摘要
为了研究爆破掘进过程中冻结岩壁的振动及损伤特性,模型试验是一种行之有效的方法。通过相似理论设计出物理模型试验方案,对低温模型进行爆破掘进,记录关键点振动速度及频率信息,进行回归分析,确定出质点速度和频率预测公式以及两者拟合关系,利用主频率预测值反推冻结岩壁指定点的速度,并与《爆破安全规程》(GB 6722—2014)中爆破质点安全允许振速比较得出冻结岩壁损伤范围,结果表明:冻结岩壁振动规律符合萨道夫斯基公式,振动频率符合其相似准数方程,得到冻结岩壁速度和频率衰减特性;结合现场损伤测试结果认为采用规程允许振动速度可以保守地对冻结岩壁损伤进行评价,解决了定量考虑频率影响后冻结岩壁的安全性评价问题,为类似地层冻结立井爆破开挖提供科学依据。
The model test is an effective method of the study on vibration and damage characteristics of the frozen wall in the process of blasting excavation. This physical model test scheme was designed in accordance with similarity theory. The frozen model was excavated by blasting,meanwhile,recorded the vibration information of key points. The regression analysis determined the fitting formula of velocity and main frequency,as well as the relationship between the main frequency and the peak velocity. Using the predictive value of the main frequency to back calculate vibration velocity of the appointed points on the frozen wall,compared with the blasting allowable safety vibration velocity from Blasting Safety Regulation(GB 6722—2014),The results show that the vibration regularity meet the Sadov?s formula and the frequency meet the similarity criterion formula. Then the velocity and frequency attenuation characteristic of frozen wall is obtained. On the basis of field test results,it is feasible to evaluate rock damage based on the blasting allowable safety vibration velocity. The problem of the safety evaluation of the frozen wall after quantitative consideration of the main frequency effects was solved. The conclusions can provide some scientific references for frozen rock blasting in shaft for the similar strata.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2015年第S2期3732-3741,共10页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金委员会与神华集团有限责任公司联合资助项目(U1261126)
关键词
采矿工程
冻结岩壁
模型试验
爆破
频率
振动速度
损伤
mining engineering
frozen wall
model test
blasting
frequency
vibration velocity
damage
