Rock

We pro­vi­de ser­vi­ces in­clu­ding in­ve­s­ti­ga­tions, ana­ly­ses, plan­ning, re­vi­ews, mo­ni­to­ring, con­sul­tan­cy and in­spec­tions at dif­fe­rent sta­ges of the con­struc­tion pro­cess from the ini­ti­al con­cept through to the main­te­nan­ce pha­se.

We can iden­ti­fy the ge­o­lo­gi­cal and hydro­ge­o­lo­gi­cal pro­per­ti­es of rock mas­ses and de­ter­mi­ne the requi­re­ments for plan­ning and con­struc­ting ro­ads, rail­ways, brid­ges, tun­nels, rock cham­bers and buil­dings, for ex­amp­le. We al­so car­ry out eva­lu­a­tions of rock co­re samp­les, bo­reho­le vi­de­os and dif­fe­rent ty­pes of hydro­ge­o­lo­gi­cal in­ve­s­ti­ga­tions and ana­ly­ses.

On the ba­sis of the pro­per­ti­es of the rock mass and other requi­re­ments, we can de­ci­de on the de­sign of in­jec­tion me­a­su­res and rock re­in­for­ce­ment and put in pla­ce pro­duc­tion plans for tun­nel con­struc­tion.

Du­ring the buil­ding pha­se, we can pro­vi­de tun­nel sur­veys, mo­ni­to­ring and fol­low-up ac­ti­vi­ti­es and te­ch­ni­cal sup­port. The mo­ni­to­ring pro­ces­ses in­clu­de, for ex­amp­le, checks on ground­wa­ter and bolt tes­ting.

Du­ring the ope­ra­tio­nal pha­se, we can car­ry out sta­tus as­sess­ments for tun­nels and rock cuts, for ex­amp­le, and con­ti­nue mo­ni­to­ring ground­wa­ter le­vels.

Our employ­e­es who work in the fi­eld of rock in­clu­de ci­vil en­gi­ne­ers, bed­rock ge­o­lo­gists, rock en­gi­ne­ers and hydro­ge­o­lo­gists.

You can find out mo­re about so­me of the ser­vi­ces we of­fer in the are­as we spe­ci­a­li­se in.

Bol­to­me­ter tes­ting

In or­der to eva­lu­a­te the qu­a­li­ty of em­bed­ments along the length of ful­ly em­bed­ded re­in­for­cing bolts, we use a non-de­struc­ti­ve method re­fer­red to as bol­to­me­ter tes­ting. We then sum­ma­ri­se the me­a­su­re­ment re­sults in a tab­le and each bolt is au­to­ma­ti­cal­ly clas­si­fi­ed.

To inc­re­a­se the ef­fi­ci­en­cy of bol­to­me­ter me­a­su­re­ments, Ge­o­sig­ma has up­da­ted the old Bol­to­me­ter 011 in­stru­ment by ad­ding an inte­g­ral com­pu­ter and key­board. Ge­o­sig­ma has al­so been in­vol­ved in de­ve­lo­ping an im­pro­ved me­a­su­ring in­stru­ment.

Ge­o­sig­ma’s uni­que equip­ment brings a num­ber of be­ne­fits. For ex­amp­le, all the me­a­su­re­ments are sto­red in di­gi­tal form in the in­stru­ment. This me­ans that the slow, ti­me-con­su­ming pro­cess of prin­ting out the re­sults can be avo­i­ded. The IP65 ra­ting of the machi­ne me­ans that it can be used in a tun­nel en­vi­ron­ment. The me­a­su­re­ments are ma­de quick­ly and ef­fi­ci­ent­ly and the re­sults can ea­sily be re­ad on the co­lour dis­play. The bat­te­ry has an ope­ra­ting li­fe of mo­re than 12 hours. The da­ta can be trans­fer­red ea­sily to a USB me­mo­ry stick.

Ge­o­sig­ma pro­vi­des me­a­su­re­ment ser­vi­ces, a full team of staff and equip­ment. Ex­amp­les of pro­jects whe­re we ha­ve used Bol­to­me­ter tes­ting in­clu­de:

• Nor­ra Län­ken (the northern link)
• Törn­skog tun­nel
• The LKAB mi­ne in Ki­ru­na

Ge­o­sig­ma can al­so car­ry out ext­rac­tion tests on rock bolts.

