Control Mechanism and Support Technology of Deep Roadway Intersection with Large Cross-Section: Case Study

Conventional bolt–shotcrete support technology is usually single-layered, which does not meet the requirements of strength and stiffness for roadway support. Therefore, in this paper, new combined technology, including a multiple-layered staggered dense arrangement bolts, laying steel meshes, pouring shotcrete, strengthening long cables, full cross-section grouting, proposed. Specifically, following process proposed: first layer shotcrete (80 mm), mesh, bolt, second (50 reinforced cable, third grouting. The results show following: (1) In system superimposed coupling bearing arch, compared to cable changing parameters bolt arch can significantly vary capacity. A range spacing between 0.4 m 0.7 more conducive high performance capacity arch. (2) With increase single-layer thickness (from 50 mm 100 structure increased rapidly form power function. (3) After multi-level was adopted, ring peak zone deviatoric stress surrounding rock at intersection largely transferred shallow part, plastic reduced by 43.3~52.3% that conventional field practice model showed final roof-to-floor rib-to-rib convergences were 114 91 after 26 days, respectively. mass above depth 3 roadway’s roof sides complete, lithology dense, there no obvious crack. achieves effective control deep with large cross-section.