扬州地区粉土动力特性试验研究

发布时间：2018-06-21 01:07

本文选题：粉土 + 动力特性　；参考：《扬州大学》2015年硕士论文

【摘要】：地震是危机人民生命财产的突发式自然灾害,其对人类造成的经济损失、人员伤亡及人类心灵伤痛十分惨重,尤其在当今经济飞速发展的时代,城市化进程飞速发展,人口及物质财务高度集中,由此现代地震带来的损失也将会更加巨大。大量震害经验表明,地震造成地基破坏一个很重要的因素是粉土在动力荷载下发生液化失稳。粉土是一种过渡性土,介于砂土和粘土之间,含有砂粒、粉粒、粘粒三种颗粒成分,其中粘粒和粉粒统称为细粒。粉土的工程性质既不同于粘性土又有别于砂土,具有独特的性质。本文以扬州地区实际工程粉土地基为对象,进行动三轴试验、静三轴试验研究,并将室内试验结果与现场标准贯入试验结果进行对比分析,主要内容有：(1)通过DDS-70微机控制电磁式振动三轴仪进行粉土动三轴固结不排水试验,得到动剪切强度与破坏振次之间的关系及相关曲线,结果表明：同种土施加围压越大,其动剪应力值越大,即动剪应力值τd越大土样抗液化能力越强,由此可知增大围压能够提高饱和粉土的抗液化强度。(2)通过应变控制式静力三轴仪进行粉土静三轴固结排水试验,得到相关破坏曲线并分析比较粉土的静力荷载下抗液化强度,结果表明：随着围压的增加土体破坏时轴向应力差峰值也将增加,即饱和粉土的抗剪强度随着围压的增加而增加,且压缩模量也随之增大。(3)将动三轴试验结果、静三轴试验结果与标准贯入试验结果进行分析比较,找出室内试验与现场测试结果判定粉土抗液化强度的变化规律性,试验分析表明：动三轴试验、静三轴试验均能较好反映同种土体在不同围压下的抗液化能力；动三轴试验能较好反映不同土体间的抗液化能力；动三轴试验结果与标准贯入试验结果较吻合。
[Abstract]:Earthquake is a sudden natural disaster of people's life and property, which causes great economic loss, casualties and human heart pain to human beings. Especially in the era of rapid economic development, urbanization is developing rapidly. With a high concentration of population and material finances, the damage caused by modern earthquakes will be even greater. A large number of earthquake damage experiences show that the liquefaction instability of silt under dynamic load is an important factor of ground damage caused by earthquake. Silt is a kind of transitional soil, which is between sand and clay. It contains three kinds of granular components: sand, silt and clay, among which clay and silt are called fine grains. The engineering properties of silt are different from clay and sand. In this paper, the dynamic triaxial test and static triaxial test are carried out on the silt foundation of actual engineering in Yangzhou area, and the results of indoor test and standard penetration test are compared and analyzed. The main contents are as follows: (1) through DDS-70 microcomputer controlled electromagnetic vibration triaxial test on silt dynamic triaxial consolidation and undrained test, the relationship between dynamic shear strength and failure vibration times and related curves are obtained. The results show that the larger the confining pressure of the same soil is, The larger the dynamic shear stress value is, the stronger the liquefaction resistance of the soil sample is, that is, the larger the dynamic shear stress value 蟿 d, the stronger the liquefaction resistance of the soil sample. It can be seen that increasing the confining pressure can improve the liquefaction resistance of saturated silty soil. (2) the static triaxial consolidation drainage test of silty soil is carried out by strain-controlled static triaxial apparatus. The relative failure curves are obtained and the liquefaction strength of silt under static load is analyzed and compared. The results show that the peak value of axial stress difference increases with the increase of confining pressure, that is, the shear strength of saturated silt increases with the increase of confining pressure. And the compression modulus also increases with it.) the dynamic triaxial test results, static triaxial test results and standard penetration test results are analyzed and compared, and the results of indoor and field tests are found to determine the regularity of variation of silt liquefaction strength. The test results show that the dynamic triaxial test and static triaxial test can better reflect the liquefaction resistance of the same soil under different confining pressures, and the dynamic triaxial test can better reflect the liquefaction resistance of different soils. The dynamic triaxial test results are in good agreement with the standard penetration test results.
【学位授予单位】：扬州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU411.8

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