Experimental Study on the Compression Behavior of Grouted Rock with Bi-Directional Penetrating Crack

Grouting is a common method of reinforcing fractured rock mass. The mechanical property of grouted rock is a major aspect of the reinforcement effect, which depends on the geometry of the crack, the angle (β) between the load direction and the crack, and other factors. Few studies have focused on grouted rock with bi-directional crack which can reflect well the grouting reinforcement in the stratum with developed fractures. To explore the grouting effect on fractured rock mass, uniaxial compression tests were carried out on grouted rock samples with different bidirectional widths (t) and angles cracks. The results showed that: (1) when the β was 30°, the failure mode was sliding along the interface of rock and grout, when the β was 45°, the failure mode was composite failure mode, and when the β was 0°, 60°, or 90°, the failure mode was typical intact rock failure mode; (2) when the β increased from 0° to 90°, the uniaxial compressive strength (UCS) decreased and then increased again; (3) when the β was 30°, the UCS had nothing to do with the grout thickness, and when the β was not 30°, the greater the grout thickness, the greater the compressive strength and the ultimate energy storage capacity. The test results can provide reference for grouting reinforcement construction and design in the underground excavation process.