Chapter Four Blasting Engineering GeologyMain content:4.1Thebasicnatureoftherock4.4Geologicalconditioneffectonblasting4.2Stressshockwaveinrock4.5effectof geological conditiononBlasting4.3Classificationofrock4.6Blastinggeologicalprospecting(omission)2016/11/9ChapterFour Blasting Engineering Geology
2016/11/9 Chapter Four Blasting Engineering Geology 2 Main content: Chapter Four Blasting Engineering Geology 4.1 The basic nature of the rock 4.2 Stress shock wave in rock 4.3 Classification of rock 4.4 Geological condition effect on blasting 4.5 effect of geological condition on Blasting 4.6 Blasting geological prospecting （ omission）
Section OneBasicProperties.ofRockPdensitySBulkdensityYPhysicalpropertiesporousnessrockweatheringdegreewaveimpedanceCharacteristicimpedanceofrockistheproductofvelocityoflongitudinawave (C)anddensity ofrock Pintherock32016/11/9ChapterFour Blasting Engineering Geology
2016/11/9 Chapter Four Blasting Engineering Geology 3 Section One Basic Properties of Rock wave impedance porousness Bulk density rock weathering degree density s Characteristic impedance of rock is the product of velocity of longitudinal wave（C）and density of rock in the rock. s Physical properties
MechanicalPropertiesofRocksDeformationAElasticitycharacteristicsoftherock②PlasticMechanical③BrittlenessBpropertiesThe strengthcharacteristicsof the rockC@UniaxialCompressiveStrengthElastic modulus②UniaxialtensilestrengthDShearStrengthLPoisson'sratio2016/11/9Chapter FourBlasting Engineering Geology
2016/11/9 Chapter Four Blasting Engineering Geology 4 Mechanical Properties of Rocks 岩石风化程度 A Mechanical properties B D Deformation characteristics of the rock C The strength characteristics of the rock ① Uniaxial Compressive Strength ②Uniaxial tensile strength ③Shear Strength ①Elasticity ②Plastic ③Brittleness Elastic modulus Poisson’s ratio
SectionTwoStressWaveintheRockStresswaveRock intherapidlychanging loads,both produce movementand deformation.The particlewould losethe original balanceand produce deformation and displacement,form a disturbance.Thedisturbance of aparticleisbound to causedisturbanceoftheadjacentparticles.Thisdisturbance is called the wave propagation; At the same time, the deformation will cause thestressandstrainbetweenthe particle.The propagation ofthis changein stress,strain,is calledthestressorstrainwaveDeformation produced by impactface2016/11/9Chapter Four Blasting Engineering Geology
2016/11/9 Chapter Four Blasting Engineering Geology 5 Section Two Stress Wave in the Rock Stress wave Rock in the rapidly changing loads, both produce movement and deformation. The particle would lose the original balance and produce deformation and displacement, form a disturbance. The disturbance of a particle is bound to cause disturbance of the adjacent particles. This disturbance is called the wave propagation; At the same time, the deformation will cause the stress and strain between the particle .The propagation of this change in stress, strain, is called the stress or strain wave . Deformation produced by impact face
Types of WavewaveVolumewaveSpread insidethe mediathe propagationSpread along the boundaryposition of waveSurface waveofthe mediaMediumbodysurfaceparticlemakeshorizontalvibrationLove waveperpendiculartothewavepropagationdirectionParticle movesalongRayleigh waveThevibration directiontheelliptical trajectoryofmediumparticleWiththesamedirectionlongitudinal waveof wavepropagation.Withperpendiculartotransversewavethedirection ofdisturbances propagation2016/11/96ChapterFour Blasting Engineering Geology
2016/11/9 Chapter Four Blasting Engineering Geology 6 Love wave Rayleigh wave longitudinal wave transverse wave Types of Wave the propagation position of wave Volume wave Surface wave Spread inside the media Spread along the boundary of the media The vibration direction of medium particle wave With perpendicular to the direction of disturbances propagation With the same direction of wave propagation. Particle moves along the elliptical trajectory Medium body surface particle makes horizontal vibration perpendicular to the wave propagation direction
Surface Waves and SeismicWavesRayleighwaveRayleigh waveis the surface wave of propagating along the freesurface.Wavespassby,particlesinfreesurface makereverseelliptical motion inthevertical ray plane, long axisperpendiculartothefreesurface,shortaxis parallel tothefree surface.lovewavelove waveis the surface wave of propagating along the level inBlayeredrocksurfacewave.Theparticlesmakevibrationintheformof shearing in the vertical direction of propagation of transversaldirection,novertical motion component.SeismicwaveSeismic wave is the elastic wave of particle making periodicvibration ,the sine wave of particle as a harmonic oscillator.Seismic damagemainly absolute ontheparticlevibration velocityComparedwithnatural earthquake,thefeatureofexplosionearthquake is :Source energy is small, Influence range is not big,the duration is short, high frequency,and its intensity,direction,and duration canforecastand control.2016/11/9ChapterFourBlasting Engineering Geology
