Chapter 7: Driving BlastingContents7.1 drifting blasting7.2 shaftsinkingblasting7.3 blastingexcavationofundergroundlong-spanchamber(omitted)2016/11/9Chapter7:Driving Blasting
2016/11/9 Chapter 7: Driving Blasting 2 Contents Chapter 7: Driving Blasting 7.1 drifting blasting 7.2 shaft sinking blasting ： 7.3 blasting excavation of underground long-span chamber （omitted）
Section1:DriftingDrifting and shaft sinking engineering means excavations of drifts,shaftsand chambersmade in underground spaceto complete stoping and othermining projectsdraftsIn underground mines, drafts mean horizontal roadwaysexcavated in rock mass or ore bed and not leading to thesurface.aditsAditsmean horizontal roadways excavated inunderground space and leading to the surface.2016/11/93Chapter7:DrivingBlasting
2016/11/9 Chapter 7: Driving Blasting 3 Section 1: Drifting drafts Drifting and shaft sinking engineering means excavations of drifts, shafts and chambers made in underground space to complete stoping and other mining projects. In underground mines, drafts mean horizontal roadways excavated in rock mass or ore bed and not leading to the surface. adits Adits mean horizontal roadways excavated in underground space and leading to the surface
Workingfaceand blastholes arrangementAccording to the position and function of blastholes indrifting,they can bedivided into three classifications,which are cut holes,auxiliary holes and trimholes.Trimholesconsistofroofholes,flankholesandbottomholes.23trim holescut holesauxiliary holesAuxiliaryholes playCut holes are usedTrim holes are usedthemostimportantto generate new freerole in crushingtomakethe shapesurface and createrock.Withthehelpcrosssectionandadvantage forof newfree surfaceoutlineofroadwaysfollowing blasting.excavatedcreated by cutholes,a large crateraccordant withthedesign.canbeexcavatedbyblasting auxiliaryholes2016/11/9Chapter7:DrivingBlasting
2016/11/9 Chapter 7: Driving Blasting 4 Working face and blastholes arrangement According to the position and function of blastholes in drifting, they can be divided into three classifications, which are cut holes, auxiliary holes and trim holes. Trim holes consist of roof holes, flank holes and bottom holes. 1 cut holes Cut holes are used to generate new free surface and create advantage for following blasting. 3 trim holes Trim holes are used to make the shape, cross section and outline of roadways excavated accordant with the design. 2 auxiliary holes Auxiliary holes play the most important role in crushing rock. With the help of new free surface created by cut holes, a large crater can be excavated by blasting auxiliary holes
blastholesdblastholes:C1cut hole2?-auxiliaryhole3trim holeOVIDEO2016/11/9Chapter7:Driving Blasting
2016/11/9 Chapter 7: Driving Blasting 5 blastholes blastholes: 1—cut hole 2—auxiliary hole 3—trim hole
CutHolesOsingle line cut②pyramid cutCut holesOblique cutVcutcrack cutcylindercutParallel cutspiralcutprogressiveMixed cutspiral cut2016/11/9Chapter 7:Driving Blasting
2016/11/9 Chapter 7: Driving Blasting 6 Cut Holes Cut holes Parallel cut Mixed cut Oblique cut ③V cut ②pyramid cut ①single-line cut ② cylinder cut ① crack cut ③ spiral cut ④ progressive spiral cut