摘要
干湿循环效应是影响红层泥岩库区边坡稳定性的重要因素。为研究原状风化泥岩在干湿循环过程中的力学和裂隙演化特征,开展了三轴固结不排水剪切试验、CT扫描及高精度扫描电镜试验。结果表明,红层泥岩在低围压下的应力-应变关系呈应变软化特征,在高围压下呈应变硬化特征,抗剪强度指标随干湿循环次数逐渐下降;红层泥岩的裂隙体积含量随循环次数增加呈指数型衰减,且与粘聚力呈负线性相关的函数关系;泥岩的微观结构在干湿循环过程中逐渐破坏,导致裂隙的连通和力学性能衰减。
Dry-wet cycle effect is an important factor affecting slope stability in red mudstone reservoir area.Triaxial consolidation undrained shear experiments,CT scans and high precision scanning electron microscopy experiments were carried out to investigate the mechanical and fracture evolution characteristics of in situ weathered mudstones during dry and wet cycles.The results show that the stress-strain relationship of red-bed mudstone presents strain softening characteristics at low confining pressures and strain hardening characteristics at high confining pressures.The shear strength parameters of red-bed mudstone decrease gradually during the dry-wet cycle.The volume content of cracks decreases exponentially with the increase of the time of dry-wet cycles,and has a negative linear correlation with cohesion function.The microstructure of mudstone gradually breaks down in the process of dry-wet cycles,leading to the connectivity of cracks and the attenuation of mechanical properties.
作者
王天奇
葛新
WANG Tian-qi;GE Xin(College of Civil Engineering,Tongji University,Shanghai 200092,China;State Key Laboratory of Hydroscience and Engineering,Tsinghua University,Beijing 100091,China)
出处
《水电能源科学》
北大核心
2023年第10期163-166,共4页
Water Resources and Power
基金
国家自然科学基金项目(52378532)。
关键词
红层泥岩
干湿循环
三轴剪切试验
裂隙
red mudstone
dry and wet cycle
triaxial shear test
fissure
