Innovative materials and methods for ground support, consolidation and water sealing for the mining industry

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1 Innovtive mteils nd methods fo gound suppot, consolidtion nd wte seling fo the mining industy by I.W. Nothcoft* J o u n l Synopsis UGC Intentionl, now pt of BASF the wold s lgest chemicl compny, hs developed new nge of poducts to impove sfety nd educe excvtion time in tunnel nd shft development. This ppe will discuss the dvntges of cementitious TSL in tempoy suppot s well s the full nge of injection mteils vilble fo ny gound o wte poblem. It will lso ddess the flws in pesent cementitious gouting pocedues nd povide new concepts fo wte contol to ownes nd contctos. As with fibe shotcete, UGC now hs the bility to povide complete pckge of poducts, tining nd equipment fo mico cements, colloidl silic, polyuethnes nd cylics. UGC lso hs new nge of fie esistnt ue silicte esins fo gound stbiliztion nd void filling in mines. These poducts e specificlly useful in col mines due to thei sfety fetues. Supeb technicl pefomnce combined with compehensive theoeticl nd pcticl tining cn povide the mine with quick, techniclly sound nd cost-effective solution to gound consolidtion poblems. This ppe will be divided into two pts: TSL technology fo gound suppot Injection techniques nd poducts. Thin spyed lines As n emeging technology, the functions nd popeties of TSLs e still not well undestood. It is essentil tht the uses of TSLs e povided with guidelines egding mechnicl popeties, testing fo TSLs s well s thei limittions s suppot method when used with bolts o on thei own. Uses e cutioned on the use of TSLs s mny supplies cete n expecttion of thei poduct s pefomnce, which cn be misleding. UGC Intentionl in conjunction with Pofesso Piete Kise of Mico hve developed document tht cn ssist uses of TSLs to mke n dvised choice on wht suppot TSL will povide. Types nd chcteistics of TSL Mstesel 845A Thee e mny diffeent types of TSLs on the mket. They diffe by mix type such s liquid/liquid o liquid/powde nd by type of polyme-bse. TSLs e clssified s ective o nonective, depending on thei film fomtion o cuing mechnism. Rective TSLs cue pidly by the immedite coss-linking of polymes fte mixing. Non-ective TSLs tht consist of cement/wte/polyme systems cue by loss of wte, which is theefoe eltively slow pocess. The polyme-bse gouping of TSLs is s follows: Acylic Hybid Liquid ltex whee ltex is ny known polyme (e.g. Mstesel 845A) Polyuethne Polyue Methcylte. Rective TSLs, even though the cue pidly, e sensitive to wte nd theefoe bely stick to wet sufces. Becuse of the chemicl compounds nd ection poducts, they lso cn often be pplied with only stingent sfety pecutions. On the othe hnd, non-ective TSLs even though cuing moe slowly, dhee well to wet nd dy sufces nd cn be pplied with noml sfety pecutions. UGC Intentionl s Mstesel 845A is non-ective polyme developed to combine the dvntges of ective nd non-ective * UGC Intentionl, BASF Constuction Chemicls Ltd, Switzelnd. The Southen Aficn Institute of Mining nd Metllugy, SA ISSN X/ This ppe ws fist published t the SAIMM Colloquium, The Second Undegound Opetos Confeence, Septembe P p e The Jounl of The Southen Aficn Institute of Mining nd Metllugy VOLUME 106 NON-REFEREED PAPER DECEMBER

2 Innovtive mteils nd methods fo gound suppot membnes in tht it is eltively fst cuing nd cn dhee to both wet nd dy sufces. Mstesel 845A cues by loss of wte. Thee pmetes tht chcteize the pefomnce of TSL e: Tensile stength Elongtion Adhesion. Typiclly tensile stengths of TSLs nge between 2 nd 20 MP, elongtion between 4 to ove 200%, nd dhesion between 0.4 nd 2.0 MP. Mstesel 845A hs supeio dhesion of 2 MP fte 7 dys. The mechnicl popeties of Mstesel 845A e time nd thickness dependent s shown in the following tble. Typicl chcteistics of Mstesel 845A s given in the UGC Intentionl Poduct Dt Specifiction Sheet (2006) e: Clssifiction Tensile Adhesion Elongtion stength Ltex (Polyme >1 MP fte 2 MP fte >300% fte powde) 5 hous 7 dys 5 hous >1.5 MP fte >60% fte 1 dy 1 dy >3.5 MP fte >20% fte 6 weeks 6 weeks. The ecommended thickness fo Mstesel 845A is fom 2 mm to 8 mm. Good qulity