Large Rock Reliefs and Their 3D Reconstructions

IOP Con e ence Se ies: Ma e ials Science and Enginee ing PAPER • OPEN ACCESS La ge Rock Relie s and Thei 3D Recons uc ions To ci e his a icle: Ondej Audy and Tomáš Ficke 2017 IOP Con . Se .: Ma e . Sci. Eng. 245 032004 View he a icle online o upda es and enhancemen s. Rela ed con en Rock Join Coe icien s De i ed om he Th ee-Dimensional Fou ie Relie s Ondej Audy and Tomáš Ficke - DEM analyses o shea beha iou o ock join s by a no el bond con ac model M J Jiang, J Liu, C Sun e al. - Op imiza ion o S e eo Ma ching in 3D Recons uc ion Based on Binocula Vision Qiyang Gai - This con en was downloaded om IP add ess 147.229.6.155 on 06/12/2018 a 12:20 1 Con en om his wo k may be used unde he e ms o heC ea i eCommonsA ibu ion 3.0 licence. Any u he dis ibu ion o his wo k mus main ain a ibu ion o he au ho (s) and he i le o he wo k, jou nal ci a ion and DOI. Published unde licence by IOP Publishing L d 1234567890 WMCAUS IOP Publishing IOP Con . Se ies: Ma e ials Science and Enginee ing 245 (2017) 032004 doi:10.1088/1757-899X/245/3/032004 La ge Rock Relie s and Thei 3D Recons uc ions Ondřej Audy 1, Tomáš Ficke 1 1 B no Uni e si y o Technology, Facul y o Ci il Enginee ing, Ve eří 95, CZ-602 00 B no, Czech Republic [email p o ec ed] Abs ac . Rock elie s a e used o assessing join ock coe icien s ha se e in geo echnical enginee ing o compu ing shea s eng h o ock join s. The h ee-dimensional elie s o small ock join s amoun ing o se e al cen ime es may be digi ally econs uc ed in labo a o ies bu la ge join s whose sizes each se e al me e s ha e o be econs uc ed in e ains and equi e a specially adap ed echnique o h ee-dimensional econs uc ion. This con ibu ion desc ibes one o he de ices capable o pe o ming digi al econs uc ions in e ains. This de ice has been de eloped in ou labo a o y on he basis o a o dable componen s. 1. In oduc ion Ba on, Choubey and Bandis [1 - 3] in oduced a model o compu ing shea s eng h  o ock join s in he ollowing o m                u n ni JCS JRC g    log (1) whe e n  is no mal e ec i e s ess, JCS ep esen s e ec i e join wall comp essi e s eng h, JRC join ock coe icien ,  basic ic ion angle (ma e ial cons an ) and u i is he inclina ion angle o ock aspe i ies ha is ela ed o la ge scale undula ion o bedding plane (second o de aspe i ies). The e m u i o second o de aspe i ies was in en ed by Bandis [3]. Soon a e he JRC concep had been published, a ious au ho s [4-6] a emp ed o ind a unc ional o m o JRC. The mos p oblema ic e m in Eq. (3) is he join ock coe icien JRC. I s alue is usually de e mined by means o compa ison o he in es iga ed ock elie s wi h he da abase elie s o known JRC alues. The i s s ep o he compu e con olled compa ison is o o m he digi al h ee- dimensional (3D) elie o he in es iga ed ock sample. The p esen con ibu ion discusses an uncon en ional p ocedu e o c ea ing 3D digi al elie s and desc ibes a de ice capable o digi izing la ge elie s in e ains. 2. Digi izing 3D p ocedu e The e a e a ious expensi e comme cial de ices o digi izing solid su aces bu we decided o de elop a new p o o ype on he basis o a o dable componen s. The de ice was cons uc ed in such a way o se e bo h in labo a o ies and e ains, i.e. o digi izing bo h he small and la ge elie s. 2 1234567890 WMCAUS IOP Publishing IOP Con . Se ies: Ma e ials Science and Enginee ing 245 (2017) 032004 doi:10.1088/1757-899X/245/3/032004 The philosophy o he de ice has been based on he sec ional echnique. This echnique econs uc s he 3D elie s by means o op ical images ha a e cap u ed subsequen ly in he e ical di ec ion abo e he solid su ace wi h a cons an s ep. S epping he came a e ically wi h a s ep ha is smalle hen he dep h o op ical ield, a con enien se o op ical sec ions may be ob ained om which he sophis ica ed so wa e c ea es he 3D elie . Figu e 1. Digi izing de ice used o labo a o y econs uc ions o 3D elie s o ock join s The si ua ion wi h common op ical de ices is a he p oblema ic. Al hough hey a e capable o p oducing op ical sec ions a p ecise heigh s, hei images con ain besides sha p poin s also blu ed ones, whose heigh s canno be iden i ied eliable. In addi ion, due o a la ge dep h o op ical ield, he e a e always se e al op ical sec ions in he acqui ed se o images ha comp ise he same poin s wi h he same sha pness and his makes hei heigh s indis inguishable. All hese d awbacks ha e o be sol ed by sophis ica ed so wa e. The e a e se e al so wa e solu ions among which he Fou ie sha pening is he mos powe ul solu ion and hus i has been implemen ed in he compu e p og am [7]. Figu e 1 shows a p o o ype o he digi izing de ice ha is con enien o labo a o y pu poses. I consis s o he pho og aphic digi al came a Canon EOS 600D mo able in he ho izon al di ec ion abo e he specimen o he ock join . The came a is connec ed wi h he compu e ha s o es he images and p ocess hem in o a inal 3D elie shown on he sc een. 