摘要
利用远距光学显微镜对重塑膨胀土中在自然风干条件下的裂隙发展变化进行了动态的、定量的观测,对不同裂隙发育程度的膨胀土进行了不排水、不排气的非饱和三轴多级剪切试验。试验结果表明,裂隙图像的灰度熵可以很好地表征裂隙的发育发展程度,适合作为膨胀土裂隙发育程度的度量指标。环境温度较高、湿度较低有利于膨胀土中裂隙的发育发展。膨胀土中裂隙发展是一个长期的、渐进的过程,初期裂隙发展速度较快,后期大大减缓。裂隙膨胀土的强度指标与饱和度和裂隙度呈线性关系,土体裂隙不发育时,饱和度是影响强度的主导因素,而饱和度较低时,裂隙对膨胀土强度的影响占主导地位。
The development of remolded expansive soils was measured by using long distance microscope system under the condition of natural air-dried. The un-drained and triaxial multi-stage shear tests for various soil samples containing different amounts of fissure were carried out. The result shows that the gray level entropy of observed pictures can well describe the development degree of fissures. The development of fissures is a long-term gradual process. The fissures develop rapidly at the beginning but remarkably slow down in l-2 days. The strength parameters of expansive soils are linearly related to the saturation degree and fissure development degree. In case the development of fissures is weak the saturation of soils may strongly affect the strength of soil. But fissure is the primary factor affecting the strength of soil with low saturation.
出处
《水利学报》
EI
CSCD
北大核心
2004年第6期108-113,共6页
Journal of Hydraulic Engineering
关键词
膨胀土
裂隙
远距光学显微镜
灰度熵
裂隙度
强度
expansive soils
fissures
long distance microscope system
gray level entropy
fissure development degree
strength
