中南大学学报（自然科学版）2024，Vol.55Issue(4)：1433-1446,14.DOI:10.11817/j.issn.1672-7207.2024.04.016
高功率激光水平辐照花岗岩致裂成孔特性及成孔能效评价
Evaluation of characteristics and energy efficiency of granite cracking induced by high power laser horizontal irradiation
摘要
Abstract
In view of the current engineering problems of slow drilling speed and large bit loss in the construction of hard rock tunnel by drilling and blasting method,the project idea of using high power laser horizontal irradiation of hard rock to quickly form holes instead of traditional PDC bit drilling was proposed.Feasibility test of granite perforation by high power laser horizontal irradiation was carried out to analyze the cracking characteristics of granite irradiated by high power laser horizontal irradiation.Uniaxial compression test,scanning electron microscope(SEM-EDS)and X-ray diffractometer(XRD)were used to analyze the mechanical properties and microscopic phase evolution of rock before and after laser action.The rock breaking velocity and specific energy of laser perforating and PDC bit drilling were compared comprehensively.The results show that"explosion-like crater"is formed on the rock surface after continuous laser irradiation,and the molten material accumulates at the bottom of the hole under the action of gravity,absorbes most of the laser energy at the bottom of the hole,and inhibites the thermal cracking reaction of the rock at the bottom of the hole.The longitudinal failure of rock is affected by gravity,and the distribution of molten material in the upper and lower pore walls is uneven.With the continuous irradiation of laser,the center of rock pore will continuously deviate from the incident point of light spot.The uniaxial compressive strength of rock samples decreases from 63.31 MPa to 42.36 MPa after being irradiated by 4.5 kW laser for 10 s,which is due to the increase of biomica mass fraction caused by the decomposition of albiar.The rock breaking speed and specific energy of 4.5 kW laser perforation increase by 95.03%and 15.3%compared with those of PDC bit drilling,which proves the effectiveness of high power laser horizontal irradiation of hard rock perforation.关键词
隧道工程/激光破岩/成孔特性/热裂特性/成孔能效Key words
tunnel engineering/laser rock breaking/pore-forming characteristics/thermal cracking characteristics/pore-forming efficiency分类
交通工程引用本文复制引用
李梓焜,张学民,武朝光,陈治亚,乔世范,王树英..高功率激光水平辐照花岗岩致裂成孔特性及成孔能效评价[J].中南大学学报（自然科学版）,2024,55(4):1433-1446,14.基金项目
国家自然科学基金资助项目(52378425) （52378425）
中南大学中央高校基本科研业务费专项资金资助项目(2022374)(Project(52378425)supported by the National Natural Science Foundation of China （2022374）
Project(2022374)supported by the Fundamental Research Funds for the Central Universities of Central South University) （2022374）
