冻融循环下海相黏土变形特性试验研究  

Experimental study on the deformation characteristics of marine clay under freeze-thaw cycles

作　　者：韩昱 李永升 张亚辉 王育林 刘俊伟[1] HAN Yu;LI Yongsheng;ZHANG Yahui;WANG Yulin;LIU Junwei(School of Civil Engineering,Qingdao University of Technology,Qingdao 266525,China;Qingdao Zhonghang Engineering Testing and Testing Co.,Ltd.,Qingdao 266031,China)

机构地区：[1]青岛理工大学土木工程学院,青岛266525 [2]青岛中航工程试验检测有限公司,青岛266031

出　　处：《青岛理工大学学报》2025年第1期8-15,33,共9页Journal of Qingdao University of Technology

基　　金：山东省优秀青年基金(ZR2021YQ31);国家自然科学基金(42277135)。

摘　　要：冻融循环作为影响海相黏土动力学特性的关键劣化因素,其影响机制亟待深入探究。为探究冻融循环作用下海相黏土的动力特征规律,针对重塑黏土开展一系列不排水循环单剪试验,研究了冻融循环次数与冻融循环温度对海相黏土动力特性的影响。研究表明:相同冻融条件下,循环应力比的增加,导致应变变化速度加快,达到破坏应变所需要的次数降低;冻融循环次数的增加与冷端温度的降低导致土体内部结构发生破坏,使土样破坏振次提前、软化速度加快,经历5次冻融循环后变化幅度降低趋于稳定;基于试验结果建立了冻融循环次数与破坏振次的函数关系;在大循环应力比下,冻融循环作用对循环剪切软化的影响相对较小。Freeze-thaw cycles,as a critical deteriorating factor affecting the dynamic characteristics of marine clay,urgently demands further exploration into its underlying mechanisms.To investigate the dynamic characteristics of marine clay under freeze-thaw cycles,a series of undrained cyclic simple shear tests were conducted on remolded clay to study the effects of the number and temperature of freeze-thaw cycles on the dynamic characteristics of marine clay.The research findings indicate that under constant freeze-thaw conditions,an increase in the stress cycle ratio leads to accelerated strain rates and a lower number of cycles required to reach failure strain.Additionally,as the number of freeze-thaw cycles increases and the cold-end temperature decreases,there is microstructural damage within the soil,resulting in earlier failure vibrations and accelerated softening.However,after five freeze-thaw cycles,the magnitude of these changes stabilizes.A functional relationship between the number of freeze-thaw cycles and failure vibrations has been established based on the test results.It is also observed that the softening behavior of soil becomes less sensitive to freeze-thaw cycles under high stress cycle ratios.

关 键 词：海相黏土 冻融循环 应力-应变滞回曲线 破坏振次 软化指数 

分 类 号：TU411.6[建筑科学—岩土工程] TU447[建筑科学—土工工程]