硬岩地下洞室工程爆破振动与围岩损伤范围相关性研究

Correlation Study between Blasting Vibration and Surrounding Rock Damage Range of Hard Rock Underground Cavern Engineering

为了简便而准确地获取爆破荷载下硬岩地下洞室围岩损伤范围,以某待建重要地下洞室工程为研究背景,采用理论分析和数值模拟的方法,根据爆破设计方案,建立不同药量条件下多段延时爆破累积损伤计算模型,利用等效爆破荷载的方法和LS-DYNA完全重启动技术,得到多段延时爆破荷载作用下的爆破振动数据和围岩累积损伤范围。分析地下洞室围岩累积损伤效应,研究爆破振动与围岩累积损伤范围之间的相关性。研究结果表明:诱导地下洞室周边围岩损伤的荷载主要来自于二圈孔和周边孔爆破,其中洞室拱顶围岩损伤范围(2.21 m)明显大于拱腰围岩损伤范围(2.05 m);爆破全时程振动曲线的峰值处于掏槽孔延期时间范围内,与造成洞室周边围岩损伤的爆破段位不一致,应以对围岩损伤影响较大爆破段位的质点峰值振动速度研究与围岩损伤范围的相关性;建立了围岩累积损伤范围与爆破药量、爆心距和质点峰值振动速度之间的量化关系,得到了可通过任意爆心距处质点峰值振动速度推断围岩累积损伤范围的函数关系式,为控制围岩爆破损伤提供依据。

Field detection of surrounding rock damage range is cumbersome.In order to obtain the surrounding rock damage range simply and accurately,a major underground cavern project to be built is taken as the research background.Theoretical analysis and numerical simulation are adopted according to the blasting design scheme to establish the cumulative damage calculation model of multi-stage delay blasting with different charges.By using equivalent blasting load method and LS-DYNA complete restart technology,the blasting vibration data and the cumulative damage range of surrounding rock under multi-stage delay blasting loads are obtained.The cumulative damage effect of surrounding rock of the underground cavern is analyzed and the correlation between blasting vibrations and the cumulative damage range of surrounding rock is studied.The results show that the induced damage of surrounding rock of the underground cavern is mainly caused by blasting of the second circle holes and the surrounding hole,and the damage range of surrounding rock of the cavern vault(2.21 m)is significantly larger than that of the surrounding rock of the arch waist(2.05 m).The peak value of the blasting vibration curve is within the delay time range of cutting holes,which is not consistent with the blasting stage that causes the damage of surrounding rock.Therefore,the correlation between the peak particle vibration velocity and the damage range of the surrounding rock should be studied within the delay time which has great influence on the damage of surrounding rock.The quantitative relationship between the cumulative damage range of surrounding rock and blasting charge,blasting center distance and peak particle vibration velocity is established,and the functional relationship between the cumulative damage range of surrounding rock can be deduced from the peak particle vibration velocity at any blasting center distance.It provides a basis for controlling the blasting damage of surrounding rock and has practical significance for guiding the safety of blasting construction on site.