Mechanical models and support technologies for retaining gob-side entry

Abstract

Aiming at gob-side entry retaining for three typical roof conditions (hard roof, medium stable roof and limestone roof), theoretical analysis, numerical simulation, laboratory test and field test were carried out. Different support mechanical models were built, and various roadside support technologies were presented. Results show that: for retaining gob-side entry of hard roof, flexible-stiff support mechanical model was built, quantitative calculation method of thickness, strength and size of flexible and stiff filling body were deduced, and filling materials of flexible and stiff support body were developed. Strain hardening characteristic of anchored gangue body was revealed, and roadside filling support technology with transversely anchored gangue body was presented for retaining gob-side entry of medium stable roof. Based on the slow subsidence motion characteristic of limestone roof, cutting off roof of roadside support with hydraulic props, anchor cables and auxiliary blasting was proposed, and showed good cutting