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Working report 97-56e

Application of raiseboring for excavating horizontal tunnels

with Rhino machines

Arne Lislerud

Tamrock Corporation

Pauli Vainionpaa

TAB-Raise Borers Ltd

December 1997

Mikonkatu 15 A, FIN-00100 HELSINKI , FINLAND

Te l. +358-9-2280 30

Fa x +358-9 - 2280 3719

Working report 97-56e

Application of raiseboring for excavating horizontal tunnels

with Rhino machines

Arne Lislerud

Tamrock Corporation

Pauli Vainionpaa

TRB-Raise Borers Ltd

December 1997

~£mm©~~

~- December 9, 1997 RAISE BORERS

Client:

Contact persons:

Authors:

Posiva Oy Mikonkatu 15 A 00100 HELSINKI

Jukka-Pekka Salo, Posiva Oy \!) Jorma Autio, Saanio & Riekkola Oy Arne Lislerud, Tamrock Corp. Pauli Vainionpaa, TRB-Raise Borers Oy

APPLICATION OF RAISEBORING FOR EXCAVATING HORIZONTAL TUNNELS

WITH RHINO MACHINES

~~ /./s/.7}, Arne Lislerud

9~ Pauli Vainonpaa

Working reports contain information on work in progress

or pending completion .

The conclusions and viewpoints presented in the report

are those of author(s} and do not necessarily coincide

with those of Posiva.

APPLICATION OF RAISEBORING FOR EXCAVATING HORIZONTAL TUNNELS WITH RHINO MACHINES

ABSTRACT

One part of the development of the basic KBS-3 concept and other alternative disposal concepts for spent nuclear fuel has been the development; evaluation of the suitability of different excavation techniques such as raiseboring. Raiseboring has been used to excavate shafts since the 1970's and has proved to be an effective mechanical excavation method to excavate holes with circular shape in hard rock with little excavation disturbance to the surrounding rock. Raiseboring has also been used to excavate horizontal tunnels in hard rock. Similar tunnels but of different size and different underground environment have been proposed for use in the KBS-3 concept instead of the Drill and Blast or the tunnel boring (TBM) to excavate the deposition tunnels and in the MLH concept to excavate the long horizontal deposition holes.

This report presents the principles of horizontal raiseboring, case studies, a proposed method for boring horizontal deposition tunnels in KBS-3 concept and deposition holes in MLH concepts. The equipment is designed by TRB - Raise Borers Ltd. Finally performance prognosis for the proposed method based on the described equipment is given for the different main rock types at the three different candidate sites selected for more detailed site investigations in 1992.

Keywords: raiseboring, horizontal raiseboring, mechanical excavation

VAAKATUNNELEIDEN LOUHINTA RHINO NOUSUPORAUSKONEILLA

TIIVISTELMA

KBS-3 tyyppisen loppusijoitusratkaisun ja vaihtoehtoisten ratkaisujen kehittfunisen ohessa on arvioitu ja kehitetty yksitHiisten tekniikoiden, kuten esimerkiksi nousuporauksen soveltuvuutta loppusijoitustilojen louhintaan. Nousuporausta on kaytetty menestyksekkaasti 70-luvun alusta lahtien kuilujen louhintaan ja se on osoittautunut tehokkaaksi menetelmaksi tehda pyorea kuilu kovaan kallioon siten etta louhinnan aiheuttama hairio kiveen on vahainen. Nousuporaustekniikkaa on kaytetty myos vaakatunnelien tekoon kovaan kiveen. Loppusijoitustekniikan kehittamisen yhteydessa on esitetty KBS-3 tyyppisten loppusijoitustunnelien louhimista nousuporaustekniikkaa kayttaen perinteisen poraamalla ja rajayttamalla tapahtuvan louhinnan tai tunneliporauksen sijasta. Nousuporaustekniikkaa on esitetty myos kaytettavaksi MLH loppusijoitusratkaisun pitkien vaakatasossa olevien loppusijoitusreikien louhintatekniikaksi.

Tassa raportissa kuvataan vaakasuuntaan tapahtuvan nousuporauksen periaate, casetutkielmia, ehdotus porausmenetelmaksi KBS-3 tyyppisten loppusijoitustunnelien ja MLH tyyppisten sijoitusreikien poraamiseksi seka kuvataan suunnitelma edella mainittuihin sopivasta laitteistosta, joka perustuu TRB - Raise Borers Ltd:n laitteistoihin. Lisaksi esitetaan arviot edella mainittujen laitteiden tehokkuudesta kolmen 1992 jatkotutkimuksiin valitun sijoitusaluevaihtoehtoalueen paaki vilajeissa.

A vainsanat: nousuporaus, vaakaporaus, mekaaninen louhinta

TABLE OF CONTENTS

ABSTRACT

TIIVISTELMA

TABLE OF CONTENTS

1 INTRODUCTION 1

2 INTRODUCTION TO RAISEBORING 4

2.1 THE MAIN STEPS IN RAISEBORING OPERATION 4

3 CASE STUDIES OF HORIZONTAL RAISEBORING 7

3.1 HAUKVIKA HYDRO POWER PROJECT, NORWAY 7

3.2 MYLL YPURO TEST MINE 11

3.3 PERSEVERANCE MINE, LEINSTER, AUSTRALIA 13

3.4 DIRECTIONAL DRILLING AND RAISEBORING THE BJERUM TUNNEL 15

3.5 STATISTICS FROM THE HORIZONTAL SHAFT AT ROMSAS, OSLO 17

4 DESCRIPTION OF THE METHOD AND TAB-EQUIPMENT FOR BORING HORIZONTAL DEPOSITION HOLES (0 1.68 m) AND DEPOSITION TUNNELS (0 4.0 m) 20

5 MACHINES- HORIZONTAL RAISEBORING 22

6 PERFORMANCE PROGNOSIS 35

7 SUMMARY AND CONCLUSIONS 38

8 REFERENCES 39

1

1 INTRODUCTION

Plans for the final disposal of spent nuclear fuel in Finnish crystalline bedrock were comprehensively reported in 1992. The technical plans are presented in report YJT -92-31E (TVO 1992a); the results of preliminary investigations at five candidate sites are contained in report YJT -92-32E (TVO 1992b). In parallel with the development and assessment of the basic concept, the suitability of alternative concepts for the disposal of spent fuel in the Finnish bedrock were studied in 1989 - 1991. A more comprehensive evaluation of alternative canister and repository designs was carried out in SKB's PASS project between 1991 and 1992 (SKB 1992). Since 1993, the focus of research and development on encapsulation and disposal technologies has been on further development of the KBS-3 repository designs, see Figure 1-1. The interim reports on encapsulation, disposal technologies and repository designs for the basic KBS-3 concept are presented in (Posiva 1996) and (Riekkola & Salo 1996).

Figure 1-1. KBS-3 type Basic Concept for the final repository for spent fuel (TVO 1992a).

2

Bentonite

Canister

Figure 1-2. Cross-section of a KBS-3 type deposition tunnel. Canisters are emplaced in holes excavated in the tunnel floor and surrounded by bentonite clay.

In parallel with the development work on the KBS-3 basic concept, development and assessment of alternative disposal concepts and specific techniques has continued. Three alternatives to the basic KBS-3 design were assessed (Autio et al. 1996): KBS-3-2C with two canisters in a deposition hole, Short Horizontal Holes (SHH) in the side walls of the tunnels, and the Medium Long Holes (MLH) concept, in which some 25 canisters are emplaced in a single, horizontal, approximately 200 metres long deposition hole bored between the central and side tunnels.

One part of the development of the basic KBS-3 concept and other alternative disposal concepts has been the development and evaluation of the suitability of different excavation techniques such as raiseboring for the excavation of the repository. Raiseboring has been used since the 1970's to excavate shafts and has proved to be an effective mechanical excavation method to excavate holes with circular shape in hard rock with little excavation disturbance to the surrounding rock. A new technique based on raiseboring type rotary crushing and removal of cuttings by vacuum flushing was developed and demonstrated (Autio & Kirkkomaki 1996) for the boring of deposition holes. Raiseboring is also a potential technique for the excavation of shafts other than the investigation shaft down to the repository. Raise boring has also been used to excavate horizontal tunnels in hard rock. Similar tunnels but of different size and different underground environment have been proposed for use in the KBS-3 concept instead of Drill and Blast or tunnel boring (TBM) to excavate the deposition tunnels, see Figure 1-2, and in the MLH concept, see Figure 1-3, to excavate the long horizontal deposition holes. The Finnish design variation for the VLHconcept (Autio 1992) was also based on the use raiseboring.

3

Canister Transfer Shaft

Side Canister

Central Tunnel

/ Deposition Tunnel ' I

Central funnel

Figure 1-3. Lay-out and cross-section of the MLH concept.