2016/11/9 Chapter Four Blasting Engineering Geology 7 Surface Waves and Seismic Waves Seismic wave is the elastic wave of particle making periodic vibration ,the sine wave of particle as a harmonic oscillator. B C Rayleigh wave love wave Seismic wave Rayleigh wave is the surface wave of propagating along the free surface. Waves pass by, particles in free surface make reverse elliptical motion in the vertical ray plane, long axis perpendicular to the free surface, short axis parallel to the free surface. love wave is the surface wave of propagating along the level in layered rock surface wave. The particles make vibration in the form of shearing in the vertical direction of propagation of transversal direction, no vertical motion component. A Compared with natural earthquake， the feature of explosion earthquake is :Source energy is small, Influence range is not big, the duration is short, high frequency, and its intensity, direction, and duration can forecast and control. Seismic damage mainly absolute on the particle vibration velocity
The Media Deformation Caused by theStressWave(a)(c)(d)(b)(e)The media deformationcaused by thestress wave(a)longitudinalwave（b)Transversewave（c)lovewave;(d)Rayleighwave(e)Rayleighwaveparticlemotiondirection2016/11/9ChapterFour Blasting Engineering Geology
2016/11/9 Chapter Four Blasting Engineering Geology 8 The Media Deformation Caused by the Stress Wave The media deformation caused by the stress wave （a）longitudinal wave（b）Transverse wave（c）love wave；（d）Rayleigh wave （e）Rayleigh wave particle motion direction
Superpositionof Stress WaveSuperpositionofwavesWhen two perturbation to apoint at the same time, so that thetotal state parameterisegqualtotwo disturbance reached thisalgebra respectively,thiswascalled superposition of waves.Direct and reverse superpositionoftwo waves meetbecomethestate of a composite wave.Superpositionofwaves2016/11/9Chapter Four Blasting Engineering Geology
2016/11/9 Chapter Four Blasting Engineering Geology 9 Superposition of Stress Wave Superposition of waves When two perturbation to a point at the same time, so that the total state parameter is equal to two disturbance reached this algebra respectively , this was called superposition of waves. Superposition of waves Direct and reverse superposition of two waves meet, become the state of a composite wave
Stress Wave ReflectionandTransmission(1)(A)Normal incidenceofthestresswavefromtheinterface0, = R,0,o, =Ro,A介质1介质22p20p2P2Cp-PiCpR.R=P2Cp+PiCpP2p,+PiCpPi,plP2,Cp210,=00,=0,whenPCp=P2Cp2Does notproduceareflection of thewave,O,U;0, >0 0,>0 when P2Cp, >PCpThereflectedwaveandtransmittedwaveO,tG, =o, , = 20, when P2Cp, >> PlCpTheresultofsuperpositionofthecrossattheinterfacestressvalueistwicethat oftheincidentstresswaves,thisCUrinterfaceisthefixedendo,=-o, o,=0 when P,Cp.0when P,c<PCpLongitudinal wave vertically incidentBothtransmissioncompressionwaveand reflection stretching wave.102016/11/9ChapterFour Blasting Engineering Geology
2016/11/9 Chapter Four Blasting Engineering Geology 10 Stress Wave Reflection and Transmission (1) (A)Normal incidence of the stress wave from the interface r r i R t t i R 2 1 2 1 2 1 2 1 p p r p p c c R c c 2 2 1 2 2 1 2 p t p p c R c c 1 2 1 2 p p 0 when c c r ， t i Does not produce a reflection of the wave。 ① ② 2 1 2 1 p p 0 c c r 0 t The reflected wave and transmitted wave. ③ 2 1 2 1 p p c c 2 1 2 1 p p c c r i 2 t i ④ r i 0 t The compression wave is totally reflected tensile waves, without the transmitted wave generated. ⑤ 2 1 2 1 p p r 0 t 0 c c Both transmission compression wave and reflection stretching wave. when when when when The result of superposition of the cross at the interface stress value is twice that of the incident stress waves, this interface is the fixed end. Longitudinal wave vertically incident
Stress WaveReflectionand Transmission(2)(B)Thestresswaveoblique incidencetotheinterfaceWH40ZuαβPsLongitudinal wave oblique incidence2016/11/911ChapterFourBlasting Engineering Geology
2016/11/9 Chapter Four Blasting Engineering Geology 11 Stress Wave Reflection and Transmission (2) (B)The stress wave oblique incidence to the interface ， Longitudinal wave oblique incidence