contol nd ppliction pocedues e essentil to chieve these chcteistics in consistent mnne in the field. TSLs must be envionmentlly fiendly to be ccepted fo undegound pplictions nd to ensue woke sfety. Poduct inflmmbility nd the impct of emitted fumes on ventiltion equiements often dictte poduct cceptnce. Mstesel 845A is clssified s Clss B inteio wll nd ceiling finish mteil. Thus, it cn be pplied undegound with little isk to wokes helth nd sfety. Mechnicl popeties of TSLs TSLs technology is still emeging. Hence testing pocedues fo TSL poducts e still being developed nd pesently no ecognized stndd pocedues exist fo detemining the mechnicl popeties of TSLs The lck of geed stndd pocedues fo the testing of TSLs hs esulted in the following difficulties: Vious eseches nd institutions e using diffeent testing pocedues to detemine thei mechnicl popeties, mking it difficult to impossible to compe published popeties. TSL poducts hve diffeent set times to chieve thei optiml popeties. The lck of stndd testing pocedues hs led to testing t set cue time peiods the thn t optiml poduct pefomnce times. This ppoch fvous popeties of fst-cuing poducts while undeestimting the long-tem popeties of slowe cuing poducts. Some testing pocedues do not eflect how TSLs will pefom in sevice. Some popeties (e.g. she stength) of TSLs, even though impotnt in ssessing the sufce stengthening bilities of TSLs when holding wedges, e still not vilble due to lck of pope testing pocedues. Becuse of these issues, the use is cutioned in the intepettion of models in which diffeent poduct popeties e used fo compison o fo ssessing pplicbility. Limittions of TSL models The theoy behind the functions of TSLs is still not well developed. In some counties filue modes fo shotcete s gound suppot hve been dopted to explin the functions of TSLs. Howeve, this is not completely elevnt s TSLs e diffeent mteils with diffeent functions nd diffeent wys of stbilizing ock. TSLs povide e potection nd excvtion sufce stengthening the thn stuctul suppot. They function best when cting in n integted mnne with the ock ne the excvtion wll, i.e., when they ssist the ock to emin self-suppoting. Two models e cuently being used to ppoximte the behvio of TSLs (Figue 1). These e the membne model (point loding fo punch filue o distibuted loding fo etention of boken ock) nd The bem model in which the ock nd TSL e consideed s n integl pt of the suppot system to enhnce the ock s ching o intelocking cpbility. Membne model The membne model pesupposes tht TSLs povide some stuctul suppot when in ctul fct its pimy function is to etin nd stengthen the ock between bolts nd to pevent fgments fom detching. Bem model The bem model is moe close to elity in explining the intection between the TSL nd ock to povide stbilizing effect (bsis of the TSL technology). Howeve, becuse the ctul thickness of the ock bem my neve be known the bem theoy my be consevtive whees the ctul ock bem thickness is undeestimted nd isky whee it is oveestimted. An incesing ock bem thickness inceses the lod being cpcity of the TSL-bem model. Thus the benefit of the bem model is limited to demonstting the sensitivity of the bem cpcity on the bem thickness. As indicted bove, nothe limittion of the models is tht the input pmetes e not detemined fom geed stndd test pocedues. Thus, esults of TSL models should be intepeted nd used with cution. Pimy functions of Mstesel 845A Mstesel 845A ws developed to eplce mesh s n el potection ginst the fll of eltively smll ock fgments fom both hnging-nd side-wlls. TSLs cove this function in diffeent wy fom mesh by stengthening the ock sufce nd peventing the elese of the ock fgments which, in the cse of mesh potection, would only be cught by the mesh fte the ock hs moved 836 DECEMBER 2006 VOLUME 106 NON-REFEREED PAPER The Jounl of The Southen Aficn Institute of Mining nd Metllugy

