Numerical Tests of Rock Mechanics Report.docx

Numerical Tests of Rock Mechanics Report.docx

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NumericalTestsofRockMechanicsReport

NumericalTestsofRockMechanicsReport

（onthesubjectofRFPA）

Class

Name

StudentID

ChinaUniversityofMiningandTechnology

CollegeofMechanicalandCivilEngineering

Jan82011

NumericalTestsReport:

TheInfluenceofDifferentConfiningPressureonRockMechanicsProperties

One.Experimentcontent

UseRFPAsoftwaretoresearchthemechanicalnatureanddestruction.

Two.Experimentalpurpose

UnderstandingtheCurveofrock’sStress-Strain,strengthandfailurepattern

Three.Testingdevice

ComputerandRFPAsoftware

Four.Theprincipleofthetest

UseRFPAsoftwaretobuildasample

Thesamplesize:

100mm

50mm

Basicmesh:

100

50

Loadtypes:

planestress

Loadmethod:

oneaxisCompression

Loadconditions:

Displacementcontrolsloading

Increment:

0.002mmEachstep

Thesurroundingpressure:

0,1,2,5,10Mpa

model

Table1MechanicalPropertiesOfSpecimensElementParameterTable

Mechanicalparametersparametervalues

controlparameterparametervalues

controlparameterparametervalues

ElasticelementaverageE/Mpa

60000

Frictionangle

30°

Maximumstrainoftension

1.5

Phasevalveaverage

400

Heterogeneity

2

Maximumstrainofcompression

200

Poissonratio

0.25

ResidualCTE

0.1

Strengthcriterion

Mohr-coulombcriterion

Five.Testprocedure

a.Setparameter

Dofivegroupstestbasedontheconditionsofdifferentsurroundingrockpressure.

b.Getfiveimageseverytestrespectively.

c.GettheCurveofrock’sStress-Strainrespectively.

Six.Testdata

Whenthesurroundingpressureiszero

SteponeStepfifty-fiveStepeighty-five

SteponehundredSteponehundred

andfiveandtwenty

theCurveofrock’sStress-Strain

Whenthesurroundingpressurevalueisone

SteponeStepfifty-fiveStepeighty-five

SteponehundredSteponehundred

andfiveandtwenty

theCurveofrock’sStress-Strain

Whenthesurroundingpressurevalueistwo

SteponeStepfifty-fiveStepeighty-five

SteponehundredSteponehundred

andfiveandtwenty

theCurveofrock’sStress-Strain

Whenthesurroundingpressurevalueisfive

SteponeStepfifty-fiveStepeighty-five

SteponehundredSteponehundred

andfiveandtwenty

theCurveofrock’sStress-Strain

Whenthesurroundingpressurevalueisten

SteponeStepfifty-fiveStepeighty-five

SteponehundredSteponehundred

andfiveandtwenty

theCurveofrock’sStress-Strain

Seven.Testinganalysis

BasedontheYload（N）&loadcurvecurve,Wecangetthat,whenconfiningpressureis0Mpa，themaximumaxialloadis3928.59Nandat98th.Whenconfiningpressureis1Mpa,themaximumaxialloadis4161.73Nat110th.Whenconfiningpressureis2Mpa,Axialloadis4241.74Nat104thstep.whenconfiningpressureis5Mpa,theAxialloadis4765.19Nat120thstep；whenconfiningpressureis10Mpa,theAxialloadis4959.88Nat120th。

Contrastingtothedataoffivegroupstests,wecandrawsomeconclusions:

a.Thestressincreaseswithincreasingthestrainandafterthestressachievethemaximumvalue,itwillreducesharply.

b.Therockstrengthincreasesasthesurroundingpressureincreases.After120steps,rockbreakswhenthesurroundingpressurevalueiszeroorsmallandhardlydestructwhenthesurroundingpressurevalueishigh.

c.Thefailurepatternchangeswithincreasingthesurroundingpressure.

Whenthesurroundingpressureiszero:

spliting-crackdamage

Whenthesurroundingpressurevalueishigher:

compress-shearingdamage

Eight.Thesummary

Throughthetestweunderstandmoreaboutmechanicalnature.Inengineering,wecanincreaserock’sstrengthandfailurepatternthroughincreasingthesurroundingpressureinordertomeetpracticalneeds.

Reference

[1]ZhangHQ,ZhaoZY,TangCA,SongL.Numericalstudyofshearbehaviorofintermittentrockjointswithdifferentgeometricalparameters.IntJRockMechMinSci,2006,43:

802–816