Abstract: The response of long bolts in weathered and fractured granite under blasting was experimentally studied. The opening supported with long bolt and shotcret was chosen for the design, which was examined by monitoring stress states and particle vibrations round the opening during blasting. Borehole TV, sonic wave method and macro investigation were also used to determine fracture features post blasting. Neither falling rock nor bulging on bottom were found. The long bolt strengthened opening has proved to have good support effects and excellent response against blasting, compared with neighbouring unlined or short bolting opening.