摘要
为研究岩爆等地质灾害发生的力学机制,利用改进的霍普金森杆试验装置,对红砂岩进行预加载三维静应力下受冲击载荷试验,分析红砂岩的破坏形态、能量耗散规律及变形强度特征.研究表明,红砂岩的破坏形态在有无围压情况下,都随着轴压的增大破坏程度增大,在无围压及有围压情况下分别呈现出"X"型和"圆锥台"型的压剪破坏形态.当轴压固定时,红砂岩的破坏程度随围压的增大而降低.在三维动静组合加载下,红砂岩入射能及单位体积吸收能与平均应变率呈线性递增关系,且递增的程度随轴压的增大表现出先增大后降低的趋势,而随围压的增大而增大.红砂岩应力应变曲线在不同平均应变率下表现出应变回弹、应力跌落及峰后塑性三种类型.红砂岩抗压强度增长因子与平均应变率1/3次幂呈线性递增关系.
In order to investigate the mechanical system of geologic disaster such as rock burst,preload 3D static stress and impact load test of red sandstone is performed with a modified 3D split Hopkinson pressure bar（ SHPB） apparatus. The variation rule of red sandstone on failure mode,dissipation of energy and deformation strength feature is then analyzed. The results show that damage of the red sandstone is increased with increasing axial pressure,regardless of the presence of confining pressure. The red sandstone shows ＂X＂type and cone shape compression- shear failure mode under the condition of confining pressure and confining pressure- free.When the axial pressure is constant,damage of the red sandstone is decreased with increasing confining pressure. Incident energy and the energy absorption per unit have a good linear positive correlation with average strain rate increasing,the increasing degree is increased at first then decreased as the axial pressure is increased,but increased with the increasing confining pressure. Stress- strain curve of red sandstone shows three types of strain,namely,rebound,stress drop and post- peak plastic under different average strain rates. There is a linear increasing correlation between the compressive strength growth factor and a third power of average strain rate.
出处
《昆明理工大学学报（自然科学版）》
CAS
2016年第4期33-37,58,共6页
Journal of Kunming University of Science and Technology(Natural Science)
基金
国家自然科学基金项目(41362013
51304087)
关键词
岩爆
霍普金森杆
三维动静组合加载
破坏形态
平均应变率
rock burst
split Hopkinson pressure bar（SHPB）
3D coupled static and dynamic loads
failure mode
average strain rate
