Abstract：To study the difference of site dynamic parameters and seismic response between unfrozen and frozen seasons，the characteristics of microtremors in frozen and unfrozen seasons were analyzed by 3-component observation in Harbin sites. The effect of frozen soil on site predominant frequency，site amplification factor，equivalent shear wave velocity and site classification were studied by microtremors H/V method. A method for estimating the thickness of the frozen soil was proposed. The results show that the frequency of the horizontal component of microtremors increases because of the frozen soil but the increase of the vertical component is not obvious，and that the increases of the predominant frequency are different among sites even if in the same area. The increase of the site predominant frequency is correlated with both the thickness of the frozen soil and the stiffness of site surface soil. The amplification factor of the site decreases due to the frozen soil，and the decease of the amplification factor is correlated to the stiffness of site surface soil rather than the thickness of the frozen soil. The thickness of the frozen soil can be estimated according to the shear wave velocity of the site and the predominant frequency of the H/V spectra ratio. Due to the frozen soil，the equivalent shear wave velocities，vs20 and vs30，increase by 13% and 11% on average in six sites respectively. The increase of vs20 does not affect the site classification of class II，but can change the site of class III into class II with vs20 of nearly 250 m/s. The increase of vs30 during the frozen season does not affect the site classification of class D.
师黎静1，陈盛扬1，黎 明2. 哈尔滨季节性冻土场地特征参数研究[J]. 岩石力学与工程学报, 2019, 38(5): 1053-1063.
SHI Lijing1，CHEN Shengyang1，LI Ming2. Research on the characteristic parameters of Harbin seasonal frozen soils. , 2019, 38(5): 1053-1063.
陈卓识，孟上九，袁晓铭. 中等强度地震下季冻区场地响应影响研究[J]. 土木工程学报，2013，46(增1)：166–171.(CHEN Zhuoshi，MENG Shangjiu，YUAN Xiaoming. The impact of parameters inseasonal frozen area response under moderate intensity earthquake[J]. China Civil Engineering Journal，2013，46(Supp.1)：166–171.(in Chinese))
[11]
中华人民共和国国家标准编写组. GB50011—2010建筑抗震设计规范[S]. 北京：中国建筑工业出版社，2010.(The National Standards Compilation Group of the People?s Republic of China. GB50011—2010 Code for seismic design of building[S]. Beijing：China Architecture and Building Press，2010.(in Chinese))
[9]
刘宇实，师黎静. 基于地脉动谱比法的场地特征参数快速测定[J]. 振动与冲击，2018，37(13)：235–242.(LIU Yushi，SHI Lijing. Site characteristic parameters quick measurement based on micro-tremor?s H/V spectra[J]. Journal of Vibration and shock，2018，37(13)：235–242.(in Chinese))
[5]
高 峰，陈兴冲，严松宏. 季节性冻土和多年冻土对场地地震反应的影响[J]. 岩石力学与工程学报，2006，25(8)：1 639–1 644.(GAO Feng，CHEN Xingchong，YAN Songhong. Influence of permafrost and seasonally frozen soil in seismic responses of sites[J]. Chinese Journal of Rock Mechanics and Engineering，2006，25(8)：1 639–1 644.(in Chinese))
[8]
JUNG H O，KIM H J，JO B G，et al. The microtremor HVSRs in the SW Korean Peninsula I：characteristics of the HVSR peak frequency and amplification[J]. Science，2010，327(327)：94–97.
[12]
Building Seismic Safety Council(BSSC). NEHRP recommended provisions for seismic regulations for new buildings and other structures[S]. Washington，D C：Federal Emergency Management Agency，2003.
[3]
LEBLANC A M，FORTIER R，ALLARD M，et al. Seismic cone penetration test and seismic tomography in permafrost[J]. Revue Canadienne De Géotechnique，2004，41(5)：796–813.
[2]
王大雁，朱元林，马 巍，等. 冻土超声波波速与冻土物理力学性质试验研究[J]. 岩石力学与工程学报，2003，22(11)：1 837–1 840. (WANG Dayan，ZHU Yuanlin，MA Wei，et al. Testing study on relationship between ultrasonic wave velocities and physico- mechanical property of frozen soils[J]. Chinese Journal of Rock Mechanics and Engineering，2003，22(11)：1 837–1 840.(in Chinese))
[4]
QI J，MA W，SUN C，et al. Ground motion analysis in seasonally frozen regions[J]. Cold Regions Science and Technology，2006，44(2)：111–120.
[6]
COX B R，WOOD C M，HAZIRBABA K. Frozen and unfrozen shear wave velocity seismic site classification of Fairbanks，Alaska[J]. Journal of Cold Regions Engineering，2015，26(3)：118–145.
[7]
齐吉琳，李海鹏，赖远明，等. 季节冻土场地上的地脉动特征[J]. 冰川冻土，2004，26(4)：449–453.(QI Jilin，LI Haipeng，LAI Yuanming，et al. Characteristics of microtremor in seasonally frozen ground[J]，Journal of Glaciology and Geocryology，2004，26(4)：449–453.(in Chinese))
[10]
NAKAMURA Y. A modified estimation method for amplification factor of ground and structures using the H/V spectral ratio[J/OL]. http：//www.sdr.co.jp，2012–03–01.
2019, Vol. 38 