The limitations of raiseboring have been associated mainly with cutterhead diameter limitations with respect to efficiency, straightness and case of cuttings removal in horizontal boring. This report represents the principles of raiseboring in Chapter 2 and case studies of horizontal raiseboring in Chapter 3. A poroposal for a method for boring horizontal deposition tunnels in KBS-3 concept and deposition holes in MLH concept is given in Chapter 4. The equipment design by TRB- Raise Borers Ltd is given in Chapter 5. Finally the performance prognosis for the proposed method based on the described equipment in Chapter 5 is given in Chapter 6 for the different main rock types at the three different candidate sites selected for more detailed site investigations in 1992.

4

2 INTRODUCTION TO RAISEBORING

Raiseboring is a well established full face excavating method. In full face methods the whole cross section of the hole is bored to the final diameter with no use of explosives.

The Raiseboring Method consists of drilling a pilot hole first, followed by reaming of the pilot hole to the final diameter. The pilot hole diameter is somewhat larger than the drill rods; and the direction of drilling is generally vertically down or inclined. The reaming to final diameter is generally made in the opposite direction (back reaming).

2.1 THE MAIN STEPS IN RAISEBORING OPERATION

Site preparation:

- A flat concrete foundation is made for the raiseboring machine. - A small water reservoir (dam) is prepared for the flushing water. - The machine base plate is anchored to the concrete with rock bolts.

Transportation and machine assembly:

- Transportation of power units and machine to the base plate. - Raiseboring machine attached to the base plate. - Machine alingned for pilot hole drilling. - Storage site for drill rods prepared; drill rods and other drilling

accessories transported to the drilling site.

Figure 2-1. Typical arrangement for pilot drilling.

5

Pilot Hole Drilling:

- The pilot bit is connected to the starter sub (see Chapter 3 for details) with a check-valve and the sub is connected to the first stabilizer.

- Connect flushing hoses.

In pilot hole drilling, flushing medium is used to bring the cuttings up from the hole. The alternatives for flushing are the use of compressed air, water, a mixture of air and water, or mud.

In normal conditions, water flushing gives the best boring efficiency. In addition, no air borne dust is produced when water flushing is used. The simplest way to organize water flushing is to have a closed circuit from a dam built close to the machine. Water is pumped from the dam, through the machine and the drill rods to the pilot bit, and the outgoing water and the cuttings are lead (pumped) back to the the dam; where the debris can settle and the clean water is reused.

Pilot Hole Break-Through - Reaming Preparation:

- When the pilot bit breaks through, the pilot bit and some stabilizers from the drill string are removed.

- The rock face at the break -through point should be as close to 90 degrees as possible. In most cases the rock face has to be trimmed straight and made perpendicular to the pilot hole.

- The reamer head is attached to the drill string and the thread connection between the stem and the stabilizer is made up with the correct torque.

Reaming:

Reaming is started with a low rotation speed and low reamer force until the collaring is completed. When the machine is rotating the cutterhead and pulling it against the face; the rock is broken by tungsten carbide inserts on freely rotating cutters mounted on the reamer head. Most of the premature cutter and stem failures are caused by poor collaring, i.e. too high feed force and rotation speed have been utilized in this stage.

When the reamer head is boring with the whole diameter, net advance rates can be brought to normal levels, i.e. 0.5 to 2.0 meters per hour depending on diameter and rock mass conditions.

6

Figure 2-2. Typical arrangement for reaming.

Finishing the Hole:

- With modern machines, the reaming is carried out all the way to the machine. If the head has to be lowered, it may mean an additional week's work.

- The reamer head is fastened with a chain to a beam placed above the raise and the thread connection of the stem is opened.

- Machine and base plate are dismounted and transported to the next hole. - The possible uncut edge (for inclined holes) is sliced away and the

reamer head can be lifted away from the top of the raise.

7

3 CASE STUDIES OF HORIZONTAL RAISEBORING

Horizontal raiseboringis boring with zero or a small angle to the horizontal plane. For standard raiseboring, the pilot hole is flushed with water to bring the cuttings out, and during reaming gravity takes care of the cuttings. In horizontal raiseboring, special attention has to be taken for cuttings removal. In pilot drilling the water flow has to be adequate to prevent the cuttings from settling along the bottom of the hole. During reaming the cut face must be cleaned, the cuttings brought to the other side of the reamer head, and finally remove the cuttings from the tunnel. The details of these arrangements and other specialties connected to horizontal raiseboringwill be discussed in more detail later on this chapter.

3.1 HAUKVIKA HYDRO POWER PROJECT, NORWAY

Two unlined near-horizontal tunnels for a combined small hydro power plant and fresh water supply for local fish farmers at Vinje0ra were raisebored by Astrup H0yer A/S from October 1986 to May 1987.

Location Client Contractor Generator Annual Production

Haukvika, Vinje0ra, S0r Tr0ndelag Haukvik Kraft A/S Astrup H0yer A/S 2.3MW 10GWh

1:20

Figure 3-1. The power plant tunnels are shown on the sketch above.

8

Table 3-1. Tunnel data and operational data at Haukvika.

Tunnel Data

Length Diameter Inclination Construction Time

Operational Data

Machine Rods Pilot Bits

Reamer for Tunnel I Cutter Dressing for Tunnel I

Reamer for Tunnel II Cutter Dressing for Tunnel II

Tunnel I

685m 1.06m

- 60 4 months

Rhino 1000E 5'1 10" Reed 11"

Tunnel 11

550m 1.35 m - 10.5°

3.5 months

Sandvik CRH3, (01.06 m Sandvik 2@ CMR41 and 2 @ CMR51 cutters

Sandvik CRH4, 01.35 m Sandvik 3 @ CMR41 and 3 @ CMR51 cutters

Table 3-2. Proporties of medium grained granitic gneiss at Haukvika.

Rock Type

Brittleness Value, S2n Density Sievers 1-Value Abrasion Value Carbide, A V Abrassion Value Steel, A VS Cutter Life Index, CL! Drilling Rate Index, DRI Vickers Hardness Rock, VHNR

Mineral Content Percentage (XRD):

Quartz Plagioclase Orthoclase Amphibole Calcite Mica Chlorite

46 2.62 glcm3

4.1 20 mg/5min 14 mglmin

8.6 42

821

28% 31% 37% 0.5% 1.0% 1.5% 1.0%

9

The pilot hole for the first tunnel was drilled from mid October till the beginning of December. The pilot hole drilling was delayed due to two wrecked pilot bits and remaining metal fragments from the bits on the holebottom. The last wreckage occurred only 15 m from break-through. During the 7 remaining work days before the Christmas Holidays, 145 meters of tunnel were reamed. The next tunnel section of 315 m was reamed in 10 days after which the cutters were changed from within the tunnel. The remaining 225 m were reamed in 5 days.

The contractors' experience of reaming these two near-horizontal tunnels was that the wear and tear of the drilling equipment was higher than for traditional raise boring. Wear on peripheral cutters was about twice the normal rate. Stabilizer wear was also higher than usual. The removal of cuttings was done by water flushing. Desired flush flow rates for this kind of work is approx. 1000 - 1500 1/min.

Pilot hole deviation was monitored in stages using a gyro for the first 200 m. After this, a compressed air system was used for measuring bit altitude. Bit feed force and rotary speed settings for the following pilot hole section were determined by the bit altitude deviation. The vertical deviation of the pilot hole was crucial (water levels), and on break-through totaled 0.60 m for Tunnel I. The horizontal deviation was pronounced; but of no significance to the power plant design. It totaled 25 m.

Figure 3-2. Haukvika job site overwiev.

10

Pilot Hole Drilling - Tunnel 11

4.5

4.0 -..c 3.5 ......

E -a. 3.0 0

a: s::::: 2.5 0

:;:::; cu loo.

2.0 -Cl,) s::::: Cl,) a. - 1.5 0 Cl,) - 1.0 cu a:

0.5

0.0 0 (X) I"-- lO C\1 0 (X) I"-- <0 ..q- C') .,- 0 0) I"-- <0 lO C') C\1 .,-

C\1 lO (X) .,- ..q- <0 0) C\1 lO (X) .,- ..q- <0 0) C\1 lO CO .,- ..q-.,- .,- .,- .,- C\1 C\1 C\1 C') C') C') C') ..q- ..q- ..q- lO lO

Depth from Machine (m)

Reaming - Tunnel 11

4.5

4.0

-..c 3.5 ......

E -a. 3.0 0

a: s::::: 2.5 0

:;:::; cu loo.

2.0 (i) s::::: Cl,) a. 1.5 -0 Cl,) - 1.0 cu a:

0.5

0.0 0 CO I"-- <0 lO ..q- C\1 .,- 0) I"-- <0 lO C') C\1 .,- CO <0 ..q- C\1 C') lO CO .,- ..q- I"-- 0 C') lO CO .,- ..q- I"-- 0 C') lO (X) .,- ..q-

.,- .,- .,- C\1 C\1 C\1 C\1 C') C') C') ..q- ..q- ..q- ..q- lO lO

Depth from Break-Through (m)

Figure 3-3. The overall performance of the pilot hole drilling and reaming of Tunnel//.

