| 动荷载和含水率对红砂岩破坏及能耗特性的影响 |
| |
| 引用本文： | 金解放,徐 虹,余 雄,廖占象.动荷载和含水率对红砂岩破坏及能耗特性的影响[J].岩土力学,2022,43(12):3231-3240. |
| |
| 作者姓名： | 金解放 徐 虹 余 雄 廖占象 |
| |
| 作者单位： | 江西理工大学 土木与测绘工程学院，江西 赣州 341000 |
| |
| 基金项目： | 国家自然科学基金（No.51964015，No.52174112）；江西理工大学清江青年英才支持计（No.JXUSTQJBJ2017007） |
| |
| 摘 要： | 地下工程岩体爆破开挖过程中，动荷载和地下水对工程岩体的安全稳定具有显著影响。为研究动荷载和含水率对岩体破坏和能耗特性的影响，利用改进的SHPB试验装置，设置4个冲击速度和6个含水率等级，对红砂岩进行动态冲击试验。通过分析不同含水率工况下能量反射率、透射率和耗散率的变化规律，构建红砂岩能耗特性与含水率的经验模型；对破坏试样进行筛分试验，根据破碎分形理论，研究岩石破碎分形维数随含水率的变化规律。结果表明：（1）同一冲击速度下，能量透射率和含水率具有指数函数关系且呈负相关，能量耗散率随含水率先增大后减小且具有二次函数关系；（2）同一含水率下，能量透射率和冲击速度呈负相关，能量耗散率和冲击速度呈正相关；（3）在出现宏观破坏的试样中，红砂岩的破坏程度随含水率的增加而增大，且在含水率为1%处出现拐点，破碎分形维数和含水率具有指数函数关系。
|
| 关 键 词： | 红砂岩 冲击速度 含水率 能耗特性 分形维数 |
| 收稿时间： | 2021-12-19 |
| 修稿时间： | 2022-02-18 |
Effect of dynamic load and water content on failure and energy dissipation characteristics of red sandstone |
| |
| JIN Jie-fang,XU Hong,YU Xiong,LIAO Zhan-xiang.Effect of dynamic load and water content on failure and energy dissipation characteristics of red sandstone[J].Rock and Soil Mechanics,2022,43(12):3231-3240. |
| |
| Authors: | JIN Jie-fang XU Hong YU Xiong LIAO Zhan-xiang |
| |
| Institution: | School of Civil and Surveying Engineering, Jiangxi University of Science and Technology, Ganzhou, Jiangxi 341000, China |
| |
| Abstract: | Dynamic load and groundwater have a significant influence on the safety and stability of engineering rock mass during underground blasting excavation. In order to study the influence of dynamic load and water content on the failure and energy dissipation characteristics of rock mass, dynamic impact tests including four impact velocities and six water content levels on red sandstone were carried out with an improved SHPB test device. By analyzing the variation laws of energy reflectivity, transmissivity, and dissipation rate under different water contents, an empirical model representing the relationship between energy dissipation characteristics and water content of red sandstone was established. Screening tests were conducted on specimen fragments, and the variation law of fractal dimension of rock fracture with water content was studied according to the fractal theory. The results show that: 1) Under the same impact velocity, the energy transmissivity and water content have an exponential function relationship and a negative correlation, the energy dissipation rate increases first and then decreases with the increasing water content, and they have a quadratic function relationship. 2) Under the same water content, the energy transmissivity is negatively correlated with the impact velocity, while the energy dissipation rate is positively correlated with the impact velocity. 3) For the specimens with macroscopic failure, the failure degree of red sandstone increases with the increase of water content, with a turning point at the water content of 1%, and the fracture fractal dimension has an exponential function relationship with water content. |
| |
| Keywords: | red sandstone impact velocity water content energy dissipation fractal dimension |
|
| 点击此处可从《岩土力学》浏览原始摘要信息 |
| 点击此处可从《岩土力学》下载免费的PDF全文 |
|