3 Innovtive mteils nd methods fo gound suppot Line Suppot t Wedge Peiphey 0.05 Unstble Wedge Dift (in section) Lod MEMBRANE Lod BEAM J o u n l Bem lod cpcity (MP) Mstesel t 5mm thickness Bem thickness=100mm Bem thickness=200mm Bem thickness=400mm P p e Spn o bolt spcing (m) Figue 1 Models illustting functions of TSLs (Espley nd Kise, 2002) Thus the dvntge of Mstesel 845A is it is n ctive suppot s opposed to mesh which is puely ective. In ddition to holding ock in plce, it lso glues smll blocks o wedges (between bolts) togethe nd in this mnne inceses the effective block size. As consequence of this ock qulity-enhncing function, the ock wll behves s if it wee of bette qulity. Mstesel 845A lso enhnces the stnd-up time of fi to poo ock msses by impoving the ching pocess though n incese of the effective block sizes. The ctul effect on stnd-up time cnnot be quntified ccutely but field evidence shows tht TSLs do slow down the fgmenttion pocesses nd impove hold-up time. Do s nd don ts when using TSLs As with most tools, TSLs function popely only when used in the ight plce, when popely instlled, nd when popely integted into n ovell suppot system. Do s Use TSLs lone: in ocks with good inte-gin bonding ocks tht e not fible in mssive to modetely (non-pesistent) jointed ock msses t low stess to etin (smll) key blocks hold smll wedges o blocks in plce when good dhesion cn be ensued to etin splled ock of hou-glssing pills o wlls when dhesion is ensued ltelly o if continuous closed membne cn be povided (ensue ounded cones nd pevent punching effects) on highly stessed ock when smll shds e being eject (spitting fce, wlls o bcks) to slow envionmentl degdtion pocesses (slking, swelling in mudstones nd cly shles) Alwys pply to clen ock sufces to chieve optiml dhesion: cefully scle nd if necessy wsh befoe ppliction. Hydo-scling hs the dded dvntge of emoving loose ock nd dit tht could cuse membne ebound. Contolled blsting pctices will enhnce the pefomnce of TSLs. Use TSLs togethe with pins o bolts s mesh eplcement: in ocks with poo inte-gin bonding when lge wedges e encounteed tht must be suppoted by bolts when elxed gound is encounteed whee deep veling is nticipted when sufce pllel splling occus to shllow depth, pticully in bcks in vey mildly stin busting conditions (with <<0.1m splls) to enhnce woke sfety in mild to modete stin busting conditions (<0.3m deep splling) togethe with mesh. Don ts Besides obviously inppopite pplictions whee the lod o defomtion exceeds the line cpcity o whee lods cnnot be tnsfeed by dhesion to ock o bolts, the following inppopite uses cn be identified. Do not use TSLs: in es whee flowing wte o othe mechnisms pevents continuous ppliction of the poduct without bolting to suppot lge wedges in stuctully contolled instbility conditions, pticully when clmping stesses e low (<2 MP) The Jounl of The Southen Aficn Institute of Mining nd Metllugy VOLUME 106 NON-REFEREED PAPER DECEMBER

4 Innovtive mteils nd methods fo gound suppot in high stess conditions whee deep seted sufce splling is nticipted lone on fible ocks such s sulphide oes (thee my be exceptions) lone on hevily blst dmged ock close to the fce if blst gsses cn penette behind the line. Also, do not use Mstesel 845A without test tils: on sufces o in conditions whee the cuing/dying pocess is pevented o significntly slowed (e.g., on fozen sufces). Appliction of Mstesel 845A In genel mny of the sme pinciples pply to Mstesel 845A s fo Fibe einfoced shotcete i.e. Sufce oughness must be smooth s possible, nd s with shotcete fee fom dust, oil nd loose ocks The equipment is n upgded Piccol Dy-Shotcete mchine which uses 90 mm 12 hole oto to delive low quntity of powde in stedy flow. A specil dust collection system is lso incopoted in the mchine The spying hose is 32 mm in dimete s is the nozzle which hs n 18 hole wte ing to ensue contolled nd even wte mixing with the powde. A dewteing device is supplied on the mchine to emove excess moistue in the compessed i; this educes mteil build up in the hoses nd the nozzle. The minimum i pessue should be 7 b t 7 m3/minute. Wte pessue should be minimum of 6 b o wte booste pump cn/should be supplied. Appliction cn be mde up to 100 metes fom the Piccol nd it is possible to chieve in excess of 90 m2/h ppliction tes. Injection in tunnels nd cvens cn be ctegoized s pe-injection nd post-injection. Both e widely used ound the wold but the tionl of the two ppoches nd thei functions in tunneling e diffeent. Pe-injection Pe-injection is the