Analysis on Monitoring of Blasting Vibration in Semi Coal and Rock Roadway Excavation

Abstract

To study the regularity of blasting vibration of semi coal and rock roadway and its influence on the broken rock zone, the semi coal and rock roadway of Xinyi Coal Mine is taken as the test site, and the field test of blasting vibration and broken rock zone is carried out. The monitoring data analysis of blasting vibration shows that the main vibration frequency of excavation blasting in semi coal and rock roadway is 50 Hz to 250 Hz, and the main frequency of blasting vibration is higher when the detonating charge of the same section of detonator tube is large. The measured blasting vibration velocity is higher than the theoretical value, and the blasting vibration attenuation formula is fitted by using Sadov’s formula regression, then the permissible safe distance of blasting in different rock layers is calculated. The analysis of the test data of the broken rock zone shows that the range of the broken rock zone of sandstone layer surrounding rock is 1 m to 1.25 m, and the range of coal seam surrounding rock is 1.25 m to 1.5 m. The blasting vibration has little disturbance to the surrounding rock of sandstone layer, and the broken rock zone of coal seam increases by about 0.2 m. With the increase of free surface, the propagation of total explosion energy in rock mass decreases, and the disturbance to surrounding rock by blasting vibration becomes smaller. Based on the results of monitoring and analysis, the improvement measures of charging structure and supporting parameters are put forward.

Keywords

• semi coal and rock roadway
• blasting vibration
• regression fitting
• safe distance
• surrounding rock loosing circle