11

Table 3-3. Net penetration rates for the reaming of Tunnel I and at Rod #310.

Force on Force on ROP Net Reamer Reamer Cutter Reamer Row Penetration RPM Torque Coeff.

(kN) (kN/row) (m/h) (mm/rev) (kNm) k

460.0 20.19 1.84 1.80 17.0 6.0 0.0493 515.0 23.24 1.52 2.54 10.0 6.25 0.0446 660.0 31.30 0.91 4.11 3.7 10.0 0.0530 480.0 21.30 2.22 2.06 18.0 7.0 0.0545

3.2 MYLL YPURO TEST MINE

After manufacturing the first Rhino 1000 E; this machine was tested by making a 62 meter long horizontal tunnel of diameter 2134 mm. The tunnel was bored in Tamrock Test Mine in 1973. For this prototype machine Tamrock also manufactured the first Tamrock 10" drill string. The reamer head was manufactured by Tamrock for Smith cutters. The head was specially designed for horizontal boring. There were special wings welded on the reamer to lead the cuttings behind the head. Four cutters were placed as rollers supporting the head against the tunnel wall. A special block was attached behind the reamer for the scraper system used to bring the cuttings out of the tunnel. The machine with the original drill string is still in operation.

Table 3-4. Test results.

Machine: Rhino 1000 E Reamer: Modified Tamrock/Smith 7ft, 16 + 4 (stab) cutters,

7 button rows/cutter Reaming 16 RPM

Force on Force on Reamer Cutter Cutter ROP Specific Reamer Row Torque Coeff. Constant Energy

(kN) (kN/row) (kNm) k (m/h) (kWh/m 3)

785 7.01 41.20 0.087 0.28 69 981 8.76 51.01 0.086 0.46 52

1177 10.51 58.86 0.083 0.1014 0.64 43 1373 12.26 64.75 0.078 0.0827 0.85 36 1570 14.02 76.52 0.081 0.0787 1.02 35 1668 14.89 78.48 0.078 0.0718 1.13 32

12

Table 3-5. Drilling data from the horizontal hole in the Tamrock Test Mine. (Pilot drilling)

1. Geology - Formation Unconfined Compressive Strength Relation of Bedding Dip

Granodiorite 150 MPa

no bedding, some near vertical joints to Pilot Hole

2. Pilot Hole - Inclination from Horizontal Diameter Length

3. Drill- Make and Model Average Thrust Used Average Torque Used Average RPM

Circulating medium - air

4. In-Hole Tools Bit-

water other

Make and Type Diameter Bit L~fe

0.4° downwards 12-114 " 62m

Rhino 1000 E 25- 30 tons

40RPM

120 - 250 1/min

Dresser 12-114 "

Stabilizers - Make and Type Tamrock, integr. six-rib Diameter 12-" Number and Location four, 32 m, 51 m, 61-62 m

Drill Rods- Make and Type Diameter Wall Thickness

5. Rate of Penetration (A vg)

6. Hole Survey - Type

Frequency of Survey

7. Techniques Used to Control Deviation

8. Hole Deviation

Tamrock 6ft 10"

1-1;4 "

2.23 mJh

manual observation and with teodolite

Stabilizers and thrust

% up and right

13

Figure 3-4. Principle of reaming and the cutterhead used at Tamrock test mine.

3.3 PERSEVERANCE MINE, LEINSTER, AUSTRALIA

In 1991 - 1992 three horizontal holes were bored at Perseverance Mine, Leinster, Australia. The diameter of the holes were about 4 meters and the length of each was about 80 meters. The rock types at Perseverance Mine are minely schists.

Table 3-6. Mineral Content Precentage (Thin Section).

Graphite Chlorite Serpentine

37% 34% 29%

Figure 3-5. Horizontal b . onng.

_____ I r----K./0 4 . . 5M

14

p,· lgure 3-6. Reamer head arrangement.

0 4.0M

15

Table 3-7. Horizontal boring.

Case: Location:

Contractor :

Tunnel Dia: Tunnel Length: Pilot Hole Dia : Drill Rod Dia : Rock Compr.Strength: Reamer Type : Machine Type :

UG-DRIVES FOR LONGHOLE DRILLING LEINSTER NICKEL MINE, WESTERN AUSTRALIA AUSTRALIAN RAISE DRILLING

4-4.5 m 35- 100 m 13 3/4" 12 7/8" 50- 150 MPa SANDVIK CRH13 SP ROBBINS 85R

3.4 DIRECTIONAL DRILLING AND RAISEBORING THE BlERUM TUNNEL

Directional drilling was applied in 1991 at Brerum near Oslo in completing a 1.8 m diameter and 295 m long raise that was bored through hard rock in Norway.

Directional diamond drilling

Directional drilling in aluvium and softer sedimentary rocks is a widely established technique for laying pipes and cables beneath obstructions.

The technique has been used for power and communication cabling, sewerage and water pipelines. A growing requirement is the diversion of river courses in roadworks and hydro schemes.

Directional diamond drilling along a proposed line can be carried out using a steerable corebarrel, the Vie Drill Head from Devico A/S, Norway. For the critical positional surveying during this phase, a Maxibor in-hole surveying device from Reflex Instrument AB is used. This non-magnetic device measures the small changes in direction over each 3 m length of hole. Once completed, the directional pilot holes are then reamed up in two or three phases to the final diameter using a horizontal raiseboring system.

This technique was used in the completion of a 1.8 m diameter tunnel beneath Brerum, a residental area near Oslo, Norway. The work was carried out by Drill con AB. The tunnel was designed to carry sewerage, storm water and fresh water in three separate pipelines. The directional pilot hole was drilled using an Onram 1000 core drill, manufactured by Hagby Bruk AB. Cores from the 56 mm guide pilot hole revealed several clay-filled fracture zones in the otherwise hard granite. These varied from 0.5 m to 2.5 m in

16

width and could be grouted as they were encountered; assisting both further drilling and the final stability of the tunnel.

The accuracy achieved in diamond drilling was half of the specified tolerance of 0.3 %vertically, 0.5 %horizontally.

Raise boring

Once the pilot bit had broken through, a Tamrock Rhino 600 raiseboring rig was set up to ream the hole in two passes. The first pass used a 12-1;4 " raisebore pilot roller bit with a unique guidance section that followed the 0 56 mm directionally controlled core hole. It was run on standard 10" raisebore rods which were also used for the final back-reaming. For backreaming, a specially assembled cutterhead by Drill con was fitted to the 10 " rods at the break-through reaming the 12114 " hole to its final 1.8 m diameter.

The two biggest problems to be overcome in directional raiseboring are:

- following the directionally controlled core hole and removing the cuttings on the back ream.

An MSc thesis (Reitar 1992) at the University of Trondheim was made in 1992 regarding the use of guide holes, pilot holes and back reaming.

The finished tunnel required no further stabilization and has no final lining. Sewage and drinking water are piped separately inside and the tunnel itself carries storm water.

Total costs for the unlined Brerum tunnel were well under£ 1000/m. One advantage identified, was the ability to have continuous cores taken throughout the directionally controlled core-pilothole drilling.

17

3.5 STATISTICS FROM THE HORIZONTAL SHAFT AT 0

ROMSAS, OSLO

Horizontal hole diameter 0 660 mm length 101 meters.

Table 3-8. Pilot drilling statistics.