systemtic injection of gouting mteils, usully cementitious, with pessue into the ock mss hed of the tunnel excvtion fce. The tionle behind peinjection is to tet zones of impemebility nd instbility hed of the fce fom zone of eltive sfety. The dvntge of teting poo gound conditions hed of the fce is tht ock mss conditions will be in eltive stte of equilibium, i.e. wte pessues e blnced nd poo ock is confined. This will then llow the penettion of low-cost nd simple cementitious mteils nd gouts to be injected into voids, flow pths nd joints without wshout. As esult, this will then pevent wte inflows nd modify the in situ ock mss conditions pio to excvtion, hence loweing the isk of tunnel collpse nd inundtion. In ode fo contctos to undetke pe-injection s Advntges of Mstesel 845A Simple nd esy ppliction. Polyme-bsed cementious spyed powde High tensile stength Rpid stength gin poviding ely suppot h weeks Good elsticity 5 h; 6 weeks Excellent bond to ock, col nd shotcete 2.0 Mp on concete; col fils fist Does not deteiote ove time Non-flmmble Fst ppliction te:- > 100 m2/h Non toxic nd sfe to use Vey use fiendly Simple equipment fo ppliction. Figue 2 Meyco Piccol fo pplying Mstesel 845 Moden injection techniques nd mteils Mny of the mteils nd techniques discussed in this section e not eltively new o moden. Howeve, it is the systemtic nd plnned use of injection s key pt of the tunnel o shft excvtion pocess tht is of pmount impotnce. Figue 3 Hnd ppliction of Mstesel 845A 838 DECEMBER 2006 VOLUME 106 NON-REFEREED PAPER The Jounl of The Southen Aficn Institute of Mining nd Metllugy

5 Innovtive mteils nd methods fo gound suppot system, the designe must specify llowble wte outflow fom the excvtion. This is usully specified in tems of lites/min/100 m. In sub-se tunnels o tunnels with shft ccess only, the typicl limit cn be fom s little s 5 lites/min/100 m to 30 lites/min/100 m of tunnel. Pe-injection elies on systemtic pobe hole dilling in font of the excvtion fce to check fo wte inflows nd poo ock conditions tht my indicte tht poblemtic zone with high wte being cpcity nd/o ssocited instbility will ente into the tunnel fce. The infomtion obtined fom the pobe hole will then give the contcto the bility to ssess the conditions hed of the fce, nd hence mke decision s to whethe peinjection is necessy, nd with wht mteils to be used. Pobe holes cn be dilled with conventionl dilling equipment such s boome. Dill hole sizes e usully 45 o 52 mm dimete nd holes e dilled between 15 to 30 m hed of the excvtion fce. Wte ingess citei fom pobes holes e usully the min pmete tht tigges n injection cycle nd should be specified in the contct. If the wte coming fom ny one pobe hole exceeds the specified limit, then pe-injection of the fce should be stted. The benefit of pobe hole dilling is tht the point of wte ingess o the chnge in penettion te nd flush wte colou cn be identified. By dilling thee pobes it is then possible to identify the loction, dip nd dip diections of the poblemtic ock mss nd tget injection s close s possible by plcing pckes close to the identified zone. Injection pessue losses e then minimized nd the effects of the injection cn be optimized. If fom the pobe hole infomtion the decision is mde to pe-inject, full fn of injection holes e mde ound the cicumfeence of the tunnel (Figue 14). Injection holes will be dilled with the sme equipment nd to the sme depth of the pobes holes, o dilled to just coss ny identified poblem zones. Pe-injection will then be commenced into evey hole. The full cicumfeence is dilled to ensue tht gout fn ound the full peiphey of the tunnel is chieved so the wte is less likely to find n ltente pth into the tunnel. Typicl injection hole nd gout fn configutions e shown in Figue 14. The decision to stop gouting should nomlly be specified in the contct. This cn be done using two pmetes, pessue nd volume. It should be noted tht pe-injection usully mens the injection of mteils unde high pessues. Pessues of 60 b nd highe e common. Sevel fctos cn cuse these pessues: Pessue losses in the system equie high pessues to chieve modete pessue in the ock mss. Resech fom Bton highlighted tht hlf the injection pessue is