多因素影响下预崩解炭质泥岩动回弹特性研究  

Dynamic resilient characteristics of disintegrated carbonaceous mudstone under the influence of multiple factors

作　　者：付宏渊[1] 杨琪毅 曾铃[1] 高乾丰 文伟 陈璐[1] Fu Hongyuan;Yang Qiyi;Zeng Ling;Gao Qianfeng;Wen Wei;Chen Lu(Changsha University of Science&Technology,Changsha 410114,China)

机构地区：[1]长沙理工大学,湖南长沙410114

出　　处：《土木工程学报》2024年第2期117-128,共12页China Civil Engineering Journal

基　　金：国家自然科学基金(51878070,51838001,52078066,52078067,52004036);湖湘青年科技创新人才(2020RC306);长沙市杰出创新青年培养计划项目(kq1905043);湖南省研究生科研创新项目(CX20210738);2021年桥梁工程安全控制教育部重点实验室开放基金(21KB12)。

摘　　要：为探究多因素影响下预崩解炭质泥岩的动回弹特性,通过动三轴试验研究偏应力、最小体应力、含水率、压实度和干湿循环次数对动态回弹模量的影响,并建立考虑上述因素影响的动回弹模量预测模型。研究表明:动回弹模量与最小体应力、压实度呈正相关关系,与偏应力、含水率呈负相关关系;在同一围压下,动回弹模量随偏应力增加而降低,降幅区间为14.1%~30.7%;含水率为6%时对应的动回弹模量最大;在围压和偏应力相同时,含水率从6%递增至10%,动回弹模量降幅区间为18.6%~35.5%;压实度从93%递增至96%时,动回弹模量增幅区间为4.47%~20.64%。采用干湿循环损伤因子表征干湿循环次数对动回弹模量的影响,发现损伤因子随干湿循环次数N增加可分为3个阶段,即快速增长阶段(N=0~1)、缓慢增长阶段(N=1~6)和增长稳定阶段(N=6~9)。各因素按显著性由高到低排序依次为:压实度、干湿循环、含水率、偏应力、最小体应力。建立的综合考虑约束效应、剪切效应、压实度、含水率和干湿循环的预测模型具有较高地准确性和适用性,可有效评估和预测湿热地区炭质泥岩路堤的动回弹模量。To investigate the dynamic resilient characteristics of disintegrated carbonaceous mudstone under the influence of multiple factors,the effects of deviator stress,minimum bulk stress,moisture content,compaction and number of wet-dry cycles on dynamic resilient modulus(MR)were investigated by dynamic triaxial tests,and a prediction model of MR considering the effects of the above factors was established.The research results show that the MR is positively correlated with the minimum bulk stress and compaction,and nega-tively correlated with the deviator stress and moisture content;under the same confining pressure,the MR decreases with the increase of deviator stress,and the decrease range is 14.1%~30.7%;the MR is the largest when the moisture content is 6%;when the confining pressure and deviator stress are the same,the moisture content increases from 6%to 10%,and the decrease range of MR is 18.6%~35.7%.When the compaction was increased from 93%to 96%,the increase of MR ranged from 4.47%to 20.64%.The damage factor of wet-dry cycles was used to characterize the effect of the number of wet-dry cycles on the MR,and it was found that the variation of damage factor could be divided into three stages with the increase of the number of wet-dry cycles N,namely,rapid growth stage(N=0~1),slow growth stage(N=1~6)and stable growth stage(N=6~9).The factors,in order of significance,are ranked as:compaction>wet-dry cycles>moisture content>deviator stress>minimum bulk stress.The prediction model,which integrates the confinement effect,shear effect,compaction,moisture content,and wet-dry cycles,has a high degree of accuracy and applicability to effectively evaluate and predict the MR of a carbonaceous mudstone embankment in humid and hot regions.

关 键 词：道路工程 预崩解炭质泥岩 干湿循环 动回弹模量 预测模型 

分 类 号：U416.1[交通运输工程—道路与铁道工程]