四川盆地场地土动力学参数统计研究  

Research on dynamic parameters of site soil in Sichuan basin

作　　者：史丙新[1] 周荣军[1] 

机构地区：[1]四川省地震局,四川成都610041

出　　处：《四川地震》2014年第3期1-5,共5页Earthquake Research in Sichuan

摘　　要：四川盆地地震构造环境相对稳定,主要遭受近场中强地震和外围大地震的影响。盆地内第四系主要为河流相的砂卵石层夹粘土、粉土层,分布于成都平原及盆地内外河流两岸。这种地层在土层地震反应计算时往往产生一个峰值,具有显著的放大作用。本文收集共计123组土动力学参数的实验资料,统计分析了淤泥质土、粉质粘土、粘土、粉土、细砂和全风化泥岩等6种土类实测土动力学参数,给出了它们在不同深度下的动剪切模量比和阻尼比的统计值。并且将统计值和"94"规范值与袁晓铭推荐值[9]进行了对比分析,结果表明在盆地内使用规范值和推荐值会对工程的抗震设防产生不利影响。该研究成果对盆地内各类工程建设的工程场地地震安全性评价工作具有一定的借鉴和参考价值。The earthquake tectonic environment in Sichuan basin is relatively stable, mainly suffering from strong earthquakes in the near field and the peripheral impact of the earthquake. The Quaternary strata within the basin is mainly fluvial sand and gravel layer which is sandwiched clay, silt, located in the Chengdu Plain and external sides of the river basin. Such stratum in the soil seismic response calculations tends to produce a peak, with significant amplification. The soil dynamic parameters of experimental data amount to 123 in seismic safety evaluation reports are collected. The data are divided into 6 types based on lithology, such as mucky soil, silty clay, clay, silt, silty fine sand and completely weathered mudstone. Statistics of the dynamic parameters of soil analysis are carried out to obtain the mean values of dynamic shear modulus ratio and damping ratio at different depths. These statistical val- Ues of dynamic parameters are compared with the recommended values in 94 Code and YUAN Xiao - ming respec- tively. Our results show that in the basin using specifications and recommended values can result in adverse effects on the earthquake fortification works and illustrates that the use of statistics is more reasonable. The results can be taken as a reference of the soil dynamic value in this area and can be used in the seismic risk assessment of engineering projects.

关 键 词：场地土 土动力学参数 四川盆地 动剪切模量比 阻尼比 

分 类 号：TU411.8[建筑科学—岩土工程]