不同冲击荷载下高温-水冷却花岗岩能量耗散特征研究
Energy dissipation characteristics of high-temperature granites after water-cooling under different impact loadings
武东阳 1蔚立元 1张涛 1苏海健 1鞠明和 1王德荣 2郑春梅3
作者信息
- 1. State Key Laboratory for Geomechanics and Deep Underground Engineering(China University of Mining and Technology),Xuzhou 221116,China
- 2. State Key Laboratory of Disaster Prevention and Mitigation of Explosion and Impact(Army Engineering University of PLA),Nanjing 210007,China
- 3. School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China
- 折叠
摘要
研究地热钻井施工中高温岩石冷却后的能量耗散特性,对提高岩石破碎效率至关重要.通过对分离式霍普金森压杆(SHPB)系统在不同冲击载荷下的动态试验,研究了高温-水冷却花岗岩的能量耗散特性.花岗岩的加热范围为25℃至1000℃.此外,还通过电镜扫描(SEM)和压汞试验(MIP)获得了该花岗岩的微观形貌和孔隙分布.以400℃为界,孔隙分布变化趋势可分为两个阶段:在400℃之前,微孔和小孔占比超过75.00％;当T≥400℃时,中孔占比迅速增加.此外,动态峰值应力和峰值应变随入射能量的增加而增加,而动态弹性模量的变化趋势不明显.当加热温度从25℃增加到800℃时,耗散能占比呈上升趋势,而加热到1000℃的花岗岩的吸收能量下降.当应变率在100 s−1−120 s−1之间时,能量利用效率最高.
Abstract
Studying the energy dissipation characteristics of high-temperature rock after cooling with water during geothermal drilling construction is crucial to improving rock crushing efficiency. The energy dissipation characteristics of granite were investigated by conducting dynamic tests with a split Hopkinson pressure bar (SHPB) system under different impact loadings. The granite specimens were subjected to temperatures from 25 ℃ to 1000 ℃. The micromorphology and pore distribution of granite were obtained by scanning electron microscopy (SEM) and mercury intrusion porosimetry (MIP) tests. The porosity change trend could be divided into two stages at 400 ℃. The micropores and small pores accounted for over 75.0％ before 400 ℃. The medium pore proportion increased rapidly when T≥400 ℃. In addition, the dynamic peak stress and peak strain increased with incident energy, while the trend of the change in the dynamic elastic modulus was not apparent. The proportion of dissipated energy showed an upwards trend when the heating temperature varied from 25 ℃ to 800 ℃, while the absorbed energy of granite heated to 1000 ℃ decreased. The energy utilization efficiency was the highest when the strain rate was between 100 s−1 and 120 s−1.
关键词
岩石力学/高温-水冷却处理/微观结构/动力学特性/能量耗散特征Key words
rock mechanics/heating and water-cooling/microstructure/dynamic properties/energy dissipation引用本文复制引用
基金项目
National Natural Science Foundation of China(52179118)
National Natural Science Foundation of China(42077240)
National Natural Science Foundation of China(52104101)
Scientific and Technological Research Program of Chongqing Municipal Education Commission,China(KJQN201900727)
出版年
2023
NETL
NSTL
维普
万方数据