Bo­reho­le vi­de­os

Bo­reho­le vi­de­os are cur­rent­ly the best method of loca­ting and docu­men­ting fractu­res and other structu­res in bo­reho­les. When com­bi­ned with an eva­lu­a­tion of rock co­re samp­les, they al­low the pro­per­ti­es of the fractu­res to be as­ses­sed ef­fec­ti­vely.

Ge­o­sig­ma uses a vi­deo method cal­led BIPS, which is a uni­que, pa­ten­ted me­ans of re­p­re­sen­ting the en­ti­re wall of the bo­reho­le (through 360º). With the help of the BIPS image, the ope­ra­tor car­ri­es out a se­mi-au­to­ma­tic sur­vey, which al­lows the structu­res to be loca­ted and ori­en­ted. The ope­ra­tor me­a­su­res the si­ze of the fractu­res and then cha­rac­te­ri­ses them.

Sin­ce 1995, Ge­o­sig­ma has log­ged mo­re than 12,000 met­res of bo­reho­le in the nu­c­le­ar was­te sector on behalf of SKB (Swe­dish Nu­c­le­ar Fu­el and Was­te Ma­na­ge­ment Com­pa­ny). In the con­struc­tion and plant buil­ding sector, we ha­ve used BIPS on a num­ber of pro­jects on behalf of the Swe­dish Trans­port Ad­mi­nist­ra­tion. We ha­ve al­so worked on pro­jects in the mi­ning and po­wer in­du­stri­es.

Flow log­ging in bo­reho­les

Flow log­ging in bo­reho­les whi­le wa­ter is be­ing pum­ped out or in­jec­ted is a ti­me-sa­ving method of loca­ting wa­ter-be­a­ring fractu­res or fractu­re zo­nes and then as­ses­sing their ab­i­li­ty to trans­port wa­ter.

Ge­o­sig­ma has built a pie­ce of equip­ment for flow log­ging which can be used in bo­reho­les of dif­fe­rent di­a­me­ters. The flow is me­a­su­red in a test pro­be using a spin­ner (a pro­pel­ler with an electro­nic unit). The equip­ment is simp­le but ro­bust. A spe­ci­al se­a­ling unit al­lows flows to be log­ged in bo­reho­les in tun­nels.

The method is ide­al for de­ter­mi­ning the loca­tion and hyd­rau­lic pro­per­ti­es of wa­ter-be­a­ring structu­res around and un­der con­struc­tions in rock. It al­so al­lows a quick and ef­fec­ti­ve sur­vey of the in­flow po­ints in a bo­reho­le to be car­ri­ed out, in or­der to iso­la­te in­di­vi­du­al hyd­rau­lic con­ductors from one another be­fo­re car­ry­ing out mo­re in-depth stu­di­es of the pres­su­re and ground­wa­ter che­mistry, for ex­amp­le.

So­me ex­amp­les of pro­jects whe­re we ha­ve used flow log­ging in bo­reho­les are as fol­lows:

• Pre­li­mi­na­ry in­ve­s­ti­ga­tions be­fo­re plan­ned mi­ning ac­ti­vi­ti­es in Pa­ja­la (Pöyry and SRK Con­sul­ting)
• Hyd­rau­lic cha­rac­te­ri­sa­tion of a lar­ge num­ber of per­cus­sion-dril­led in­ve­s­ti­ga­tion bo­reho­les (SKB (Swe­dish Nu­c­le­ar Fu­el and Was­te Ma­na­ge­ment Com­pa­ny))
• Flow log­ging in th­ree tun­nel bo­reho­les in Nor­ra Län­ken (the northern link) (Swe­dish Trans­port Ad­mi­nist­ra­tion)

In­jec­tion

The focus when con­struc­ting tun­nels and rock cham­bers is of­ten on se­a­ling the rock. In par­ticu­lar in a ci­ty en­vi­ron­ment, the rock must fre­qu­ent­ly be ma­de wa­ter­tight, which requi­res sophis­ti­ca­ted in­jec­tion pro­ces­ses. At Ge­o­sig­ma, we ha­ve 15 ye­ars’ ex­pe­ri­en­ce of re­se­arch in­to in­jec­tion methods and prac­ti­cal ap­p­li­ca­tions of the te­ch­ni­que.

Using equip­ment for de­tai­led wa­ter loss me­a­su­re­ment and our hydro­ge­o­lo­gi­cal ex­per­ti­se, we can car­ry out tho­rough eva­lu­a­tions of the hyd­rau­lic pro­per­ti­es of rock mas­ses. This pro­vi­des a re­li­ab­le ba­sis for the de­sign of the in­jec­tion me­a­su­res.

