饱和砂土振动液化特性受振动频率影响试验研究*
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(1 上海交通大学船舶海洋与建筑工程学院, 上海 200240;2 中国电建华东勘测设计研究院有限公司, 杭州 310014)
[摘要]为研究振动频率对饱和砂土振动液化特性的影响,采用高频振动三轴仪对饱和砂土进行不同振动频率下的振动液化试验。根据饱和砂土达到液化所需的振动时间、振动次数和振动频率三者间已有关系式,从试验数据出发,在双对数坐标系中拟合出液化时间对数与振动频率对数的线性递减关系式,避免了曲线拟合中参数确定的困难。由液化时间振动频率关系式进一步推导出液化振次振动频率关系式,在双对数坐标系中液化振次对数与振动频率对数表现为线性递增关系。利用已有文献试验数据对拟合算式进行了验证,并对拟合算式中参数的物理意义进行了阐述,此参数反映了试样初始状态、试验条件对饱和砂土的液化时间和液化振次的影响。[关键词]饱和砂土; 振动频率; 动三轴试验; 液化时间; 液化振次中图分类号:TU411.8 文献标识码:A 文章编号:1002-848X(2015)19-0076-04
Experimental study on vibration liquefaction properties of saturated sands influenced by vibration frequencyQin Zhaohui1, Deng Jianliang1, Peng Jiaqiang2, Liu Shiming2, Chen Longzhu1(1 School of Naval Architecture, Ocean & Civil Engineering, Shanghai Jiao Tong University,Shanghai 200240, China; 2 Power China Huadong Engineering Corporation Limited, Hangzhou 310014, China)Abstract: In order to study the influence of vibration frequency on the liquefaction properties of saturated sands, using the high-frequency vibration triaxial instruments, vibration liquefaction experiments on saturated sands with different vibration frequencies were carried out. According to the relationship among the vibration time and vibration numbers required for saturated sands to reach the liquefaction and the vibratory frequency, the linear decreasing relationship formula of the logarithm of the liquefied time and the vibratory frequency was obtained in the double logarithmic coordinate system by adopting the experiment data, which avoided the difficulty of the parameter choice in curve fitting. The relationship formula between the liquefied vibration numbers and the vibration frequency was further concluded based on the relationship formula between the liquefied time and the vibration frequency, the logarithm of the liquefied vibration numbers and the vibratory frequency is linear increasing in the double logarithmic coordinate system. The fitting formula was verified by existing experimental data in the literature, the physical meanings of the parameters in fitting formula were expounded, which reflected the influence of the initial state of samples and the test conditions on the time and vibration numbers required for saturated sands to reach the liquefaction.Keywords:saturated sand; vibration frequency; dynamic triaxial test; liquefied time; liquefied vibration number
*国家自然科学基金资助项目(51428901,50779034)。作者简介:秦朝辉,博士研究生,Email:qinzhaohui@sjtu.edu.cn。