Experimental study on the integration of drilling sealing injection of soft and broken coal

The mining roadway in the three soft thick coal seam of Zhaojiazhai Mine is an anchor net supported whole coal roadway,and the soft and broken surrounding rock sections are often encountered in the process of roadway excavation.Under the surrounding rock conditions,the key problems are common,such as poor anchor hole formation quality,serious hole collapse and low anchoring force.In order to effectively solve the support problems and improve the support effect of severely damaged local sections,a drilling sealing injection integrated grouting bolt was developed.Using a combination of theoretical analysis,laboratory experiments and field tests,the anchoring mechanism,grouting effect and anchoring performance of the drilling sealing injection integrated grouting bolt were analyzed.The research results show that the drilling sealing injection integrated grouting bolt has a better effect of grouting and sealing,which can reduce the grouting and strengthening process of soft and broken coal roadway and speed up the construction progress.During the drilling process of soft and broken surrounding rock,the vibration response characteristics of the grouting bolt are quite different.Based on this,the coal body conditions can be discriminated,which can be used for the design of grouting parameters and provides a theoretical basis for the differential grouting of roadway surrounding rock.Laboratory ultrasonic non destructive testing on grouting effect shows that the grouting bolt can effectively achieve the grouting of loose and broken coal bodies,and the slurry diffusion effect is good,indicating that the grouting bolt can achieve a good effect of grouting reinforcement for surrounding rock.The pullout test results of grouting bolt show that under soft and broken surrounding rock conditions,the anchoring force of the grouting bolt is increased by about 36.40% compared with the resin bolt,indicating that the grouting bolt can play a better anchoring effect on the surrounding rock.The above research results show that the drilling sealing injection integrated grouting bolt can significantly simplify the grouting and reinforcement process of the soft and broken coal roadway.At the same time,it can play a better anchoring effect on the surrounding rock of the soft and broken coal roadway.