振动频率对LCES动力特性的影响分析及其机理初探  

Cyclic loading frequency effect and mechanism of lightweight clay-EPS beads soil

作　　者：黎冰[1,2,3] 高玉峰[1,2] 丰土根[1,2] 

机构地区：[1]岩土力学与堤坝工程教育部重点实验室,南京210098 [2]河海大学岩土工程研究所,南京210098 [3]东南大学土木工程学院,南京210096

出　　处：《岩土力学》2008年第10期2731-2734,2740,共5页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.50479020);江苏省青蓝工程项目;教育部留学回国人员基金项目资助

摘　　要：通过室内动三轴试验研究了0.02Hz,0.1Hz,1.0Hz3种振动频率对黏土与EPS颗粒混合轻质土(LCES)动力特性的影响。结果表明,振动频率对LCES的动力特性有明显的影响,当振动频率在0.02～1.0Hz范围内变化时,随着振动频率的降低,试样的轴向动应变和阻尼比增大,动强度和动模量减小。和小频率加载相比,大频率加载情况下的孔压发展较慢,即有效应力相对较大,所以动应变越小而动强度越大。最后,从平均加载速率的概念出发,讨论了振动频率对土动力特性的影响。Based on a series of dynamic triaxial tests in which the frequency is equals to 0.02 Hz, 0.1 Hz, 1.0 Hz, the effect of cyclic loading frequency on the lightweight clay mixed with EPS beads soil （LCES） is investigated. The results of dynamic triaxial tests show that the cyclic loading frequency has obvious effect on the LCES, with the decreasing cyclic loading frequency, axial strain and damping ratio increase, dynamic strength and dynamic modulus decrease when cyclic loading frequency equals to 0.02-1.0 Hz. Compared with high cyclic loading frequency, the pore water pressure at low cyclic loading frequency develops more quickly, and the effective confining pressure of LCES decreases quickly at the same time, which leads to the destruction of LCES, so the dynamic strain increases and the dynamic strength decreases accordingly.

关 键 词：黏土与EPS颗粒混合轻质土 动三轴试验 振动频率 动力特性 机理 

分 类 号：TU435[建筑科学—岩土工程]