戴俊,刘博源.冲击荷载下含孔洞花岗岩的动态力学特性研究[J].河南理工大学学报(自然科学版)，doi:10.16186/j.cnki.1673-9787.2024070095.

DAI J , LIU B Y． Study on the dynamic mechanical properties of granite with holes under impact loading[J]. Journal of Henan Polytechnic University( Natural Science) ，doi: 10.16186/j.cnki.1673-9787.2024070095.

冲击荷载下含孔洞花岗岩的动态力学特性研究(网络首发)

戴俊，刘博源

西安科技大学 建筑与土木工程学院，陕西 西安 710000

摘要: 目的 为了探究含贯通孔洞花岗岩在冲击荷载下的动力学特性与破坏过程。 方法 利用水刀切割机制备含不同孔径的花岗岩试件，使用杆径为50 mm的分离式霍普金森压杆装置进行冲击试验，通过超动态应变仪记录实验数据，采用高速摄影机对试样破坏的过程进行记录，分析冲击荷载作用时孔洞尺寸对花岗岩动态力学性能与破坏过程的影响。 结果 研究结果表明：随着孔洞增大，试件动态抗压强度降低、峰值应变增大。孔洞大小和试样的单位吸收能与单位反射能呈正相关的关系与透射能力呈负相关的关系；在试样破坏过程中，直径越大的孔洞对主要裂缝的诱导能力就越强，对水平裂缝的先促进后抑制的现象就越明显，应力波在试件中传播时被吸收的能量就越多，试样内部裂隙的开展速度就越快，破坏时产生的碎屑也越多。结论 对于小孔径试样，增大孔径对应变的影响要小于对强度的影响，对于大孔径试样，增大孔径对应变的影响要大于对强度的影响，对于小孔径试样，其破坏过程与孔径关系较小，孔径越大其对主要裂缝的诱导能力就越明显，对水平裂缝的先促进后抑制的现象就越明显。虽然小孔径试样在破坏前可承受更大的压力，但破坏前的预兆更小，更接近脆性破坏，大孔径试样更接近延性破坏。研究成果可为巷道及隧道在开挖或受灾时围岩的稳定性与破坏过程提供参考价值。

关键词:孔洞花岗岩；破坏机制；能量分析；冲击荷载；动力学特性

doi: 10.16186/j.cnki.1673-9787.2024070095

基金项目:国家自然科学基金(51174159)

收稿日期：2024-07-29

修回日期：2024-08-26

网络首发日期：2025-02-19

Study on the dynamic mechanical properties of granite with holes under impact loading (Online)

DAI Jun, LIU Boyuan

Faculty of Architecture and Civil Engineering,Xi’an University of Science and Technology, Xi’an 710000, Shaanxi, China

Abstract: Objectives To explore the dynamic characteristics and failure processes of granite with through-holes under impact loading. Methods granite specimens with different hole diameters were prepared using a waterjet cutting mechanism. Impact tests were conducted using a split Hopkinson pressure bar device with a rod diameter of 50 mm. Experimental data were recorded using a super dynamic strain gauge, and a high-speed camera was used to capture the failure process of the specimens. The influence of hole size on the dynamic mechanical properties and failure processes of granite under impact loading was analyzed. Results The study results indicate that as the hole size increases, the dynamic compressive strength of the specimens decreases, and the peak strain increases. There is a positive correlation between hole size and both the specific absorbed energy and specific reflected energy, while the transmission capability shows a negative correlation. During the specimen failure process, larger hole diameters exhibit a stronger ability to induce major cracks, with a more pronounced phenomenon of initially promoting and then inhibiting horizontal cracks. More energy is absorbed when stress waves propagate through the specimen, leading to a faster development of internal fractures and the generation of more debris upon failure. Conclusions For small-diameter specimens, increasing the hole size has a smaller effect on strain than on strength. For large-diameter specimens, increasing the hole size has a greater effect on strain than on strength. The failure process of small-diameter specimens is less related to the hole size, while larger hole sizes more clearly induce major cracks and show a more pronounced phenomenon of initially promoting and then inhibiting horizontal cracks. Although small-diameter specimens can withstand greater pressure before failure, they exhibit fewer pre-failure signs and are closer to brittle failure. Large-diameter specimens are closer to ductile failure. The research findings provide valuable references for the stability and failure processes of surrounding rock in tunnels and underground spaces during excavation or disaster events.

Key words: porous granite; impact load; energy analysis; failure mechanism; dynamic characteristics