南京砂的结构特性与地铁地基液化判别  

Characters of schistose structure of Nanjing's sand and seismic liquefaction of subsoil of a metro section

作　　者：陈文化[1] 孙谋[2] 刘明丽[1] 胡新鹏[2] 曾根平[1] 

机构地区：[1]北方交通大学土建学院,北京100044 [2]中铁隧道集团一处有限公司,河南新乡453000

出　　处：《岩土力学》2003年第5期755-758,共4页Rock and Soil Mechanics

摘　　要：与圆颗粒的标准砂相比较,片状结构的砂的动力特性更为复杂,用规范法进行液化判别时会误判。为了将砂土片状结构特性考虑到判别过程中,建议了一个更为合理的Ncr 的经验公式,并利用该公式对南京地铁玄武门-南京站区间的砂土层进行液化判别,该区间会发生中等程度为主的液化,最后,将液化判别结果与规范法和室内动力实验结果相比较,分析发现,在南京地铁进行液化判别时,必须考虑片状结构特性对于液化影响;同时,给出了平均液化势随深度的变化情况,以及考虑砂土结构特性对判别结果的影响系数随土层深度的关系,提高了判别的精度。Some dynamical characters and seismic liquefaction of schistose grain sand are very complex and different to that of the round grain sand; We may reduce the degree of liquefaction if by using the method of code without considering the characters of schistose structure. A new empirical formula of Ncr is suggested to evaluate the seismic liquefaction of subsoil of a metro with considering the schistose structure of Nanjing's sand. According this new method the index of liquefaction of subsoil of a metro section from Xuanwumen station to Nanjing station is middle degree, The distribution of affect-coefficient and index of liquefaction are also described with depth. It is important to take care of the schistose structures to analyze the seismic liquefaction in Nanjing; this result is testified to be correct by dynamical test; the research can improve the accuracy of evaluation.

关 键 词：地铁地基 片状结构 液化判别 修正的经验公式 

分 类 号：TV223[水利工程—水工结构工程]