The Material Mix Proportion of Roadside Backfill Body (RBB) Based on Spatiotemporal Law of Ground Pressure: A Case Study

The law of ground pressure behavior can accurately guide the material proportion and performance roadside backfill body (RBB) in gob-side entry retaining (GER), thereby reducing waste materials cost roadway. In this study, a similar modeling is used to verify spatiotemporal engineering case solid dense backfilling mining Xingtai Mine, China. Based on that law, theoretical requirements for bearing RBB are proposed. Finally, mix meets obtained by compression test, deformation failure characteristics with analyzed. results show maximum measured Mine 5.5 MPa, which about 40 m away from coal face; after m, force will not increase anymore. physical simulation experiment also proved behind face increases gradually tends be during process, shows certain characteristics. Through proportioning experiment, it determined optimal gangue:fly ash:cement = 10:3:1, requirement strength at any position less than position. research provide support field practice GER mining.