Experimental Study On Corrosion Of Resin Bolt Support System In Coal Mine Roadway

Nowadays,rockbolt support has been the main support technology of coal mine roadway in China,which have made a significant contribution to China’s coal mine safety and efficient production.Coal mine underground environment is very complex.High temperature,high humidity and water spray are often seen in coal mine roadway,anchorage system servicing in those area are subjected to these harsh environment corrosion,which will be an important factor influencing anchorage structure.Literature research,theoretical analysis,laboratory experiment were used in this dissertation to study the corrosion of resin bolt support system in coal mine roadway.On the basis of the existing achievements,theoretical analysis,numerical simulation methods were used to study the function and loading condition of each part of the rockbolt support system;combined with the existed literature,the work condition of anchorage structure in coal mine were analyzed.Salt spray accelerated corrosion method was used to study unloaded/loaded rockbolts and bearing plates corrosion and mechanical characteristics,it was found that corrosion would significantly reduce the ultimate strength,elongation.The deterioration of the performance of the rockbolts were more serious,stress corrosion cracking was found,the stress corrosion was more serious under the condition of acid salt spray accelerated corrosion.Simulation method was used to study the effect of corrosion on anchorage structure,these anchorage bodies were subjected to 21 days corrosion,pull-out load was set as the evaluation index,anchorage interface changing characteristics and rockbolting failure resulted from corrosion were also studied.Based on experimental study,evaluation method of rockbolts duration based on improved grey relational grade analysis was proposed,some corrosion prevention measures of anchorage systems were given.