Ex­amp­les of pro­jects whe­re we ha­ve gai­ned ex­pe­ri­en­ce of this pro­cess in­clu­de:

• The Stockholm Ci­ty Li­ne (Ci­ty­ba­nan) – ad­ap­ting the de­sign of the in­jec­tion pro­cess to spe­ci­al cir­cums­tan­ces
• Tvär­ba­nan (a light rail li­ne in the Stockholm su­burbs) – de­sign and mo­ni­to­ring of in­jec­tion me­a­su­res
• SKB (Swe­dish Nu­c­le­ar Fu­el and Was­te Ma­na­ge­ment Com­pa­ny) – de­sig­ning the in­jec­tion pro­cess for a fi­nal re­po­si­to­ry (nu­c­le­ar fu­el pro­ject) and a va­ri­e­ty of ana­ly­ses
• The Both­nia Li­ne (Bot­ni­a­ba­nan) – eva­lu­a­ting and ad­ap­ting the in­jec­tion pro­cess du­ring the con­struc­tion pha­se

Blas­ting sys­tems

Ge­o­sig­ma’s employ­e­es ha­ve ex­ten­si­ve ex­pe­ri­en­ce of plan­ning, imp­le­men­ting and mo­ni­to­ring blas­ting pro­ces­ses both in Swe­den and in other countri­es.

Our ex­per­ti­se in­clu­des re­se­arch and prac­ti­cal ap­p­li­ca­tions for rock blas­ting, tun­nel driving and mi­ning.

Ex­amp­les of pro­jects we ha­ve worked on are as fol­lows:

• CLAB II – test blas­ting and blast de­sign
• Söd­ra Län­ken (the southern link) – blast de­sign for ca­re­ful, restric­ted blas­ting
• The Both­nia Li­ne (Bot­ni­a­ba­nan) – pro­duc­tion sup­port for dril­ling/blas­ting and vib­ra­tion is­sues.
• The Stockholm Ci­ty Li­ne (Ci­ty­ba­nan) – plan­ning a rock shaft for a work tun­nel

Pro­duc­tion plan­ning for tun­nel con­struc­tion

As a re­sult of its in­vol­ve­ment in a lar­ge num­ber of un­der­ground pro­jects, both in Swe­den and in other countri­es, Ge­o­sig­ma has de­ve­lo­ped ex­ten­si­ve ex­per­ti­se in pro­duc­tion plan­ning for tun­nel con­struc­tion.

We can draw up sche­du­les, op­ti­mi­se pro­duc­tion pro­ces­ses and pro­vi­de te­ch­ni­cal sup­port du­ring dif­fe­rent sta­ges of the con­struc­tion pro­cess.

Ex­amp­les of pro­jects we ha­ve worked on are as fol­lows:

• Stockholm by­pass – pro­duc­tion plan­ning du­ring the pre­pa­ra­tion of sy­s­tem docu­ments and con­struc­tion sche­du­les
• The Stockholm Ci­ty Li­ne (Ci­ty­ba­nan) – ad­ap­ting the pro­duc­tion pro­cess du­ring the plan­ning of con­struc­tion docu­ments

We can al­so pro­du­ce cost es­ti­ma­tes for tun­nel con­struc­tion.

Risk as­sess­ments for slo­pes

In the past the­re was no ea­sily usab­le, sys­te­ma­tic method for eva­lu­a­ting the sta­tus of slo­pes. Ge­o­sig­ma has worked with the Swe­dish Trans­port Ad­mi­nist­ra­tion to de­ve­lop a risk-ba­sed sy­s­tem (RRRS) for as­ses­sing the sta­bi­li­ty of slo­pes in ro­ad cut­tings. The sy­s­tem can be ad­ap­ted for use with rock cut­tings for rail­way tracks.

RRRS is a risk-ba­sed sy­s­tem used to pri­o­ri­ti­se rock cut­tings which are in need of main­te­nan­ce. The sy­s­tem is ba­sed on vi­de­o­ing the ro­ads and then docu­men­ting the rock cut­tings.

In or­der to roughly clas­si­fy the cut­tings, es­ti­ma­tes need to be ma­de for a num­ber of dif­fe­rent factors. The­se in­clu­de the amount of loo­se rock, the risk of lands­li­des, the risk of a rock sli­de co­ve­ring the ro­ad and the con­se­qu­en­ces of a lands­li­de. The­se factors are used to pro­du­ce the risk fi­gu­re.