Pilot drilling lOlm Horizontal Shaft at Romsas, Norway Date Location Contractor Rock Type Machine Torque Rods Pilot Bit Reamer Cutters Inclination

Relative

Rod

#

Hole

Length

(m)

I 2 3 4 5 6 7 8 9 lO 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27

29.0 30.5 32.0 33.6 35.1 36.6 38.1 39.7 41.2 42.7 44.2 45.8 47.3 48.8 50.3 51.9 53.4 54.9 56.4 58.0 59.5 61.0 62.5 64.1 65 .6 67.1 68 .6

28 70.2 29 30 31 32 33 34 35 36 37 38 39 40 41

71.7 73.2 74.7 76.3 77 .8 79.3 80.8 82.4 83 .9 85.4 86.9 88.5 90.0

AugusUSeptember 1991 Romsas, Oslo, Norway Boliden Mineco Syenite (Nordmarkitt) Rhino 600Hx 100% =26kNm 5' /10" 11" 0.66m 2@ Sandvik -2.5°

RPM ROP Torque Force

Percentage on Bit

Bit

Torque

(kNm)

40 46 46 45

(m/h) 2.20 1.25 1.85 1.80

45 1.95 46 2.90 45 1.50 46 1.60 50 1.95 45 1.95 45 1.70 45 1.40 51 2.05 50 2.48 50 2.80 50 2.10 49 2.85 49 2.70 49 2.10 49 2.23 50 2.50 48 2.50 44 2.25 34 2.35 34 2.50 33 1.87 36 0.90

37 37 33 34

36 29 34 30 20 34 9 9

1.25 1.52 1.45 2.00

1.44 1.80

1.35 1.26 1.12 1.20 0.80

(%) (kN) 62 183.9 16.1

16.1 18.2 17.7

62 145.4 70 222.5 68 222.5 70 70 72 70 72 72 75 76 48 50 50 50 50 52 52 52 52 52 53 60 62 64 60

62 62 62 64

62 65 62 64 75 68 53

222.5 18.2 214.8 18.2 145.4 18.7 161.0 18.2 145.4 18.7 145.4 18.7 145.4 19.5 137.7 19.8 183.9 12.5 175.8 13.0 175.8 13.0 175.8 13.0 136.8 13.0 175.8 13.5 156.5 13 .5 156.5 13.5 152.7 13 .5 183.9 13.5 183.9 13 .8 214.8 15.6 191.4 16.1 164.2 16.6 138.0 15.6

145.4 16.1 176.2 16.1 153.1 16.1 176.2 16.6

214.8 16.1 175.9 16.9

16.1 145.4 16.6 161.0 19.5 130.2 17.7

13.8

Net

Penetration

(mm/rev)

0.92 0.45 0.67 0.67 0.72 1.05 0.56 0.58 0.65 0.72 0.63 0.52 0.67 0.83 0.93 0.70 0.97 0.92 0.71 0.76 0.83 0.87 0.85 1.15 1.23 0.94 0.42

0.56 0.68 0.73 0.98

0.67 1.03

0.75 1.05 0.55 2.22 1.48

Force

T1

(kN/bit) 194.9 246.6 290.5 291.6 276.4 207.8 215.2 231.6 193.8 180.6 198.0 213.4 240.2 199.6 184.1 223.0 139.7 186.1 195.9 188.2 172.4 202.1 204.6 195.5 167.1 170.6 247.4

213.3 226.8 188.5 178.5

281.5 172.0

176.2 155.8 194.2

Cutter

Coeff.

k 0.9960 1.2597 0.9294 0.9028

Cutter

Constant

c 1.0402 1.8718 1.1352 1.1057

0.9294 1.0936 0.9627 0.9392 1.4628 1.9626 1.2844 1.6869 1.4628 1.8144 1.4628 1.7213 1.5238 1.9204 1.6305 2.2643 0.7711 0.9420 0.8402 0.9241 0.8402 0.8697 0.8402 1.0042 1.0797 1.0966 0.8738 0.9118 0.9816 1.1614 0.9816 1.1270 1.0060 1.1020 0.8353 0.8966 0.8514 0.9222 0.8252 0.7688 0.9569 0.8644 1.1514 1.1848 1.2844 1.9898

1.2597 1.0395 1.1963 1.0730

0.8527 1.0916

1.3003 1.3761 1.5429

1.6787 1.2562 1.3980 1.0837

1.0443 1.0733

1.5015 1.3430 2.0822

-.c -E -c.. 0 n::

s::::: 0 ~ ns ... .... Cl) s::::: Cl) c.. ..... 0 Cl) .... ns n::

-.c -E -c.. 0 n::

s::::: 0 ~ ns ... .... Cl) s::::: Cl) c.. ..... 0 Cl) .... ns

a::

18

Piloting Romsas Horizontal Shaft 3,00

2,50

2,00

1,50

1,00

0,50

0,00

Hole Depth (m)

Figure 3-9. Rate of penetration for pilot hole drilling.

Reaming Romsas Horizontal Shaft 4,5

4,0

3,5

3,0

2,5

2,0 ...

1,5 - 1- 1--

1,0 - 1- -

0,5 - - -

0,0 I T

r-

-

1-- -

1-- -

- -

-

-

-

1-

-

0 m

I-

I-

-

-

~

-

-

-

1-

...

~ 1--

- 1--... - r- ...

1- f- 1- ~ 1- - 1-

1- - 1- - 1- - 1-

I- - I- - I- - 1-

- - - - - 1- -

I T T T

Hole Depth (m)

Figure 3-10. Rate of penetration for back reaming.

... t---

r-1-- -

r- - 1-

- 1- 1--

- 1- i-

- - -

,_

r-

'---------- --r- ... - 1-- - 1- ~

- 1-- - I- -

- 1-- - 1-- -

1- - 1-- - 1--

19

Table 3-9. Reaming statistics.

Reaming lOlm Horizontal Shaft at Romsas, Norway

Date August/September 1991 Location Romsas, Oslo, Norway Contractor Boliden Mineco Rock Type Syenite (Nordmarkitt) Machine Rhino 600Hx Torque 100% = 87kNm Rods 5'1 10" Pilot Bit 11" Reamer 0.66m Cutters 2@ Sandvik Inclination -2.5°

Relative Hole RPM ROP Force Reamer Net Force Force Force Cutter Cutter Rod Depth on Torque Penetr. on on Tl Coeff. Const.

Reamer Cutter Row # (m) (m/h) (kN) (kNm) (mm/rev) (kN/c) (kN/row)(kN/row) k c

99.1 10.0 3.5 412.9 36.0 5.83 206.5 45.9 14.1 0.4194 0.1736 2 97.6 18.0 1.7 393.6 36.0 1.57 196.8 43.7 32.3 0.4399 0.3507 3 96.1 18.0 1.8 354.2 31.5 1.67 177.1 39.4 28.0 0.4278 0.3313 4 94.6 17.5 2.0 392.7 29.3 1.90 196.4 43.6 28.4 0.3589 0.2600 5 93.0 18.0 2.2 302.9 31.5 2.04 151.5 33.7 20.9 0.5002 0.3505 6 91.5 18.0 3.3 354.2 29.3 3.06 177.1 39.4 18.7 0.3979 0.2276 7 90.0 18.0 2.2 393.2 29.3 2.04 196.6 43.7 27.2 0.3584 0.2511 8 88.5 18.0 2.8 470.7 31.5 2.59 235.4 52.3 27.7 0.3219 0.1999 9 86.9 18.0 3.5 470.7 31.5 3.24 235.4 52.3 23.9 0.3219 0.1788 10 85.4 18.0 4.2 432.2 31.5 3.89 216.1 48.0 19.4 0.3506 0.1778 11 83.9 18.0 2.2 392.7 27.0 2.04 196.4 43.6 27.1 0.3307 0.2317 12 82.4 18.0 2.2 392.7 27.0 2.04 196.4 43.6 27.1 0.3307 0.2317 13 80.8 18.0 2.4 392.7 27.0 2.22 196.4 43.6 25.6 0.3307 0.2218 14 79.3 18.0 3.4 470.7 27.0 3.15 235.4 52.3 24.3 0.2759 0.1555 15 77.8 18.0 2.2 451.4 27.0 2.04 225.7 50.2 31.2 0.2877 0.2016 16 76.3 18.0 3.4 470.7 27.0 3.15 235.4 52.3 24.3 0.2759 0.1555 17 74.7 18.0 2.7 392.7 22.5 2.50 196.4 43.6 23.7 0.2756 0.1743 18 73.2 21.0 3.3 431.7 36.0 2.62 215.9 48.0 25.2 0.4011 0.2479 19 71.7 18.0 2.2 431.7 22.5 2.04 215.9 48.0 29.8 0.2507 0.1756 20 70.2 18.0 2.1 490.5 22.5 1.94 245.3 54.5 35.0 0.2206 0.1582 21 68.6 40.0 4.5 392.7 40.5 1.88 196.4 43.6 28.7 0.4961 0.3623 22 67.1 18.0 2.4 494.0 22.5 2.22 247.0 54.9 32.2 0.2191 0.1470 23 65.6 24.0 3.0 494.0 31.5 2.08 247.0 54.9 33.6 0.3067 0.2125 24 64.1 30.0 4.2 494.0 18.0 2.33 247.0 54.9 31.2 0.1753 0.1147

20

4 DESCRIPTION OF THE METHOD AND TRB-EQUIPMENT FOR BORING HORIZONTAL DEPOSITION HOLES (0 1.68 m) AND DEPOSITION TUNNELS (0 4.0 m)

Site preparation

Site preparation for horizontal raiseboring is very similar to that of the traditional vertical or inclined applications. The general requirements are: power supply for the machine, lighting, ventilation and water supply at the work site.

The rock surface has to be cleared and cleaned for the concrete foundation~ the base plate positioned on the concrete and bolted to the rock. Normally, the base plate is locked against movement to the wall and in the case of large cutterhead diameters, turnbuckles should be used to support the machine to the wall.

All machine components are brought to the work site and prepared for boring. The machine itself must be positioned and adjusted to the desired alignment for the hole. A storage must be build for the drill rods including a rod handling device.

