The Evaluation Method Of Hydraulic Support Life Based On Triangular Fuzzy Number Judgment Matrix

Hydraulic support plays a certain role in controlling mine ground pressure and ensuring the space security of the work-plane and it's also one of the most important facilities in the mine exploitation work-planes.The factors like the scurviness of mining system,high work intensity lead to high equipment failure rate,which will threaten the workers' lives,and meanwhile the high maintenance costs also become the financial burden of the enterprises.At present whether the equipment scraps or not depends on the amount of coal they conducted,service life and cycle index.However,in this way a lot of equipment which haven't reached the end of their length life scraps in advance because there are many factors that affect the equipment length,which brings great loss for the enterprises.Therefore,it's of great engineering significance to choose the appropriate indicators to evaluate the length life of hydraulic support and the effective methods to maintain and scrap the supports scientifically and reasonably.After a detail analysis of the hydraulic support's parts,this paper evaluated their length lives by FAHP(fuzzy analytical hierarchy process)and proposed the methods of judging matrix on the basis of triangular fuzzy number sequence.Choosing security indicators,reliability index,economical index and technique index as the quantitative indexes,hereby the mathematic model of comprehensive evaluation is constructed.The security indicators give the measuring method for the transformation and crack of the supporting equipment on the basis of the degree of their transformation of supporting structures and the weld failure and this paper also expounded detailedly the factors like the parts' importance of top beam and covering girder and listed their different weights.After the discussion of the factor of support's impacting on reliability,the author chose the indicators of MTBF(mean time between failures)and MTTR(mean time to repair)as its evaluation criteria.The economical index mainly is evaluated by the extended length of service,overhaul cost and the original cost ratio.The technique index chooses four main indicators of adaptation of supporting intensity to the specific pressure of seam floor,the adaptation of supporting strength to the terrane,overhaul conditions and the adaptation of pusher jack to coal seam to evaluate.Choosing fifty pieces of equipment at random as prototypes and conducting measuring analysis,whether the constructed mathematic model is reasonable is testified.The results of this research are of great significance for improving the utilization ratio of hydraulic support,reducing the loss of enterprises and guiding the update of the support.