卸荷与干湿循环联合效应下巴东组泥质粉砂岩膨胀特性研究  

Expansion Characteristics of Clayey Siltstone of the Badong Formation Under the Combined Effects of Unloading and Dry-Wet Cycling

作　　者：赵二平[1,2] 蒋尚家 章涵 向国梁 张聪 车德龙 ZHAO Erping;JIANG Shangjia;ZHANG Han;XIANG Guoliang;ZHANG Cong;CHE Delong(Key Laboratory of Geological Hazards in Three Gorges Reservoir Area,Ministry of Education(China Three Gorges University),Yichang 443002,China;College of Civil Engineering and Architecture,China Three Gorges University,Yichang 443002,China)

机构地区：[1]三峡库区地质灾害教育部重点实验室(三峡大学),湖北宜昌443002 [2]三峡大学土木与建筑学院,湖北宜昌443002

出　　处：《三峡大学学报(自然科学版)》2025年第2期62-68,共7页Journal of China Three Gorges University:Natural Sciences

基　　金：国家自然科学基金项目(U2034203)。

摘　　要：为了研究泥质粉砂岩在卸荷与干湿循环联合效应下的膨胀特性,开展了不同卸荷条件下的干湿循环试验,通过核磁共振揭示了不同卸荷条件下试样内部孔隙演变规律.基于Huder-Amberg本构修正建立了考虑卸荷损伤与干湿循环次数的泥质粉砂岩膨胀本构模型并验证了其合理性.研究结果表明:随着干湿循环次数增加,试样膨胀率先增加后减小,在第4次循环时达到最大值;由于中、小孔隙在干湿循环后大幅度减少,大孔隙仅有少量增加,导致孔隙率随着干湿循环次数增加而减小;随着卸荷量增加,试样膨胀率减小,卸荷量和干湿循环次数的增加均会加剧岩样内部损伤程度,导致孔隙度下降,其中卸荷量的影响程度更大.In order to study the swelling characteristics of muddy siltstone under the combined effect of unloading and wet/dry cycling,the wet/dry cycling tests were carried out under different unloading conditions,and the internal pore evolution of the specimens under different unloading conditions was revealed by nuclear magnetic resonance(NMR),and an expansion model for muddy siltstone was established based on the Huder-Amberg principal modeling correction,which takes into account the unloading damage and the number of wet/dry cycling cycles and verifies its reasonableness.The results show that:with the increase of the number of wet and dry cycles,the swelling of the specimen firstly increases and then decreases,and reaches the maximum value in the fourth cycle;due to the fact that the medium and small pores are greatly reduced after the wet and dry cycles,and only a small increase in the large pores,the porosity decreases with the increase of the number of wet and dry cycles;with the increase of unloading amount,the swelling rate of the specimen decreases;and the increase of the amount of unloading and the number of wet and dry cycles will both exacerbate the damage of the sample and the unloading amount has a greater influence,which leads to the decrease of porosity.

关 键 词：泥质粉砂岩 卸荷 干湿循环 膨胀本构模型 结构损伤机理 

分 类 号：TU454[建筑科学—岩土工程]