In prac­ti­ce the rough clas­si­fi­ca­tion is car­ri­ed out by an in­spector who ta­kes me­a­su­re­ments and ma­kes es­ti­ma­tes from the ed­ge of the ro­ad. Fi­nal­ly, a de­tai­led clas­si­fi­ca­tion is ma­de. This in­vol­ves a mo­re in-depth as­sess­ment of the risks with re­gard to the costs and the be­ne­fits of ta­king ac­tion.

Du­ring 2008 and 2009, RRRS was used on around 40 ro­ads and al­most two thou­sand rock slo­pes in the coun­ty of Stockholm.

As a re­sult of its in­vol­ve­ment in a lar­ge num­ber of un­der­ground pro­jects, both in Swe­den and in other countri­es, Ge­o­sig­ma has de­ve­lo­ped ex­ten­si­ve ex­per­ti­se in pro­duc­tion plan­ning for tun­nel con­struc­tion.

We can draw up sche­du­les, op­ti­mi­se the tun­nel con­struc­tion cyc­le and pro­vi­de pro­duc­tion sup­port du­ring dif­fe­rent sta­ges of the con­struc­tion pro­cess.

Ex­amp­les of pro­jects we ha­ve worked on are as fol­lows:

• Stockholm by­pass – pro­duc­tion plan­ning du­ring the pre­pa­ra­tion of sy­s­tem docu­ments and con­struc­tion sche­du­les
• The Stockholm Ci­ty Li­ne (Ci­ty­ba­nan) – ad­ap­ting the pro­duc­tion pro­cess du­ring the plan­ning of con­struc­tion docu­ments

We can al­so pro­du­ce cost es­ti­ma­tes for tun­nel con­struc­tion.

Pum­ping tests in rock

Ge­o­sig­ma has ex­ten­si­ve, in-depth ex­pe­ri­en­ce of all ty­pes of pum­ping tests in rock. We spe­ci­a­li­se in eva­lu­a­ting and imp­le­men­ting pum­ping tests in rock. Our ex­per­ti­se is ba­sed on ye­ars of work on SKB’s (Swe­dish Nu­c­le­ar Fu­el and Was­te Ma­na­ge­ment Com­pa­ny) in­ve­s­ti­ga­tions in­to a si­te for sto­ring spent nu­c­le­ar fu­el in rock.

We imp­le­ment and in­ter­p­ret all ty­pes of pum­ping tests from simp­le pro­ces­ses in­vol­ving two or mo­re open bo­reho­les to mo­re sophis­ti­ca­ted tests in bo­reho­les with mul­tip­le pac­ker sys­tems. Pum­ping (or in­jec­tion) can ta­ke pla­ce in open bo­reho­les and in iso­la­ted sec­tions of ac­ti­ve bo­reho­les. The hyd­rau­lic con­di­tions in rock are ge­ne­ral­ly ex­t­re­mely he­te­ro­ge­ne­ous in dif­fe­rent direc­tions and at dif­fe­rent depths. Pum­ping tests can be used to es­ti­ma­te the hyd­rau­lic con­nec­ti­vi­ty in rock, iden­ti­fy hyd­rau­lic boun­da­ri­es within an area or stu­dy the hyd­rau­lic con­nec­tions between soil and rock.

The hyd­rau­lic pa­ra­me­ters are usu­al­ly in­ter­p­re­ted using mathe­ma­ti­cal mo­dels ba­sed on dif­fe­ring con­cep­tu­al as­sump­tions about the rock’s hyd­rau­lic pro­per­ti­es and do­mi­nant flow re­gi­mes.

Wa­ter loss me­a­su­re­ments

Wa­ter loss me­a­su­re­ments are per­for­med in bo­reho­les to mo­ni­tor the rock’s wa­ter-be­a­ring pro­per­ti­es. The re­sults can be used to as­sess how chang­es in the rock af­fect its sur­roun­dings, to es­ti­ma­te the amount of wa­ter flowing in­to tun­nels be­fo­re con­struc­tion work starts or to plan and mo­ni­tor grou­ting. Ge­o­sig­ma has de­ve­lo­ped a uni­que pie­ce of equip­ment for pre­li­mi­na­ry in­ve­s­ti­ga­tions in in­f­ra­structu­re pro­jects.