Pilot drilling flushing pumps, hoses and water reservoir must be circuited together for water circulation.

Figure 4-1. Reaming arrangement.

21

Pilot hole drilling is started carefully and with low penetration rates. When the first stabilizer is drilled in, then the drilling rate can be increased to approx. 1 meter/hour. The "rope effect" of the drill string must be understood in order to control the horizontal pilot hole drilling orientation successfully. The assembly at the "hole-bottom" is larger in diameter than the rest of the drill string. The weight of the rods therefore have a tendency to force the "hole-bottom" assembly upwards. This phenomena can be used to steer pilot hole drilling.

When the feed pressure is increased, the bit drills upwards. If the feed pressure is decreased due to the weight of the stabilizers, the pilot bit drills downwards. In long holes, even in the short 62 meter hole at the Tamrock Test Mine, stabilizers were used also along the drill string in addition to the ones straight after the pilot bit.

22

5 MACHINES- HORIZONTAL RAISEBORING

The basic Rhino machine design is already suitable for horizontal operation:

- Machine mounting and support in horizontal position is built into Rhino models. The concrete pad must be tilted according to machine model.

- Flushing through the machine during pilot hole drilling and in addition to higher flushing volumes during reaming is required.

Rhino 418 H for boring horizontal deposition holes

The recommended machine for the 1.68 meter diameter deposition holes is the Rhino 418 H with modified mounting and transportation equipment.

3160

Figure 5-1. Rhino 418 H basic measurement drawing.

23

Figure 5-2. Special Rhino design for horizontal holes.

Table 5-1. Dimensions and Weights of the Standard Rhino 418 H.

COMPONENT LENGTH WIDTH HEIGHT WEIGHT (mm) (mm) (mm) (kg)

BORER UNIT

- WHILE BORING 3 160 1 730 3 775 11 000

- IN TRANSPORT 3 685 1730 1 515 10 000

GEARBOX 1 365 1 590 1 430 4 000

FRAME 1 200 1 730 3 685 3 300

BASE FOOT 2000 1 444 395 570

HYDRAULIC CYLINDER 1 975- 720 310 900 2 129

TURNBUCKLE (90- 54) 2 510 140 76

DRILL ROD MANIPULATOR 1 500 1 370 600 490

HYDRAULIC POWER UNIT 2000 1 370 830 1 000 top part

HYDRAULIC POWER UNIT 2000 1 370 930 2 375 lower part, 132 kW without hydraulic oil 1700

OPERATOR'S CONSOLE 900 800 1 230 120

TOOL BOX 1 000 760 870 110 with special tools 350

24

Table 5-2. Specifications for Rhino 400 raiseborer.

SERIE RHINO 400 MODEL 418 H

RAISE DIAMETER (depending of rock type)

RAISE LENGTH (depending on rock type)

ROD -diameter -length (net) -thread DI-22

STABILIZER -diameter - length (net)

PILOT HOLE -diameter

DRIVE SYSTEM- HYDRAULIC MOTOR

GEAR BOX- SPUR GEARS

- Piloting - Reaming

-TORQUE operating at 13 RPM max (220 bar)

- HUCK THREAD: DI-22

- WEIGHT: (including motor)

REAMING THRUST ( 320 bar)

FEED RATE -up -down

RAPID TRAVERSE - up -down

ANGLE FROM HORIZON -optional

BORER UNIT WEIGHT - in transport

HYDRAULIC POWER UNIT other voltages available

:-WEIGHT

1.2- 1.8 m 2.1 m

300m

254mm 1.524 m

280mm 1.424 m

280mm

0- 240 bar

total ratios

1: 2.23 1:7.76

90kNm 120 kNm

8-114 inch

4000 kg

2000 kN

6m/h 12 m/h

3 m/min 5.7 m/min

55 to 90° 23 to 90°

11 000 kg 10 000 kg

380V 132kW

2 375 kg + 1 000 kg

4-6ft 7ft

984ft

10 inch 5

8-114 inch

11 inch 56 inch

11 inch

0- 135 RPM

range

0-32-46 RPM 0- 13- 17 RPM

50Hz

25

Rhino 2006 DC for horizontal deposition tunnels

Table 5-3. Specifications for Rhino 2000 raise borer.

SERIE RHINO 2000 MODEL 2006 DC

RAISE DIAMETER

RAISE LENGTH (depending on rock type)

ROD -diameter - length (net) -thread DI-22

STABILIZER -diameter - length (net)

PILOT HOLE -diameter

DRIVE SYSTEM- ELECTRIC DC MOTORS

GEAR BOX- SPUR GEARS

- Piloting - Reaming

-TORQUE operating at 11 RPM max

- CHUCK THREAD: DI-22

- WEIGHT: (including motors)

REAMING THRUST(320 bar)

FEED RATE -up -down

RAP ID TRAVERSE - up -down

ANGLE FROM HORIZON -optional

BORER UNIT -WEIGHT - in transport

ELECTRIC POWER UNIT -WEIGHT

HYDRAULIC POWER UNIT -motor -WEIGHT

2.13- 6.10 m 7-20ft

600m

327 mm 1.524 m

349mm 1.424 m

349mm

2*145 kW

total ratios

1: 60 1: 244

1968 ft

127/8inch 5ft

10-V2 inch

13-% inch 56 inch

13-%inch

0-2600 RPM

speed range

0-44 RPM 0- 11 RPM

411 kNm 700kNm

10-Y2 inch

12700 kg

6400 kN

3 m/h 5 m/h

1.8 m/min 3.6 m/min

63 to 90° 15 to 90

25600 kg 23000 kg

380-600V 400kVA 1600 kg

575 V 55 kW 2400 kg

26

S927.4

Figure 5-3. Transportation measurements of Rhino 2006 DC.

Table 5-4. Dimensions and Weights of the Standard Rhino 2006 DC.

COMPONENT LENGTH WIDTH HEIGHT WEIGHT mm mm mm kg

BORER UNIT - WHILE BORING 2 600 2005 3 805- 5 400 25 600 - IN TRANSPORT 3 755 1935 2050 23 000

GEARBOX 1900 1 870 2 650 12 700

FRAME 3 800 1900 1 800 6 700

BASE FOOT 265 500 2 600 2* 600

HYDRAULIC CYLINDER 2 780 370 1000

TURNBUCKLE (90- 63) 865 150 115

DRILL ROD MANIPULATOR 2050 800 840 1400

BASE BEAMS (optional) 5 800 720 550 2*3 350

ELECTRIC POWER UNIT 2 200 1000 1 250 1 600

HYDRAULIC POWER UNIT 2 200 1 000 1500 2400

OPERATOR'S CONSOLE 750 700 1 000 100

TOOL BOX 1 000 760 870 200

CRAWLER incl. power pack 6100

27

Drill String

Drill rods, stabilizers and pilot sub are called with one name in raiseboring, drill string.

Drill Rods

For different machine sizes there are different drill rod. The present standard drill rod sizes are listed in the table below.

c B

--------.----.-- .... ~ F E

Figure 5-4. Drill rod drawing.

Table 5-5. Drill rods - dimensions.

Thread A B c D E F Weight DI-22 mm mm mm mm mm mm mm kg

6-3/4" 203 1219 140 125 70 41 175 170 8-114" 254 1524 149 125 70 41 203 320 9-1/4" 286 1524 162 125 76 41 229 460 10-112" 327 1524 203 135 100 63 267 620

Rhino 418 H uses 254 mm= 10" rods Rhino 2006 DC uses 327 mm= 12-7/8" rods

Stabilizers

The stabilizer diameter is the same as the pilot bit diameter and for 1 0" rods 280 mm or 11" bit and stabilizers are selected due to the horizontal boring.

Standard raiseboring drill string are used also in horizontal applications. However, spiral stabilizers are preferred to straight rib stabilizers.

28

c 8

Figure 5-5. Stabilizer drawing.

Table 5-6. Stabilizers - dimensions.

Thread A B c D E F Weight DI-22 mm mm mm mm mm mm mm kg

6-3/4" 251 1120 270 203 70 41 175 300 8-1/4" 280 1424 300 254 70 41 203 400 8-1/4" 311 1424 320 286 70 41 203 600 9-1/4" 311 1424 320 286 76 41 229 600 10-1/2" 349 1424 420 327 100 63 267 700

Pilot sub

The pilot sub is the connecting piece between stabilizers and the pilot bit. The male thread is standard DI-22 and size according to the stabilizer thread and the female thread is standard API for pilot bit.

Also a check-valve is mounted inside the pilot sub. The valve prevents the flushing media and the cuttings from going up the stabilizers during the periods when the flow is off.

Cutterhead and cutters

In normal raiseboring where back reaming is done upwards , the crushed rock from the face falls on the head and goes through the openings in the head and falls down the raise.