lost only 1 m fom injection hole Rock msses my equie high pessues befoe the mss ccepts cementitious mteils, even though significnt quntities of wte my still be coming fom hole Pe-injection hed of the fce by definition mens tht thee e significnt confining pessues, especilly if ovebudens e high, tht cn esily withstnd gouting pessues Diltion of ock joints is of benefit to pe-injection s it ensues tht substntil gout mss will penette the ock joint impoving the seling effect of the peinjection pocess. If the injection pessue is not being chieved, then volume stop citei should be implemented sy mximum 4000 kg pe hole. This will then limit the wstge of gout by ttempting to pump to pessues. This mens tht vey stble gout should be design so tht bleed wte chnnels e not fomed in the gout when pumping is stopped. Once injection is completed, contol holes must be dilled between injection holes to veify the effects of gouting. If significnt wte ingess still occus, then the injection cycle is continued into the contol holes. If conditions e consideed OK, then excvtion cn be estted. Figue 5 demonsttes typicl decision mking pocess fo pe-injection. Fctos influencing penettion Pe-injection mteils e usully of the cementitious kind; howeve, it is impotnt the coect type of cement is used in the coect sitution nd the pe-injection gout mix is designed to give stble gout with mximum penetbility. Figue 6 shows the eltionship between gout pmete to povide gout with mximum penetbility. J o u n l P p e Typicl length: m Typicl spcing 1 2mm Figue 4 Pe-Injection is times less expensive thn post-injection The Jounl of The Southen Aficn Institute of Mining nd Metllugy VOLUME 106 NON-REFEREED PAPER DECEMBER

6 Innovtive mteils nd methods fo gound suppot Figue 5 Flow cht of injection decision citei Stbility, viscosity nd gin size e the thee pmetes contolling penetbility. The stbility of the gout mens gout with less thn 5% bleeding fte 2 hous. The viscosity is n ppent viscosity nd is mesued by Msh Cone time. The gin size is the D95 of the pticle size of the gout mix. Typiclly, micofine cements e used fo pe-injection woks. The eson is becuse the D95 gin size is less thn 20 micons vs. OPC t 60 micons. This mens significntly smlle ccks cn be injected with micofine cements thn with OPC. Also, micofine cements exhibit bleeding of less thn 5% t wte:cement tio of 1:1 s comped to OPC tht segegtes t wte:cement tios of gete thn 0.4. Theefoe, micofine cement stisfies the citei of highly stble gout (<5% bleeding), low viscosity (1:1 with Mch cone time 35 s) nd smll gin size (20 micons). The pefomnce of OPC cn be significntly impoved by using specil dispesion gent o dmixtue clled Rheobuild 2000PF. By mixing noml OPC t 1:1 wte:cement tio in colloidl high speed mixe nd dosing Rheobuild 2000PF t 1 2% bwc stbility is significntly incesed, viscosity nd theefoe penettion of the gout is significntly incesed in the ode of 200%. Rheobuild 2000PF must be used t the sme dosges when mixing Rheocem micofine cement t 1:1 wte/:cement tio fo pe-injection. The othe diffeentiting fetue of the Rheocem micofine cements is ely initil nd finl setting times of nd espectively. (1:1 w/:c 20 deg C) Comments on high wte/cement tio Cuent locl pctices stipulte tht gouting with OPC should begin t high wte/:cement tio i.e. 5:1 nd gdully decese to 2:1 depending on the tke nd pessue. This gout will still be unstble nd hve lge pticles so penettion into smll fissues will not be chieved. By ddessing the fctos bove much fste nd effective seling cn be chieved. Costs cn be minimized by stting with n OPC gout t 1:1 w/:c tio, dosed with Rheobuild 2000PF nd finishing with micofine cement. Meyco MP 320 colloidl silic Othe mteils tht e commonly used e known s minel gouts, lso temed colloidl silic. Colloidl silic hs viscosity lmost like wte (5 mps), much smlle pticle size thn cement (0.015 micons) nd gelling cn be djusted between 5 nd 150 minutes. Figue 6 Kl Gunn Holte, BASF UGC intentionl 840 DECEMBER 2006 VOLUME 106 NON-REFEREED PAPER The Jounl of The Southen Aficn Institute of Mining nd Metllugy

