有荷条件下石灰处治膨胀土干湿循环试验研究  

Experimental Study on Lime-Treated Expansive Soil Subjected to Wetting and Dissecting Cycles Under Axial Stress

作　　者：赵克烈[1] ZHAO Kelie(China Railway Major Bridge Reconnaissance&Design Institute Co.Ltd.,Wuhan 430050)

机构地区：[1]中铁大桥勘测设计院集团有限公司,武汉430050

出　　处：《土工基础》2021年第1期81-85,共5页Soil Engineering and Foundation

摘　　要：由环境变化引起的土体湿度变化对路基土,特别是石灰改性膨胀土的影响,近年来引起了广泛的关注。使用能定量控制土体含水率变化且能提供稳定轴向压力的装置,对石灰改性膨胀土样进行了最高四次的干湿循环试验。同时使用传统的风干、喷水干湿循环方法进行了对比试验。随后,对经历干湿循环后的试样使用GDS动态三轴试验仪进行了累积塑性应变测试。通过试验发现,干湿循环装置提供的轴压和侧限显著降低了由干湿循环引起的石灰改性膨胀土试样的性质劣化。试验结果表明,土样的赋存状态在分析干湿循环对土样的影响时不可忽略。The influence of moisture variation induced by the environmental change on subgrade soils,especially on the limetreated expansive soils,has increasingly received attentions in the engineering practices.However,the contact pressures applied on the subgrade soils induced by the super structures are generally ignored in the evaluation of the wetting and dissecting cycles on the expansive soil performances.An innovative device that can provide constant axial pressure and lateral restraint,as well as precisely control the variation of moisture content of soil samples,was used in testing of the wetting and dissecting process of lime-treated expansive soil samples.In addition,the conventional method that dries sample in the air and wets sample by springing water were also utilized for comparative study.The GDS dynamic triaxial test equipment was used to test the accumulative axial strain of the samples that experienced different times of wetting and dissecting cycles.It is observed that,under the axial pressure and lateral restraint provided by this innovative device can effectively reduce the damage on samples induced by wetting and dissecting cycles.The results show that the stress state of subgrade soil cannot be ignored when studying the impact of wetting and dissecting cycles.

关 键 词：石灰改性膨胀土 干湿循环 轴载 累积塑性应变 

分 类 号：TU411[建筑科学—岩土工程]