In horizontal boring mucking has to be handled in two stages:

1. Special care has to be taken to clean the boring face. The best way to clean the face is to spray water from special nozzles on the head to the rock face. This water is normally provided to the head through the drill string.

29

A clean rock face results in improved penetration rates and in addition, cutterhead rotation is smoother when operating clean face.

2. The muck has to be moved from the face and from the bottom of the hole to behind the cutterhead. If this muck removal is not effective, the gage cutters will recut the muck in the hole invert. This muck actually acts like solid rock when hit by a gage cutter, causing excess stresses to the cutterhead, to the stem and to the rest of the drill string.

Normally the head is equipped with wings to push the wet muck behind the head.

Large diameter reaming heads are often equipped with a stabilizing system, i.e. rollers on the gage of the he'ad support ageinst the hole wall. This will diminish the load and wear on stabilizers and it will also help to keep reamer in alignment with pilot hole.

Cutters used in horizontal raiseboring are normal serial production raiseboring equipment.

Figure 5-6. Sandvik Horizontal 4 meter diameter cutterhead.

30

Muck removal

The first part of mucking is already taken care by the cutterhead, which has jet nozzles for flushing the face and scraping wings to transport the muck behind the head.

Mucking arrangements after the reamer head depend on the circumstances:

Inclined holes:

If there is any inclination, water flow can be used for mucking. Water brought to the head through the drill string will flush the cuttings out from the hole. For large diameter holes or in more shallow angles additional water can be pumped through the annulus between the pilot hole and the drill rods or it can be provided with a separate hose which follows the head.

Absolutely horizontal holes:

In absolutely horizontal holes, the "on the head" arrangements are same. Flushing the rock face with spray nozzles and the wings on the head to move the muck from the rock face to the back of the reamer.

1. In small diameter holes (limited space, relatively small amount of muck/hour) a scraper/winch system is normally used.

An electric or pneumatic winch is used to tow a set of scrapers back and forth in the bore to bring the cuttings out from the hole. Depending on the situation there can be one scraper that travels from the head to the other end of the hole or with shorter stroke there can be more scrapers working for shorter distance.

In short holes I big wincing capacity; only one scraper is required.

2. Mucking with suction systems

Suction systems can be used for mucking as one alternative. Water and the attashment wings first bring the muck behind the head. From there the suction system takes over. The suction nozzle is formed to follow the wall of the hole. It is attached to the head, so that it follows the head where the scraper wings bring out the cuttings.

The suction pipe should be extendible while the head advances. Suction pump and the settling arrangement is located outside the hole.

31

3. Screw conveyor

A screw conveyor attached to the head is another possibility to remove the cuttings out behind the head. The water amount has to be adequate to dilute the muck enough for the screw and the pipe transport.

4. Belt conveyor

The head can also be designed in such a way that the wings do not only push the muck behind the head, but the lift it up and dump it from the upper position. The dumping position is the start of the belt conveyor. The whole belt system is towed by the head. Extension belts are used as required as the head advances.

5. Water and pressurized air

This method is as follows; the reamer head tows a plug which seals the hole. Down in the plug there is a hole and a hose out from the hole. Flushing water is lead through the string and additional pressured air added in the annulus between the pilot hole and the drill rods.

The water cleans the face, wings move the muck behind the head and then the over-pressure drives the muck through the pipe.

6. Loader

When the hole is large enough, even a LHD can be used for mucking. LHD 's were used in the Leister Mine.

Figure 5-7. Scaper loading.

32

Pilot drilling - Drilling accuracy

Water or mud is the recommended flushing media for pilot hole drilling. Air, which can be used in vertical applications, would not transport the cuttings very well: cuttings would fall to the bottom of the hole and the air flow through the top part of the hole.

In traditional raiseboring operations the direction of the hole can be controlled up or down by adjusting the feed pressure. The hole direction has to be monitored in order to make these corrections. In sideways direction, the pilot hole has a tendency to turn to the right due to the rotation. Especially a sudden increase of the rotation has a tendency to boost the right turn.

Traditional pilot drilling of short holes (50 to 100 meters) usually results in 1 to 2% accuracy. H improved accuracy is required, it can be achieved using the steerable core drilling device.

The work begins with site preparation. The foundation has to be built so that both rigs, core drilling machine and raiseboring machine, can drill with same ax1s.

The drilling procedure begins with a 56-72 mm core drilled guide hole using a VIC DRILL Head, that can be steered and a standard core drill. The small core guide hole can be drilled with high accuracy. Normally the deviation of horizontal holes is less than 0.5 %even when the holes are longer than 300 meters.

When guide hole has been drilled through with core drilling, the core drill is replaced with a raiseborer. The raiseborer drills a 0 229-327 mm pilot hole. The pilot bit is equipped with a guide bar which follows the small guide hole. It is recommended to have guide rods (core drilling rods) in the whole length of the hole. This prevents the guide hole from collapsing and guide rod failures can be detected right away (potential deviation).

The learning curve is also one way to achieve accurate holes. It can be used when the amount of holes to be drilled is substantial. The first hole is drilled in a professional way recording all machine parameters (included in Rhino machines) and also recording all other events and changes during drilling. When in the same rock the next hole is drilled using exactly the same procedure; the hole will make exactly the same path or the hole can be turned to hit the target by compensating the deviation by adjusting machine parameter settings.

33

Figure 5-8. Pilot bit with the core hole guide bar.

Modification of equipment for boring deposition tunnels

Typically the horizontal adjustment is provided by placing the machine base plate on a tilted concrete foundation and fine-tuning by the machine turn buckles.

Machines for the large diameter holes can be standard Rhino. All features required in horizontal boring are already included in the machine.

Smaller machines for boring deposition holes have some special requirements. The amount of holes is big enough to justify special designs. In addition, requirements as to effective production will require machines to be tailor-made. The boring takes place from a tunnel already made by raiseboring. The special characteristics of this can be utilized when designing the boring station. It will also brings space limitations, everything

34

has to fit in and operate in the hole diameter. The benefits of the round, uniform shape can be used. Accurate and fast positioning of the machine can be done by supporting the boring station to the round tunnel walls with hydraulic jacks. There is no need for using bolts to attachment the unit to the rock. This will make production faster (set up time is minimized) and also save money when bolts and concrete are not reguired.

If the deposition holes are made to a vertical position from the tunnel, then less modifications to the machine is required. All the equipment needed for downwards blind boring should be built into one integrated machine. To solve the logistic problems, this machine should be self propelled and carry everything onboard. Transportation of the muck by the vacuum process should be a separate unit due to the large capacity requirement.

Space requirements of the raiseboring machine to bore deposition holes using a standard unit are tunnel height min. 3.6 m and tunnel width min 5.3 m. Special tailored machine for deposition hole boring would need a tunnel diameter of 4.5 m or 4.5 m x 4.5 m tunnel (height x width).

Special considerations

Using raiseboring for excavating horizontal tunnels is an extension of the traditional raiseboring practice, but a proven method which has been used several times in many countries since 1973.

All necessary equipment for horizontal raiseboring are commercially available.

The success of the operation will mainly depend on aspects assisting raiseboring operation, i.e.

• Direction control has to be tn accordance of the design requirements of the deposit plant.

• Mucking during boring has to be effective enough to allow the raise boring machine to be used to its full capacity.

35

6 PERFORMANCE PROGNOSIS

The performance estimates shown in Figures 6-1 and 6-2 and Tables 6-3 and 6-4 are made using the present machine models (Table 6-2) and Sandvik reamer heads and cutters as the base for the calculations (Appendix 1). The main rock types considered at the three investigation sites were Quartz Diorite Gneiss, Quartz Diorite, Granodiorite and Micagneiss. The properties of these are shown in Table 6-1.

Table 6-1. Properties of the main rock types at the three investigation sites.

Rock type

Quartz Diorite Gneiss

Quartz Diorite

Granodiorite

Micagneiss

Compressive Strength

(MP a)

244

92

105

125

Vickers Rock Hardness Information (VHNR) Accurancy

796 30%

599 30%

722 30%

724 30%

Table 6-2. Machine specifications.

Raise boring Machine Machine Drill Rod Reamer Number Machine Thrust Torque diameter diameter of

(tons) (kNm) (inches) (m) Cutters

Rhino 2006D 640 450 12 7/8 4.44 24

Rhino 418 H 200 90 10 1.83 10

36

10,0 1 Rhino 41BH f I I I I I I Granodiorite

-..£: -E -- Quartz Diorite y = 0.0003x1

·69

- y = 0.0005x1·61

/ c: 0

:;:; m '-- 1,0 Q) c: Q)

1\

~J¥ 1\

Hf I

riTT 7 I) 7 7

a. I/ ,_ -0 Q)

v" I " // 7

"" -m ~

0::: I-- Micagneiss Quartz Diorite Gneiss I-- y = 0.0001x1

·81

y = 6E-06x2.29

0,1 I 10 100 1000

Force on Reamer (tonnes)

Figure 6-1. Performance estimate for boring deposition holes (0 1.68 m) using Rhino 418 H raiseboring machine.

