戴俊, 刘博源.冲击荷载下含孔洞花岗岩动态力学特性研究[J].河南理工大学学报（自然科学版）,2025,44(3):172-180.

DAI J, LIU B Y. Dynamic mechanical properties of granite containing holes under impact loading[J]. Journal of Henan Polytechnic University(Natural Science) , 2025, 44(3): 172-180.

冲击荷载下含孔洞花岗岩动态力学特性研究

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 施工过程中，隧道开挖、矿山深部巷道开挖等受冲击荷载扰动区域内的含孔洞缺陷围岩会发生破坏，本文开展含孔洞花岗岩在冲击荷载下的动力学特性和破坏过程研究。  方法 利用水刀切割机制备含不同孔径孔洞的花岗岩试样，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，采用高速摄影机记录试样破坏过程，分析冲击荷载作用时孔洞尺寸对花岗岩动态力学性能和破坏过程的影响。  结果 结果表明：随着孔径增大，试样动态抗压强度降低、峰值应变增大；孔洞大小与试样的单位吸收能、单位反射能正相关，与透射能力负相关；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越强，对水平裂缝的先促进后抑制作用越明显，应力波在试样中传播时被吸收的能量越多，试样内部裂隙的开展速度越快，破坏时产生的碎屑越多。对于小孔径试样，增大孔径对应变的影响小于对强度的影响；对于大孔径试样，增大孔径对应变的影响大于对强度的影响；小孔径试样的破坏过程与孔径关系较小，孔径越大，对主要裂缝的诱导能力越明显，对水平裂缝的先促进后抑制作用越明显。虽然破坏前小孔径试样可承受更大的压力，但破坏前的预兆更少，更接近脆性破坏，大孔径试样更接近延性破坏。  结论 本研究揭示了不同孔径尺寸对含孔洞花岗岩动态抗压强度变化规律、能量耗散机制及破坏模式影响，为深部工程冲击扰动区围岩稳定性评估与防爆支护设计提供了理论参考。

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:国家自然科学基金资助项目（51174159）；陕西省自然科学基础研究计划项目（2017JQ5069）；陕西省专项科学研究基金项目（15JK1471）

收稿日期:2024/07/29

修回日期:2024/09/30

出版日期:2025-04-18

Dynamic mechanical properties of granite containing holes under impact loading

DAI Jun, LIU Boyuan

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

Abstract: Objectives The study aims to investigate the dynamic mechanical behavior and failure mechanisms of granite containing cavities under impact loading， a critical issue during tunnel excavation and deep mine roadway development， where rock masses with voids are prone to dynamic disturbance-induced failure.  Methods Granite specimens with different hole diameters were fabricated using waterjet cutting. Impact tests were conducted using a 50 mm diameter split Hopkinson pressure bar （SHPB） system. A dynamic strain gauge recorded the stress-strain data， and a high-speed camera captured the failure process. The effects of hole size on dynamic mechanical properties and failure modes were analyzed. Results As hole diameter increases， the dynamic compressive strength decreases， while the peak strain increases. Hole diameter shows a positive correlation with both specific absorbed energy and specific reflected energy， and a negative correlation with transmitted energy. Larger holes induce more prominent major cracks and exhibit a clearer trend of promoting and then inhibiting horizontal crack propagation. More stress wave energy is absorbed， accelerating internal fracture development and producing more debris upon failure. In small-hole specimens， strength is more sensitive to hole size than strain， while in large-hole specimens， strain is more sensitive. Small-hole specimens endure higher stress before failure but exhibit fewer precursors， resembling brittle failure， whereas large-hole specimens demonstrate behavior closer to ductile failure.  Conclusions This study reveals how hole size affects the dynamic compressive strength， energy dissipation behavior， and failure evolution of granite under impact loading. These findings provide theoretical support for evaluating surrounding rock stability and designing anti-blast support systems in deep underground engineering.

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