7 Innovtive mteils nd methods fo gound suppot J o u n l Figue 7 Meyco MP 320 Compession stength ove time P p e Figue 8 Size compison of vious injection mteils When it gels, the gel is vey soft in the beginning, but it will be stonge nd stonge ove time. The ection is not chemicl but mechnicl ection. When slt wte is dded, (the cceleto), the pticles collide to fom n impevious gel. Colloidl silic is 100% ntue poduct. It consists of silic nd NCl. Redy to use the slt concenttion is lowe thn the sewte in the Noth Se! Thee e no hzds o pesonnel isks when using it. Colloidl silic lso hs no detimentl effects on the envionment. Colloidl silic cn both be used in noml cement gout pumps, o in 2 component pumps. Colloidl silic hs excellent penettion cpbility nd it will penette fine silt nd fine hi fissues, whee micocement will not wok. Colloidl silic cn lso be used fte the injection of Rheocem 650 to tighten-up ny smll ingess of wte tht my still occu. Bentonite Bentonite hs tditionlly been used on outine bsis in combintion with cement fo gouting of soil nd ock. The eson fo doing so ws the stong tendency of stndd cement to septe when suspended in wte, enhnced by the noml use of wte:cement tio > 1.0. Bentonite cn be used to educe the bleeding in such gouts nd stndd dosge of 3 to 5% of the cement weight hs stong stbilizing effect. Bentonite is ntul cly fom volcnic shes nd the min minel ismontmoillonite. Thee e two min types: Sodium-bentonite (N-) Clcium-bentonite (C-). Mostly the sodium-bentonite is used s n dditive in cement gouts, becuse it swells to between 10 nd 25 times the oiginl dy volume when mixed in wte. The pticles esemble the shpe of plying cds nd will dsob wte on the pticle sufces, thus stbilizing the gout mix. The pticles lso sink vey slowly within the suspension becuse of thei shpe. With the tditionl cement gouting methods nd mteils, bentonite hd its plce. Howeve, in combintion with mico-cements it is nomlly not necessy nd will mostly be of disdvntge. One eson is tht typicl d95 pticle size of bentonite cly is ound 60 µm. This is two to thee times lge thn tht found in good mico-cements nd will educe the penettion chievble by odiny cement. The Jounl of The Southen Aficn Institute of Mining nd Metllugy VOLUME 106 NON-REFEREED PAPER DECEMBER

8 Innovtive mteils nd methods fo gound suppot Figue 9 Stuctue of bentonite cly fte dispesion in wte Tble I Vious injection mteils, thei ppliction nd indictive costs Injection mteil Typicl situtions/ Popeties of gout Typicl volumes Typicl cost of poblems pe job gout EUR /kg Potlnd cement Pe-injection, lge voids, Viscous suspension, suitble fo filling in Lge; > 5 tons 0.06 gound impovemento gound with high pemebility, long emovl of wte ingess open time, (pot-life), which cn be cceleted. High finl stength Mico-cement Pe-injection, injections in Suspension with low viscosity nd high Lge; > 5 tons soil o ock fo gound stbility, good penetbility. Suitble fo injection impovement o in gvel/snd nd ock with fine fissues. emovl of wte ingess Open time, (pot-life), down to 2 hous. High finl stength. Colloidl silic Pe-injection nd post injection, Extemely low viscosity fo penettion in fine Typicl volumes; injections in fine fissues in ock nd fine fissues, poes nd fine gined soils. 200 kg 10 tons gined soil gound, impovement Highly djustble gel time. nd consolidtion. Medium finl stength. Polyuethne Post-injection fo difficult situtions Rpid ecting viscous esin which cn 300 kg 10 tons 5 6 with immedite need fo gound be given foming popeties with impovement (instbilities) o wte high expnsion fctos cut-off injections Acyltes Post-injection in ock o concete stuctues, Rpid ecting low viscous esin 5 kg 100kg 3 10 o in fine gined soil whee penettion in vey with extemely good penetbility nd fine fissues o smll poes is desied highly djustble gelling time The shpe of the pticles is lso negtive fetue in this espect. Moden mico-cement gouts cn be mde with vey low viscosity nd limited o no bleeding if combined with chemicl dmixtues. Thus the ddition of bentonite is theefoe unnecessy nd negtive effect on the end esult. The finl stength of the gout is not impotnt in most cses. Howeve, with high wte heds, o when gound stbiliztion effect is impotnt, the use of bentonite t noml dosge will educe the gout