To investigate the effect of fissure penetration on the spalling process and features of rectangular tunnel sidewalls. true triaxial compression tests were conducted on cubic sandstone specimens with varying fissure penetration degrees. Acoustic emission monitoring and video equipment were used to record the failure process of the surrounding rock in real time. The experimental result... https://www.nacrack.com/great-pick-Refurbished-Sawgrass-Virtuoso-SG500-Complete-Sublijet-Sublimation-Printer-Kit-flash-buy/