3 1234567890 WMCAUS IOP Publishing IOP Con . Se ies: Ma e ials Science and Enginee ing 245 (2017) 032004 doi:10.1088/1757-899X/245/3/032004 Figu e 2. Digi izing de ice used o e ain econs uc ions o 3D elie s Howe e , he de ice adap ed o labo a o y econs uc ions can ha dly be usable in e ains. Fo e ain econs uc ions, whe e la ge specimens a e o be p ocessed, he suppo has o be ea anged. Figu e 2 p esen s he new a angemen con enien o e ain applica ions. A i s , we ha e es ed e ically si ua ed ock elie s and hus he mo emen o he came a was o ien ed ho izon ally using wo ipods as shown in igu e 2. The came a emained he same as in he labo a o y assembly and was connec ed wi h he no ebook ha s o ed he se o acqui ed images. The ho izon al mo emen o he came a is ealized manually along he me e gauge. This ho izon al s epping and aking snaps p o ide se ies o op ical sec ions whose digi al ep esen a i es se e as inpu da a o special so wa e. The da a om he came a a e ans e ed o he compu e ia USB cable. The so wa e ins alled in he compu e accomplishes he 3D econs uc ions o su ace elie s. The elie s wi h cha ac e is ic sizes abou 30cm x 20 cm we e es ed (digi al esolu ion 5184 pixels x 3456 pixels) bu in p inciple he de ice may econs uc s ill la ge o ma s eaching up o se e al me e s. 4 1234567890 WMCAUS IOP Publishing IOP Con . Se ies: Ma e ials Science and Enginee ing 245 (2017) 032004 doi:10.1088/1757-899X/245/3/032004 3. Resul s and discussions Figu e 3 shows one o he econs uc ed ock elie s. Image A) p esen s a bi d's iew on eal ock elie and image B) con ains i s econs uc ed copy (side iew) pu in he Ca esian coo dina e sys em. Figu e 3. Rock elie s: A) Pho og aphy o he na u al elie ; B) 3D copy o he elie digi ized by he sec ional me hod (a e [8]). As soon as he 3D elie s a e digi ized by he sec ional me hod, a ious heigh cha ac e is ics may be compu ed as, o example, he global pa ame e called he oo -mean-squa e (RMS) pa ame e o he elie ha is exp essed by a unc ion o wo a iables ),( yx 5 1234567890 WMCAUS IOP Publishing IOP Con . Se ies: Ma e ials Science and Enginee ing 245 (2017) 032004 doi:10.1088/1757-899X/245/3/032004    CD dxdyyx DC RMS 00 |),(| 1 (2) whe e C and D a e leng h and wid h o he elie o ma . In p ac ice, he unc ion ),( yx is ea ed disc e ely ),( ji yx and in eg a ion is eplaced by summa ion. Indica o (2) and o he pa ame e s enable a nume ical compa ison wi h he equi alen pa ame e s o he s anda d 3D elie s whose JRC coe icien s a e known and on he basis o he mos simila couples (in es iga ed elie e sus s anda d elie ) o de e mine JRC o he in es iga ed ock join . All hese ope a ions a e pe o med au oma ically on he compu e . A de ailed desc ip ion o his p ocedu e can be ound elsewhe e [8]. 4. Conclusions The sec ional me hod discussed and es ed in his con ibu ion does no equi e any special ha dwa e o c ea ing 3D elie s o ock specimens. I is capable o u ilizing common op ical sys ems like comme cial digi al pho og aphic came as. This makes he sec ional me hod much cheape compa ed o o he simila me hod. The sec ional me hod along wi h sophis ica ed so wa e is capable o p ocessing a ie y o o ma s anging om small ock specimens o la ge e ain specimens. When adding compa a i e echnique based on simila i y be ween in es iga ed ock elie s and he s anda d ones (wi h known JRC), a nume ical compu e p ocedu e is es ablished which is capable o e alua ing JRC o he in es iga ed ock join s, oo. Such a sys em may ha e a po en ial o become a usable ool in geo echnical p ac ice. Acknowledgmen Suppo o his p ojec was p o ided by he G an Agency o he Czech Republic (p ojec no. 13- 03403S). Re e ences [1] N. Ba on, Re iew o a new shea -s eng h c i e ion o ock join s. Enginee ing Geology, ol. 7, pp. 287-332, 1973. [2] N. Ba on and V. Choubey, "The shea s eng h o ock join s in heo y and p ac ice", Rock Mechanics, ol. 10, pp. 1–65, 1971. [3] S. C. Bandis, "Enginee ing p ope ies and cha ac e iza ion o ock discon inui ies", in: J.A. Hudson (ed.), Comp ehensi e Rock Enginee ing: P inciples, P ac ice and P ojec s, ol.1, Pe gamon P ess, Ox o d, 1993, pp. 155-183. [4] N. H. Mae z, J.A. F anklin and C. P. Bene , "Join oughness measu emen using shadow p o ilome y", In . J. Rock Mech. Min. Sci. & Geomech. Abs ., ol. 27, pp. 329-343, 1990. [5] N. Fa din, O. S ephansson and L. Jing, "The scale dependence o ock join su ace oughness", In . J. Rock Mech. Min. Sci. & Geomech. Abs ., ol. 38, pp. 659-669, 2001. [6] P. H. S. W. Kula ilake, P. Balasingam, P. Jinyong and R. Mo gan, "Na u al ock join oughness quan i ica ion h ough ac al echniques", Geo ech. Geol. Eng., ol. 24, pp. 1181- 1202, 2006. [7] T. Ficke and D. Ma išek, "Al e na i e me hod o assessing he oughness coe icien s o ock join s'', J. Comp. Ci . Eng., ol. 30, A icle No. 04015059, 2016. [8] T. Ficke , "Sec ional echniques o 3D imaging o mic oscopic and mac oscopic objec s", Op ik, ol. 144, pp. 289-299, 2017.