路基改良土循环加/卸载试验能量演化研究  

Study on Energy Evolution of Cyclic Loading/Unloading Test of Subgrade Improved Soil

作　　者：牛洪军 张俊武 章希伦 赵嘉 NIU Hongjun;ZHANG Junwu;ZHANG Xiun;ZHAO Jia(No.1 Engineering Co.,Ltd.of China First Highway Engineering Co.,Ltd.,Beijing 102205,China;Transportation Infrastructure Engineering Technology Innovation Center in Cold area of Hebei Province,Hebei University of Architecture,Zhangjiakou 075000,Hebei,China)

机构地区：[1]中交一公局第一工程有限公司,北京102205 [2]河北省寒冷地区交通基础设施工程技术创新中心、河北建筑工程学院,河北张家口075000

出　　处：《路基工程》2024年第4期69-76,共8页Subgrade Engineering

基　　金：中交一公局第一工程有限公司科技创新基金(HKY22006)。

摘　　要：通过循环加/卸载试验,分析公路路基改良土受载时的各能量参数转化规律。结果表明:不同围压下路基改良土的能量转化近似,都呈现峰前能量聚集,破坏能量耗散,峰后残余强度能量重新积聚,但效率和总量低于峰前;围压对峰前路基改良土能量参数影响较小,但少量提升了残余强度时能量聚集的作用;峰前能耗比K随轴向应变的增加而缓慢减小,当土体强度失效时,能耗比K产生突变;能耗比K突变点与应力-时间曲线拐点相对应,说明能耗比可以作为路基改良土三轴应力状态下循环加/卸载作用时的强度失效特征,也可以从能量的角度解释路基改良土的演化破坏规律。The cyclic loading/unloading test was carried out to analyze the energy parameter transformation law of the improved soil of highway subgrade under loading.The results show that the energy conversion of subgrade improved soil under different confining pressures is similar,showing pre-peak energy accumulation,failure energy dissipation,post-peak residual strength energy re-accumulation,but the efficiency and total amount are lower than pre-peak.Confining pressure has litle effect on the energy parameters of the subgrade improved soil at pre-peak,but slightly increases the effect of energy accumulation at residual strength.Before the peak,the energy consumption ratio K slowly decreases with the increase of axial strain.When the soil strength fails,the energy consumption ratio K suddenly changes.The mutational site of the energy consumption ratio K corresponds to the inflection point of stress-time curve,indicating that the energy consumption ratio can be used as the strength failure characteristic of the subgrade improved soil under cyclic loading/unloading under triaxial stress state,and can also explain the evolutionary failure law of subgrade improved soil from the perspective of energy.

关 键 词：路基改良土 循环加/卸载 径向应变 能量演化 参数比例 强度失效判据 

分 类 号：TU442[建筑科学—岩土工程]