Table 6-3. Performance estimates for boring deposition holes (0 1.68 m) using Rhino 418 H raiseboring machine.

Rock Penetration Cutter Cutter Rotation Thrust Torque type Rate Life Load Speed utilized utilized

(m/h) (m) (tonnes) (RPM) (%/tonnes) (%/kNm)

QDG 0.63 738 15.0 5 77/154 89/80 QD 0.97 1469 11.0 5 571114 81173 G 1.01 1443 12.0 5 621124 90/81 MG 0.87 1243 12.0 5 62 I 84 I

QDG = Quartz Diorite Gneiss QD = Quartz Diorite G = Granodiorite MG = Micagneiss

37

10,0 J Rhino 2006 DC :

l I Quartz Diorite Quartz Diorite

-.c -E -y = 9E-05x1

.64 Gneiss

y = 6E-07x2·34

\. c:: 0

+= a:s loo - 1,0 Cl) c:: Cl) 0.. -0 Cl) -a:s a:

"\ I

"\. ~ / r---- Granodiorite ~J r----- //. ... r-----y = 6E-05x1

.71 1-t- I// r----- - ~I I r----

I • I / ij I / I

Micagneiss

y = 2E-05x1·84

0 ,1 11

10 100 1000

Force on Reamer (tonnes)

Figure 6-2. Performance estimate for boring deposition tunnels (0 4 m) using Rhino 2006D raiseboring machine.

Table 6-4. Performance estimates for boring deposition tunnels (0 4 m) using Rhino 2006D raiseboring machine.

Rock Penetration Cutter Cutter Rotation Thrust Torque type Rate Life Load Speed utilized utilized

(m/h) (m) (tonnes) (RPM) (%/tonnes) (% I kNm)

QDG 0.46 294 13.0 5 51 I 326 90 I 405 QD 0.97 959 11.0 5 43 I 215 94 I 423 G 0.88 672 11.0 5 43 I 275 90 I 405 MG 0.81 616 11.5 5 45 I 90 I

QDG =Quartz Diorite Gneiss QD = Quartz Diorite G = Granodiorite MG = Micagneiss

38

7 SUMMARY AND CONCLUSIONS

Horizontal raiseboring has been used successfully from the early 1970' to make relatively short (less than 500 meters) and reasonable sized (4.5 meters) holes in different type of rocks. Experience shows that the method is applicable for KBS-3 type deposition tunnels and also for the smaller diameter horizontal deposition holes in the MLH concept.

Some of the benefits of the method are:

- small disturbance to the surrounding rock - constant circular shape - low investment cost (compared to TBM's) - short set-up time (compared to TBM's) - good performance.

One of the main limitations of the method, which also reduces its flexibility when compared to Drill and Blast is the need for access to both ends of the tunnel. Although the performance of the method was estimated, overall field performance is very dependent on the efficiency of the removal system for cuttings, which could not be estimated reliably on the basis of the presented case studies.

39

8 REFERENCES

Autio, J. 1992. Techni~al feasibility of horizontal disposal concepts for final disposal of TVO's spent fuel. TVO/Spent Fuel-Safety and Technology, work report 92-08. Teollisuuden Voima Oy (TVO), Helsinki, 50 p (In Finnish).

Autio, J. & Kirkkomaki, T. 1996. Boring of full scale deposition holes using a novel dry blind boring method. Report POSIV A-96-07, Posiva Oy, Helsinki.

Autio, J., Saanio, T., Tolppanen, P., Raiko, H., Vieno, T. & Salo, J-P. 1996. Assessment of alternative disposal concepts. Report POSIV A-96-09, Posiva Oy, Helsinki.

Riekkola, R. & Salo, J.-P. 1996. Final repository for spent nuclear fuel. Technical research and development in the period 1993 - 1996. Work report TEKA-96-09, Posiva Oy, Helsinki (In Finnish).

SKB 1992. Project on Alternative Systems Study (PASS) - Final report. Stockholm, Swedish Nuclear Fuel and Waste Management Co (SKB), Technical Report 93-04 (In Swedish).

Posiva 1996. Final disposal of spent nuclear fuel in the Finnish bedrock, Technical research and development in the period 1993- 1996. Report POSIV A-96-14, Posiva Oy, Helsinki (In Finnish).

Reitar, R. 1996. Micro Tunnels. MSc Thesis, University of Trondhein. 168 p. (In Norwegian)

TVO 1992a. Final disposal of spent nuclear fuel in the Finnish bedrock. Technical plans and safety assesment. Report YJT-92-31E. Nuclear Waste Commission of Finnish Power Companies, Helsinki. 136 p.

TVO 1992b. Final disposal of spent nuclear fuel in the Finnish bedrock. Preliminary site investigations. Report YJT-92-32E. Nuclear Waste Commission of Finnish Power Companies, Helsinki. 322 p.

Appendix 1. 1 I 8

TAB-Raise Borers' performance estimation for: POSIV A Oy

Quotation RB 2 010/95

Rock Classification: Rock type:

Selected values Compressive Stregth UCS: Vickers Hardness

Rock Information Accuracy

Rock Mass Nature

Hole Length Hole agnle from horizontal Hole diameter

Raise Boring Machine Machine Thrust Machine Torque

Drill Rods Drill Rod Thread Dl-22

Effecive dead weight

Intermediate Quartz Diorite Gneiss

244 MPa 796 VHNR

is selected to vary +1-

Massive

120 m 0 degrees

4,44 m

Rhino 2006 DC 640 tonnes 450 kNm

12-7/8 10-1/2 11

Reamer Head 4,44 m with

0 tonnes

24 cutters 5 RPM

Sandvik 111

Head Rotation Speed Cutters Cutter Load

PERFORMANCE ESTIMATION:

Penetration Rate

Cutter Wear Life

Muck Produced

13 tonnes

0,46 m/h

294 m

7,1 m3/h

Performance and needed power according to the cutter load

Cutter Thrust Torque load utilized utilized 3 RPM [ton] [%] (o/o] [m/h]

11,0 43 °/o 76 °/o 0,19 11,5 45 °/o 79 °/o 0,21 12,0 47 °/o 83% 0,23 12,5 49% 86% 0,25

>>>> 13,0 51 °/o 90% 0,27 13,5 53 °/o 93 °/o 0,30 14,0 55 °/o 97 °/o 0,32 14,5 56 °/o 100% 0,35 15,0 58 °/o 104% 0,38 15,5 60 °/o 107 o/o 0,41 16,0 62 o/o 110°/o 0,44

date 17.3.1997 rei. 5361-TRB

Usual Range for the Rock Low 150 High 300 MPa Low 750 High 900 VHNR

Range of selected accuracy Low 171 High 317 MPa Low 557 High 1035 VHNR

30%

= Horizontal

51 % Utilized 90 % Utilized

inches 88% Utilized

Possible diversity due to variation in rock information 0,29 m/h to 0,74 m/h

139 meters to 492 meters

Penetration rate at 5 RPM 7 RPM [m/h] [m/h]

0,31 0,44 0,35 0,49 0,38 0,53 0,42 0,59

>> 0,46 << 0,64 <<<<< 0,50 0,70 0,54 0,76 0,58 0,82 0,63 0,88 0,68 0,95 0,73 1,02

Appendix 1. 2/8





Siliceous Granodiorite

105 MPa 722 VHNR


Rock Mass Nature






Reamer Head 4,44 m with Head Rotation Speed Cutters Cutter Load


Penetration Rate

Cutter Wear Life

Muck Produced

Massive

120 m 0 degrees

4,44 m


12-7/8 10-1/2 11

0 tonnes

24 cutters 5 RPM

Sandvik 111

11 tonnes

0,88 m/h

672 m

13,6 m3/h


Cutter Thrust Torque load utilized utilized 3 RPM [ton] [%] [%] [m/h)

9,0 36% 73% 0,38 9,5 38 °/o 77 °/o 0,41 10,0 40 °/o 81% 0,45 10,5 41% 85% 0,49

>>>> 11,0 43% 90 °/o 0,53 11,5 45% 94% 0,57 12,0 47 °/o 98 °/o 0,61 12,5 49 °/o 102% 0,65 13,0 51% 106% 0,69 13,5 53% 110% 0,74 14,0 55% 114% 0,78

date 17.3.1997 rei. 5361-TRB



30%

= Horizontal

43 % Utilized 90% Utilized

inches 87% Utilized



Penetration rate at 5 RPM 7 RPM [m/h) [m/h)

0,63 0,88 0,69 0,96 0,75 1,05 0,81 1 '14

>> 0,88 << 1,23 <<<<< 0,94 1,32 1,01 1,42 1,08 1,52 1 '15 1,62 1,23 1,72 1,30 1,83

