长江科学院院报2018，Vol.35Issue(3)：1-5,12,6.DOI:10.11988/ckyyb.20171094
冻融循环作用下砂岩卸荷强度特性试验及损伤特性研究
Unloading Strength Characteristics and Damage Characteristics of Sandstone under Freeze-thaw Cycles
摘要
Abstract
Geotechnical projects in cold regions suffer from both cyclic freezing-thawing and excavation unloading, giving rise to rock degradation. In this article, the strength characteristics and damage characteristics of sandstone subjected to both cyclic freezing-thawing and excavation unloading are analyzed systematically by freeze-thaw cycle test and triaxial unloading test. The results are concluded as follows:in freeze-thaw cycle test,the sandstone expe-rienced a stage from tension failure gradually to shear failure as confining pressure rises; as the freeze-thaw cycle proceeds,the sandstone witnessed an apparent lateral expansion in the middle, with different levels of tension cracks,circular cracks,rock powder and rock fragments;while in triaxial unloading test,as freezing-thawing pro-ceeds,the peak strength of sandstone reduces,and dilatancy stress declines in an exponential relation;destructive confining pressure is in a quadratic functional relation with cycle number;moreover,the freeze-thaw damage value increases linearly with the number of freeze-thaw cycles,indicating that the effect of cyclic freezing and thawing in-tensifies gradually.关键词
砂岩/冻融循环/三轴卸荷试验/强度特性/损伤特性Key words
sandstone/freezing and thawing cycles/triaxial unloading test/strength characteristics/damage char-acteristics分类
建筑与水利引用本文复制引用
朱珍德,色麦尔江·麦麦提玉苏普,方若进,倪骁慧..冻融循环作用下砂岩卸荷强度特性试验及损伤特性研究[J].长江科学院院报,2018,35(3):1-5,12,6.基金项目
国家自然科学基金项目(41272329,51379065) （41272329,51379065）
国家自然科学基金青年基金项目(51409122) （51409122）
