A STUDY ON EFFECT OF JOINT ORIENTATION ON STRENGTH AND DEFORMATION BEHAVIOUR OF JOINTED ROCK

Abstract

Rocki is differenti from otheritype of engineeringimaterialiavailable. Thatiis whyidesigningiand buildingistructureiin rockiis a difficultipractice. A detailediliterature reviewon unlikei aspects of jointedi rock massi show that the jointedirock massi behaviours effectedi by numerous factors such as jointsilocations, jointi frequency, andiorientation of jointsi and strengthsiof joints. Inithe present itudy, aniapproach has beenimade toisetup empiricalirelation toi express the jointedi rock propertiesi as a functioniof propertiesiof intactirock and jointi factor (Jf). Jointifactor is an importantiparameter in jointedirock massiand the influenceiof jointsiin theijointed rockimass is takeniinto accountiby the jointifactor in theijointed rockimass. Theregare followingisupreme significanti factors, whi ch i are responsibleifor thei strength ofi rock massi are presenceiof cracks inirock, presenceiof fault,ifissures, rocksitype, beddingi planes, Jointisurface type, andiminerals presenceiin the beddingiplanes etc. Allithese factorsialso playia significantirole in theistrength and deformationi behaviour of jointedirock mass. As in-situicomputation of jointedirock massiis very timeiconsuming and verygexpensive. An effortihas beengmade to predictithe strengthiand deformationiof rockimass throughithe testiconducted on modelimaterial testiin laboratory conditions. In rockiEngineering andidesign of rockistructure, rockimass classificationisystems haveibeen populariand are rapidlyiused. All of theseiRock classificationisystems haveitheir ownilimitations, butican be usedias approximationiwith the care, as they are very usefulitools. Different type ofijoint arrangementsihas beeniintroduced to seeithe mosticommon typesiof failureioccur in jointedirock mass. Plasteriof parisiand plasteriof paris-sand mix has been used as modelimaterial. Theispecimen haveibeen preparediby usingimodel materials, plasteriof parisiand sand-plasteriof Parisimix. In specimen, differentidegrees of anisotropy have been introduced by creating joints in specimen from zero degree to ninety degree (0◦ to 90◦). There are two type of test performed on the specimen: (i) Directishearitest, (ii) Uniaxialicompressionitest, has beeniperformed in order toiclassify theisingle jointediand doubleijointed rockimass, artificiallyimade of plasteriof paris andiplaster ofiparis-sand mix. Theseitests haveibeen performedito findiout theinumerous parametersisuch as modulusiratio, strengthiratio, uniaxialicompressive strengthietc. Thisiclassification canithereafter giveiaiprobable directioniof Rockiengineering designiconcept.