Fracture spacing behavior in layered rocks subjected to different driving forces： a numerical study based on fracture infilling process.pdf

Front．EarthSci．2014，8(4)：472_489 DOI10．1007／sl1707．014．0427一x F■一ractu‘respac-|ngb●en■avl■0rl■nI■ayered■r0Ck■SSUb■I■ecte‘1(-to‘ d■…itterent■d■n●Vl■ng．t，0rCeS：anUme¨■Cal●st一u1(0yb■ased■ontrract·ure infillingprocess LianchongLI(囡)，ShaohuaLI，Chun’anTANG SchoolofCivilEngineering，DalianUniversityofTechnology,Dalian 116024，China ◎ HigherEducationPressandSpringer-VerlagBerlinHeidelberg2014 Abstract Naturallayered rocks subjected to layer． andtheinteractionoftherfacutres，whichareimpossibleto parallelextension typicallydevelopanarrayofopening— observein feldandaredi币cultto considerwith static mode fractureswitharemarkablyregularspacing．This stressanalysisapproaches． spacingoftenscaleswithlayerthickness．anditdecreases asextensionincreasesunti1rfacturesautrationisreached． Keywords opening—mode rfactures，rfacutre spacing， Toincreasetheunderstandingofhow theseopening．mode drivingforcenumericalsimulation，heterogeneity fracutresofrnlinlayeredrocks．aseriesOf2D numerical simulations are performed to investigate the infilling processofrfacutressubjectedtodifferentdrivingofrces． 1 lntr0duCti0n Numericalresultsillustratethatanyoneoftheofllowing could be considered as a driving ofrce behind the Opening—modefracutresj(ointsorveins)areprevalent propagation ofinfillingrfacutres：thermaleffect．internal structuralfeaturesoftheEarth’scrustoccur in many fluidpressure，directextension1oading，orpurecompres— differentrocktypesand tectonicenvironments，andare sive loading．Fracutre spacing initially decreaseswith offenperiodicallydistributedwithspacinglinearlyrelated loadingprocessandatacertainratioofrfacutrespacingto to the thicknessofthe rfactured layer．Figure 1 and layerthickness．nonewfracturesnucleate(sautrated)．Both Figure2 show htenautralffactured behavior atboth an increase in theopening ofthe infilled fracturesand surfaceanddepthint