轻轨隧道循环掘进爆破地震效应研究
王辉,丁雄
(湖南科技大学 土木工程学院,湘潭 411201)
摘要:以重庆轨道交通环线冉家坝浅埋轻轨隧道工程为背景,进行循环掘进的地表爆破震动效应试验。通过测量隧道地表不同位置处引起的振动速度波形,研究地表震动特性及爆破地震波的传播和衰减规律。试验研究分析发现,掌子面前后的地表振动速度存在显著地差异,已开挖成形隧道改变了岩体的整体结构,爆破振速存在放大效应,且放大后的爆破振速随距离的增大而减小,用常规的萨道夫公式预测成形隧道地表的振动速度误差较大,而通过编写matlab函数进行数据统计、多元线性回归分析求出广义的爆破震动速度计算公式,预测成形隧道地表振动速度误差较小。所以广义的爆破震动速度公式预测成形隧道地表振动速度值得推广。
关键词:爆破震动;衰减规律;回归分析
Experimental Study of Blasting Seismic Effect Resulting from Circular Driving in Light Rail Tunnel
WANG Hui,DING Xiong
(College of Civil Engineering,Hunan University of Science and Technology,Xiangtan 411201)
Abstrat: Taking the project of Ranjiaba shallow light rail tunnel of chongqing rail transit circle as the background, the field experiments of blasting vibration effects of the ground in circular driving have been done. Based on the measurement of the waveforms of the vibration velocity in different distances on the ground, the vibration characterist of the ground and the propagation and attenuation laws of lasting seismic wave are studied. The research tests and analysis found that the ground vibration velocity of in the front of and behind the tunnel face existing significant differences, the rock mass of the entire structure have been changed for the tunnel has been forming result from excavating, Blasting vibration velocity has being magnifying effects and the blasting vibration velocity has been magnified decreases with the increase of distance. Predicting the forming tunnel of the ground blasting vibration velocity with sadov’s formula has a larger error, And by writing matlab function for data statistics and multivariate linear regression analysis to find the general formula of blasting vibration velocity, predicting the forming tunnel of the groun vibration velocity with a small error. So the generalized tunnel blasting vibration velocity formula to predict the forming tunnel of the ground vibration velocity is worth promoting.
Key Words:Blasting vibration;Attenuation law;Regression analysis