摘要
针对中国现行双参数场地分类法不能反映土层结构的问题,提出了利用可反映土层结构的场地基本周期估算公式进行改进的方案。通过改写现行土层等效剪切波速计算公式的形式,指出利用子层周期求和法计算场地基本周期是造成现行场地分类法存在问题的症结所在,提出了利用可反映土层结构的场地基本周期公式对其进行替换,形成新的土层等效剪切波速计算公式。结果表明,新公式计算的土层等效剪切波速变化规律和反应谱特征周期变化规律相一致,而从规范公式所得的结果却无变化。因此,新公式比规范公式更能灵敏反映场地特征的变化。
The current site classification in China could not reflect the soil layer structure,in order to solve this problem,a site fundamental period estimation formula which could reflect soil layer structure was introduced to modify the current site classification scheme. By rewriting the calculation formula of the current soil layer equivalent shear wave velocity,the crux of the problem was pointed out that the site fundament period was calculated by sub- layer periods summation method. The method was replaced by a site fundamental period formula which could reflect soil layer structure,and then a new calculation formula of soil layer equivalent shear wave velocity was put forward naturally. The results show that the change rule of soil layer equivalent shear wave velocity calculated from the new formula is consistant with that of response spectrum characteristic period,but the results form current formula kept constant. A conclusion could be drawn that the new formula could more sensitively reflect the variation of site properties.
引文
[1]GB17741-2005工程场地地震安全性评价[S].北京:中国标准出版社,2005.GB17741-2005 Seismic safety evaluation of engineering sites[S].Beijing:China standardization Press,2005.(in Chinese)
[2]CEN.Eurocode8:Design of structures for earthquake resistance-Part1:General rules,seismic actions and rules for building[S].Bruxelles:European Committee for Standardization,2004.
[3]Building Seismic Safety Council(BSSC),[1997,2000].1997 Edition NEHRP recommended provisions for the development of seismic regulations for new buildings and other structures,FEMA 302/303[R].Washington,DC.
[4]BCJ.Structural provisions for building structures[S].Building Center of Japan,1997(in Chinese)
[5]GB50011-2010建筑抗震设计规范[S].北京:中国建筑工业出版社,2010.GB50011-2010 Code for Seismic Design of Buildings[S].Beijing:Building Industry Press of China,2010.(in Chinese)
[6]李秀领.土层结构对地表地震动参数影响的研究[D].哈尔滨:中国地震局工程力学研究所,2003.LI Xiuling.Study on the Effect of Soil Layer Construction on Ground Motion Parameters[D].Harbin:Institute of Engineering Mechanics,CEA.(in Chinese)
[7]GB50011-2001建筑抗震设计规范[S].北京:中国建筑工业出版社,2010.GB50011-2001 Code for Seismic Design of Buildings[S].Beijing:Building Industry Press of China,2001.(in Chinese)
[8]薄景山,翟庆生,吴兆营,等.基于土层结构的场地分类方法[J].地震工程与工程振动,2004,24(4):46-49.BO Jingshan,ZHAI Qingsheng,WU Zhaoying,et al.Site classification method based on soil layer construction[J].Chinese Journal of Earthquake Engineering and Engineering Vibration,2004,24(4):46-49.(in Chinese)
[9]《工程地质手册》编委会.工程地质手册[M].第四版.北京:中国建筑工业出版社,2006:591.Editorial board of Engineering geology manual.Engineering geology manual[M].4th edition Fourth edition.Beijing:China Building Industry Press,2006:591.(in Chinese)
[10]周锡元,王广军,苏经宇.场地分类和平均反应谱[J].岩土工程学报,1984,6(5):59-68.ZHOU Xiyuan,WANG Guangjun,SU Jingyu.Site classification and average response spectra[J].Chinese Journal of Geotechnical Engineering,1984,6(5):59-68.(in Chinese)
[11]齐文浩,薄景山,刘红帅.水平成层场地基本周期的估算公式[J].岩土工程学报,2013,35(4):779-784.QI Wenhao,BO Jingshan,LIU Hongshuai.Fundamental period formula for horizontal layered soil profiles[J].Chinese Journal of Geotechnical Engineering,2013,35(4):779-784.(in Chinese)