冻融循环作用下砂岩三点弯曲断裂性能试验及其破坏形态研究

发布时间：2018-09-19 09:28

【摘要】：针对不同初始缝高比砂岩试样的三点弯断裂性能展开冻融循环试验研究,分析砂岩试样断裂破坏面的三维形貌随冻融循环作用的变化规律;同时,探讨试样破坏面的三维粗糙度系数与其起裂荷载、峰值荷载、断裂韧度、断裂能等参数的关系。研究结果表明:冻融循环作用对砂岩试样起裂荷载、峰值荷载、断裂韧度和断裂能有不同程度的劣化作用,其劣化作用的程度又受试样初始缝高比的影响。砂岩试样断裂面的粗糙度系数随冻融循环次数、初始缝高比的增大呈增大的趋势。当初始缝高比一定时,粗糙度系数与冻融循环次数呈较为明显的指数函数关系。冻融循环作用下,砂岩试样断裂峰值荷载的损伤因子、断裂韧度的损伤因子与粗糙度系数的增量有着较为显著的线性递增关系。
[Abstract]:According to the three-point bending fracture performance of sandstone specimens with different initial fracture-height ratio, the freeze-thaw cycle test was carried out to analyze the variation of 3D morphology of fracture failure surface with freeze-thaw cycle, and at the same time, The relationship between the three dimensional roughness coefficient of specimen failure surface and the initial crack load, peak load, fracture toughness, fracture energy and so on is discussed. The results show that the initial cracking load, peak load, fracture toughness and fracture energy of sandstone samples are affected by freezing and thawing cycles, and the degree of deterioration is affected by the initial fracture height ratio. The roughness coefficient of the fracture surface of sandstone specimen tends to increase with the number of freeze-thaw cycles and the increase of initial fracture height ratio. When the initial joint height ratio is fixed, the relationship between the roughness coefficient and the number of freeze-thaw cycles is obvious exponential function. Under the action of freeze-thaw cycle, the damage factors of fracture peak load, fracture toughness and the increment of roughness coefficient of sandstone specimen have obvious linear increasing relationship.
【作者单位】：西安理工大学土木建筑工程学院;
【基金】：国家自然科学基金资助项目(11402198)~~
【分类号】：TU45

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