Research On Roof Weighting Mechanism Of Near Shallow Seam Longwall Face

In recent years,we have done a lot of works of typical shallow seam of YUSHENFU coalfield,and got its rock pressure rule and roof weighting mechanism.But we did little of nearshallow seam long wall face with thick base rock and two key stratas.There is no unite resultsabout its rock pressure and roof weighting mechanism.So it is important for us to grip its ruleand mechanism.It will do good to the scientific explotion of near shallow seam long wall faceof YUSHENFU coal field.With the base of the tutor's project of study abroad repatriate person of ministry ofeducation,we take 20102 near shallow seam longwall face of YUSHUWAN coal mine andnear shallow seam longwall face of HAIWAN coal mine for example.Through the actualmeasurement and analog simulation,we got the special rock pressure rule of near shallowseam longwall face.Through the analog simulation and numerical simulation,with the base ofthe key strata theory of strata contol,we got the rule of distortion and breakage of the two keystratas.At last,through the theory analysis,we got the roof weighting mechanism of the nearshallow seam longwall face.The investigation discovered that,there are a lot of near shallow seams in YUSHENFUcoal field.Its main character is that: thick basement rock,above it with two key stratas.Thenear shallow seam longwall work face still have strong rock pressure,and its rock pressuresteps are larger than typical shallow seam longwall work face.The bracket dynamic load isvery distinct during its rock pressure circles.Rock pressure steps and rock pressure strengthmanifests a large and a small with a circle change.Through anlog simulatin and numericalsimulation,the breakage distance of inferior key strata is smaller than the breakage distance ofmain key strata.The main reason of the special pressure rule is that:the non in phase breakageof both key stratas.With the basement of theory of strata control,we got the complex effect model to the near shallow seam longwall workface.The double key stratas of two near shallowseam longwall workface will both have complex effect.At last,we structured the double keystratas pressure model.we anlysed the breakage of the two key stratas and the pressure ruleand the roof weighting mechanism of near shallow longwall face.we explained the specialpressure rule properly through the modle.The investigation will offer a theory foundation tostrata control.