stength by 50% nd moe. This cn be voided when using moden dmixtues such s Rheobuild 2000PF in mico-cement gouts, without scificing stbility o penettion. Post injection When pe-injection hs filed o not been done, it is necessy to utilize vious chemicl poducts to hndle uncontolled wte. Depending on the ntue of the poblem, UGC hs nge of poducts to sel wte o stbiles ock o col s summized in Tble II. Mining polyuethne nd ue-silicte esin injection poducts UGC hs ecently developed 3 new mining poducts due to demnd fom the col mines in Gemny nd Austli. Col mines e seeking high pefomnce, sfe chemicl gouts nd foms, which llow quick nd effective gound contol. As cn be seen fom Tble II bove, the thee new poducts e: Meyco MP 357 GS Is highly ective twocomponent polyuethne injection esin specificlly designed fo pid stbiliztion of ock nd soils. This is fst-cting flexible mteil, which cn penette ccks of 0.15 mm. It will expnd up to 3 times when not in contct with wte nd up to 8 times with wte pesent. The ection tempetues e below 140 C. 842 DECEMBER 2006 VOLUME 106 NON-REFEREED PAPER The Jounl of The Southen Aficn Institute of Mining nd Metllugy

9 Innovtive mteils nd methods fo gound suppot Tble II Poducts used to sel nd stbilize Poduct Rection time Expnsion fcto Whee to use Pump Appliction MEYCO MP 355 1K sec times To stop wte inush in 1 comp. pump Smll nd low pessue wte Acc. Adjust speed tunnels etc. Concete ccks seling s well s gound 2 10% consolidtion MEYCO MP 355 A3 djustble No wte: 0 Consolidtion nd wte stop in 2 comp pump Fo pofessionl uses Wte > 8 times cn be Tunnels etc. NB! Not in col single mix spil Smll nd vey big wte seling djusted with cc. mines, due to too high temp. s well s gound consolidtion MEYCO MP 357 GS 65 sec No wte: 0 Consolidtion in Col Mines 2 comp. pump Mining o tunnelling Wte > 8 times Also wte stopping single mix spil (like MP 355 A3) MEYCO MP 364 Flex 2 m 40 sec No expnsion with Consolidting of col nd gound. 2 comp. double All mining pplictions Fie esistnt o without wte Fo tunnels nd mines mix spil MEYCO MP sec No wte: 20 Cvity filling, wte 2 comp. double Void filling in mines FOAM Fie esistnt Wte: 20 stopping, etc. mix spil nd tunnels J o u n l P p e 140 MEYCO PUR injection systems Temp/ C MEYCO MP 357 GS Figue 10 Meyco MP 357 GS ection tempetue vs. time Meyco MP 364 Flex fie esistnt. Is twocomponent solvent fee ue-silicte injection esin specilly designed fo pid stbiliztion of col mesues, ock stt nd soils s well s epi of undewte stuctues nd concete ccks. This poduct does not expnd in o out; it lso does not bsob wte nd shows good dhesion to wet sufces. It is vey fst ecting mteil, exhibiting good stuctul stength nd flexibility nd impotntly is fie esistnt. The ection tempetue is below 90 C. Meyco MP 367 Fom Is highly ective twocomponent solvent fee non-flmmble ue-silicte fom specificlly designed fo pid cvity filling. The poduct foms without being in contct with wte, no does the wte hve ny detimentl effect on the foming fcto. Foming tkes ppoximtely seconds nd fom fcto of between times cn be chieved. The ection tempetue is below 100 C. Conclusion UGC ecognizes the needs of the custome fo one stop shop fo TSLs, injection nd gound consolidtion. We now hve full nge of top qulity poducts, excellent equipment nd ccessoies. Above ll, s with spyed concete, we now hve expetise loclly nd intentionlly to tin nd ssist customes on site. By lso developing llinces with specilized, tined ppliction contctos, we cn povide the complete pckge. We hve lso been holding pcticl injection nd TSL semins t n undegound tining fcility in Switzelnd whee clients, consultnts, nd contctos, s well s ou own enginees cn tke pt in two dy couses un by ou intenl expets. Refeences Guidelines fo Appliction of Mstesel 845A Kise nd Suoineni My PENGELLY, A.S., HOLTER, K.G., KASARANENI, R.R., nd BAHADUR, A.K. Moden Injection Techniques fo Stbilizing Difficult Gound in Rock Tunnels. Gshol, K. Pe-Excvtion Gouting in Rock Tunneling. The Jounl of The Southen Aficn Institute of Mining nd Metllugy VOLUME 106 NON-REFEREED PAPER DECEMBER

10 844 DECEMBER 2006 VOLUME 106 NON-REFEREED PAPER The Jounl of The Southen Aficn Institute of Mining nd Metllugy