掘进爆破对砂岩巷道围岩的影响研究

Based on the Von Mises strength criterion, radius of crushing circle and fissured circle caused by single hole blasting in blasting drilling was deducted and calculated. Through field experiment, the changes of compressive strength and tensile strength about rocks around the blast hole were researched. the results show that, Mechanical properties degradation area of surrounding rock after blasting and circle radius fracture received by theoretical analysis was basically tallies. With reference to blast hole layout of smooth blasting which commonly used in underground rock roadway, Blasting of kibble hole and auxiliary blasthole could not produce injury to the forming surrounding roadway. Blasting of surrounding holes would make injury for the rock within 15cm, and caused 9 percent decline in compressive strength and 20 percent decline in tensile strength. This study was very helpful to control of underground roadway surrounding rock and determinate the thickness of reserved safety rock .