1)generally,the attenuation rate of site?and ?is bigger than type ?;2)for site type ?,the attenuation rate of EPA is bigger than that of PGA;for site type?,the attenuation rate of EPA is almost same as that of PGA;for site type ?,the attenuation rate of PGA is bigger than that of EPA when M?6.5.Finally,the suggestions of the future research work is prospected.