TD 262; TU752
Anhui University of Science and Technology
为了研究不同冻结温度(-10~-30 ℃)的冻土在冲击载荷作用下的能量耗散与破坏特征,利用75 mm杆径的分离式Hopkinson压杆,对冻土试件进行不同冲击气压(0.2~0.7 MPa)的动态压缩实验。结果表明：冻土试件的破碎耗能密度与入射能量呈线性正相关,在冻结温度降至-20 ℃后增幅明显提高且增长速率趋于稳定；破碎耗能密度与冻结温度呈线性负相关,而与应变率呈二次多项式关系；冻土破碎耗能密度与动态抗压强度近似于线性关系,直观反映其在冲击载荷作用下的强度本质特征；破碎耗能密度越大,破碎效果越显著；冻土试件的破碎程度可以通过分形维数来定量评估,其值主要集中在1.5~2.4之间,试件破碎程度越高则分形维数越大,且分形维数与破碎耗能密度存在线性正相关关系。
In order to study the energy consumption and failure characteristics of frozen soil with different freezing temperatures (-10~-30 ℃) under impact loads, the dynamic compression experiments of frozen soil samples under different impact pressures (0.2~0.7 MPa) were carried out with a 75 mm separate Hopkinson pressure bar experiment apparatus. The results show that the crushing energy consumption density of frozen soil samples is linearly and positively correlated with the incident energy. After the freezing temperature drops to -20 ℃, the increase rate increases significantly and the growth rate tends to be stable; The crushing energy consumption density has a linear negative correlation with freezing temperature, but a quadratic polynomial relationship with strain rate; The dynamic compression strength of frozen soil is approximately linearly positively correlated with the crushing energy consumption density, which can better reflect the essential characteristics of the strength of frozen soil samples under external load; The larger the energy consumption density of frozen soil sample is, the more significant the crushing effect is; The fractal dimension can be used to quantitatively assess the crushing degree of frozen soil, and its value is mainly concentrated between 1.5-2.4, the higher the degree of fragmentation of the specimen, the greater the fractal dimension, and there is a linear positive correlation between the fractal dimension and the crushing energy consumption density.
程 虎,李重情,束玲玲,等. 冲击载荷作用下人工冻土的破碎能耗特征[J]. 科学技术与工程, , ():复制