The Wa­ter In­jec­tion Con­trol­ler (WIC), de­sig­ned and built by Ge­o­sig­ma, gi­ves mo­re ac­cu­ra­te re­sults than ma­ny other con­ven­tio­nal in­stru­ments on the mar­ket. It has a mi­ni­mum flow of less than 2 mil­li­li­t­res per mi­nu­te, quick­ly re­aches a stab­le in­jec­tion pres­su­re and al­lows con­ti­nu­ous log­ging of pres­su­re and flow.

The me­a­su­re­ments are sto­red on se­pa­ra­te di­gi­tal me­dia. They can be used to eva­lu­a­te hyd­rau­lic con­duc­ti­vi­ty and this can be do­ne in two dif­fe­rent ways: either with the graph from the en­ti­re in­ve­s­ti­ga­tion (tran­si­ent eva­lu­a­tions) or with the fi­nal va­lue (sta­tio­na­ry eva­lu­a­tions). Tran­si­ent eva­lu­a­tions are pri­ma­rily used in are­as of low hyd­rau­lic con­duc­ti­vi­ty within the rock, whe­re sta­tio­na­ry con­di­tions can­not be ac­hi­e­ved in short tests.

Ex­amp­les of pro­jects whe­re Ge­o­sig­ma’s equip­ment has been used are:

• Stockholm Ci­ty Li­ne (Ci­ty­ba­nan)
• Stockholm by­pass

Ge­o­sig­ma has ex­ten­si­ve ex­pe­ri­en­ce of hydro­ge­o­lo­gi­cal in­ve­s­ti­ga­tions and can al­so car­ry out flow log­ging in bo­reho­les, tra­cer tes­ting, in­ter­fe­ren­ce tests and le­a­kage me­a­su­re­ments in tun­nels.

Tra­cer tests

Ge­o­sig­ma has uni­que ex­per­ti­se in car­ry­ing out tra­cer tests af­ter th­ree deca­des of wor­king in a va­ri­e­ty of are­as in­vol­ving both rock and soil. By con­ti­nu­ously de­ve­lo­ping our skills, among other things as part of our work on a fi­nal re­po­si­to­ry for spent nu­c­le­ar fu­el, we ha­ve de­ve­lo­ped a le­vel of ca­pa­bi­li­ty which can be found in ve­ry few other com­pa­ni­es throughout the world.

In­ve­s­ti­ga­tions in­vol­ving tra­cers are used to sur­vey wa­ter flows or in­ve­s­ti­ga­te the trans­port pro­per­ti­es of con­ta­mi­na­tion, for ex­amp­le. By stu­dy­ing what hap­pens to the tra­cer, it is pos­sib­le to draw con­clu­sions about the sorp­tion or na­tu­ral de­com­po­si­tion of dif­fe­rent ty­pes of che­mi­cals. The­se in­ve­s­ti­ga­tions are car­ri­ed out in both ground­wa­ter and sur­fa­ce wa­ter.

One com­mon method used in ground­wa­ter in­ve­s­ti­ga­tions is to add a tra­cer at a cer­tain po­int and then ta­ke samp­les at another po­int. The sco­pe and the ob­jec­ti­ve of the tests can va­ry from simply con­fir­ming a su­spec­ted flow rou­te to qu­an­ti­fy­ing trans­port ti­mes and flows and eva­lu­a­ting che­mi­cal pro­ces­ses along the flow rou­tes.

Another wi­dely used pro­cess is the tra­cer di­lu­tion method. This ma­kes it pos­sib­le to me­a­su­re the mag­ni­tu­de of ground­wa­ter flow in si­tu.

So­me ex­amp­les of pro­jects whe­re tra­cer tests ha­ve play­ed an im­por­tant ro­le are as fol­lows:

• Trans­port pro­ces­ses in rock to be used for a fi­nal re­po­si­to­ry for spent nu­c­le­ar fu­el. A lar­ge num­ber of tests ha­ve been car­ri­ed out on behalf of SKB (Swe­dish Nu­c­le­ar Fu­el and Was­te Ma­na­ge­ment Com­pa­ny).
• Ar­ti­fi­ci­al in­filt­ra­tion of the wa­ter sup­ply, Tam­pe­re, Fin­land. Cli­ent Ta­va­se Oy.
• Qu­an­ti­fi­ca­tion of mass trans­port in ground­wa­ter con­ta­mi­na­ted with chlo­ri­na­ted hyd­rocar­bons on the si­te of a for­mer en­gi­ne­e­ring com­pa­ny (Bah­co in En­köp­ing). Cli­ent Pe­ab.