长江科学院院报2017，Vol.34Issue(1)：98-103,6.DOI:10.11988/ckyyb.20150807
冻融循环条件下岩石加卸荷力学特性研究
Loading and Unloading Mechanical Characteristics of Rock under Freezing-thawing Cycles
摘要
Abstract
In order to study the mechanical loading and unloading properties of rock after freezing-thawing damage, we carried out loading-unloading test on sandstone of two different moisture contents under different freezing-thawing cycles. The results show that sandstone was damaged under the action of loading and unloading after freezing and thawing. The crack propagation direction changed,and the development of cracks intensified, especially obvous in saturated sandstones. From the point of view of the crack propagation direction and the fracture surface angle,the sandstone was dominated by shear failure under loading condition and tensile and shear failure under unloading con-dition. The damage caused by freezing and thawing indicated that the loss of peak strength and elastic modulus of sandstone increased gradually, which was slightly larger in saturated sandstone than that in natural sandstone under loading condition. Under unloading condition, the variation regularities of the unloading deformation modulus and the unloading equivalent of sandstone with different cycle times were basically consistent. The deformation modulus decreased significantly when the unloading equivalent was about 80%. The unloading deformation modulus de-creased with the increase of the freeze-thawing cycle times while unloading equivalent remained unchanged. In addi-tion,the unloading rate was so small in this paper that the influence on the deformation modulus was not obvious. The test results provide reference for the excavation of rock slope in cold region.关键词
砂岩/冻融循环/加卸荷试验/卸荷当量/变形模量/卸荷速率Key words
sandstone/freeze-thaw cycles/loading and unloading tests/unloading equivalent/deformation modulus/unloading rate分类
建筑与水利引用本文复制引用
陈招军,王乐华,王思敏,李洁,徐义根,向力..冻融循环条件下岩石加卸荷力学特性研究[J].长江科学院院报,2017,34(1):98-103,6.基金项目
水利部公益性行业科研专项经费项目(201401029) （201401029）
