Model test study on broken rule of surrounding rock of different cross-section tunnel under blast load
WANG Hao
GUO Dongming
LI Xiaolin
ZHOU Baowei
YE Shande
YANG Jun
Abstract：Using the test method of dynamic caustic lines, the broken rule of surrounding rocks of different cross-section roadway under blast load were studied. The experimental results showed that the effect of blast load on the adjacent roadway was significantly related to the cross-section of the roadway. The broken on the di-rect-blast side of the roadway was obvious under blast load. The left side of the roadway formed a penetrating crack whose direction was generally along the horizontal one,and was from the center of borehole to the left wall of roadway,Bottom left corner of the arch-wall roadway,top left corner and bottom left corner of the rec-tangular roadway also formed three new cracks which started from the boreholes to expanding tendency. Under the action of diffracted stress wave,only the bottom right corner of the rectangular roadway on the back-blast side,formed a propagation crack. Above phenomena indicated that the unloading effect to the stress wave onthe arc section roadway is much stronger than that on the plane. A series of caustics-speckle images record the process of crack propagation,and the size of the caustics-speckle represents how much the energy accumulated in the crack tip. The process of crack propagation is the process of energy accumulation and release.
Keywords：blast loadstress wavescrackcaustics-speckle
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 27-32 )