Appendix 1. 3/8

TRB-Raise Borers' performance estimation for: POSIV A Oy




Micagneiss

125 MPa 724 VHNR


Rock Mass Nature






Reamer Head 4,44 m with Head Rotation Speed Cutters Cutter Load


Penetration Rate

Cutter Wear Life

Muck Produced

Massive

120 m 0 degrees

4,44 m


12-7/8 10-1/2 11

0 tonnes

24 cutters 5 RPM

Sandvik 1" 11,5 tonnes

0,81 m/h

616 m

12,5 m3/h


Cutter Thrust Torque load utilized utilized 3 RPM [ton] [%] [%] [m/h]

9,5 38% 74% 0,35 10,0 40% 78% 0,38 10,5 41% 82% 0,41

>>>> 11,0 43% 86% 0,45 11,5 45% 90% 0,49 12,0 47 o/o 94% 0,52 12,5 49 °/o 98% 0,56 13,0 51 °/o 102% 0,60 13,5 53 °/o 106% 0,64 14,0 55 °/o 110% 0,69 14,5 56 °/o 113% 0,73

date 19.09.1997 rei. 5361-TRB



30%

= Horizontal

45% Utilized 90 % Utilized

inches 88 °/o Utilized

Possible diversity due to variation in rock information

0,61 m/h to 1,08 m/h


Penetration rate at 5 RPM 7RPM [m/h] [m/h]

0,58 0,81 0,63 0,89 0,69 0,97 0,75 1,05

>> 0,81 << 1 '13 <<<<< 0,87 1,22 0,94 1,31 1,00 1,41 1,07 1,50 1 '14 1,60 1,22 1,70

Appendix 1. 4/8






Rock Mass Nature





Intermediate Quartz Diorite

92 MPa 599 VHNR


Massive

120 m 0 degrees

4,44 m


12-7/8 10-1/2 11

0 tonnes

Reamer Head 4,44 m with 24 cutters 5 RPM

Sandvik 111

Head Rotation Speed Cutters Cutter Load


Penetration Rate

Cutter Wear Life

Muck Produced

11 tonnes

0,97 m/h

959 m

15 m3/h


Cutter Thrust Torque load utilized utilized 3 RPM [ton] [%] [o/o] [m/h]

9,0 36 °/o 77 o/o 0,43 9,5 38% 81% 0,46

10,0 40% 86 °/o 0,50 10,5 41 °/o 90% 0,54

>>>> 11,0 43 °/o 94% 0,58 11,5 45% 99% 0,63 12,0 47% 103% 0,67 12,5 49% 107% 0,71 13,0 51 °/o 111 % 0,76 13,5 53 °/o 116% 0,80 14,0 55% 120% 0,85

date 17.3.1997 rei. 5361-TRB



30%

= Horizontal

43% Utilized 94 °/o Utilized

inches 91 % Utilized


0,78 m/h to 1,21 m/h



0,71 0,99 0,77 1,08 0,84 1 '17 0,90 1,27

>> 0,97 << 1,36 <<<<< 1,04 1,46 1 '11 1,56 1 '19 1,66 1,26 1,77 1,34 1,88 1,42 1,99

Appendix 1. 5/8



date 17.3.1997 rei. 5361-TRB

Rock Classification: Intermediate Usual Range for the Rock Rock type: Quartz Diorite Gneiss Low 150 High 300 MPa


244 MPa 796 VHNR

Low 750 High 900 VHNR



Rock Mass Nature

is selected to vary +1- 30%





Reamer Head 1 ,83 m with Head Rotation Speed Cutters Cutter Load


Penetration Rate

Cutter Service Life

Muck Produced

Massive

120 m 0 degrees =Horizontal

1,83 m

Rhino 418 H 200 tonnes 77 % Utilized

90 kNm 98% Utilized

10 inches 8-1/4 " 41 °/o Utilized

0 tonnes

10 cutters 5 RPM

Sandvik 1" 15 tonnes


0,63 m/h

738 m

1,7 m3/h

0,42 m/h to 0,98 m/h



Cutter Thrust Torque Penetration rate at load utilized utilized 3 RPM 5 RPM 7 RPM [ton] [%] [%] [m/h] [m/h] [m/h]

13,0 67% 77% 0,27 0,46 0,64 13,5 69 °/o 80% 0,30 0,50 0,70 14,0 72% 83% 0,32 0,54 0,76 14,5 74 °/o 86% 0,35 0,58 0,82

>>>> 15,0 77 o/o 89% 0,38 >> 0,63 << 0,88 <<<<< 15,5 79 o/o 92% 0,41 0,68 0,95 16,0 82 o/o 95% 0,44 0,73 1,02 16,5 84 °/o 98% 0,47 0,78 1 '1 0 17,0 87% 101% 0,50 0,84 1 '17 17,5 89% 104% 0,54 0,89 1,25 18,0 92% 107% 0,57 0,95 1,33

Appendix 1. 6/8





Siliceous Granodiorite

105 MPa 722 VHNR


Rock Mass Nature








Penetration Rate

Cutter Service Life

Muck Produced

Massive

120 m 0 degrees

1,83 m

Rhino 418 H 200 tonnes

90 kNm

10 8-1/4 11

0 tonnes

10 cutters 5 RPM

Sandvik 111

12 tonnes

1,01 m/h

1443 m

2,7 m3/h


Cutter Thrust Torque load utilized utilized 3 RPM [ton] [%] [o/o] [m/h]

10,0 52 °/o 75% 0,45 10,5 54% 79% 0,49 11,0 57% 83% 0,53 11,5 59 °/o 86% 0,57

>>>> 12,0 62% 90% 0,61 12,5 64% 94% 0,65 13,0 67% 98% 0,69 13,5 69 °/o 101% 0,74 14,0 72 °/o 105 o/o 0,78 14,5 74 °/o 109% 0,83 15,0 77 °/o 113°/o 0,88

date 17.3.1997 rei. 5361-TRB

Usual Range for the Rock Low 100 High 250 MP a Low 775 High 925 VHNR


30%

= Horizontal

62% Utilized 99% Utilized



0,8 m/h to 1 ,28 m/h



0,75 1,05 0,81 1,14 0,88 1,23 0,94 1,32

>> 1,01 << 1,42 <<<<< 1,08 1,52

1 '15 1,62 1,23 1,72 1,30 1,83 1,38 1,93 1,46 2,05

Appendix 1. 7/8





Micagneiss

125 MPa 724 VHNR


Rock Mass Nature








Penetration Rate

Cutter Service Life

Muck Produced

Massive

120 m 0 degrees

1,83 m


90 kNm

10 8-1/4 11

0 tonnes

10 cutters 5 RPM

Sandvik 1" 12 tonnes

0,87 m/h

1243 m

2,3 m3/h


Cutter Thrust Torque load utilized utilized 3 RPM [ton] [%] [%] [m/h)

10,0 52% 70% 0,38 10,5 54% 73% 0,41 11,0 57% 77% 0,45 11,5 59% 80% 0,49

>>>> 12,0 62% 84% 0,52 12,5 64% 87% 0,56 13,0 67% 91 °/o 0,60 13,5 69% 94 °/o 0,64 14,0 72% 98% 0,69 14,5 74% 101% 0,73 15,0 77% 105% 0,78

date 19.9.1997 rei. 5361-TRB



30%

=Horizontal

62 °/o Utilized 92 % Utilized

inches 38% Utilized



Penetration rate at 5 RPM 7 RPM [m/h) [m/h)

0,63 0,89 0,69 0,98 0,75 1,05 0,81 1 '13

>> 0,87 << 1,22 <<<<< 0,94 1,31 1,00 1,41 1,07 1,50 1 '14 1,60 1,22 1,70 1,29 1,81

Appendix 1. 8/8


Quotation RB 2,010/95




Rock Mass Nature





Intermediate Quartz Diorite

92 MPa 599 VHNR


Massive

120 m 0 degrees

1,83 m


90 kNm

10 8-1/4 11

Reamer Head 1 ,83 m with

0 tonnes

10 cutters 5 RPM

Sandvik 1" Head Rotation Speed Cutters Cutter Load


Penetration Rate

Cutter Service Life

Muck Produced

11 tonnes

0,97 m/h

1469 m

2,6 m3/h


Cutter Thrust Torque load utilized utilized 3 RPM [ton] [%] [%] [m/h]

9,0 47 °/o 66 °/o 0,43 9,5 49% 70% 0,46 10,0 52% 74% 0,50 10,5 54% 77% 0,54

>>>> 11,0 57% 81% 0,58 11,5 59% 85% 0,63 12,0 62% 88 °/o 0,67 12,5 64% 92 °/o 0,71 13,0 67% 96% 0,76 13,5 69% 99% 0,80 14,0 72% 103% 0,85

date 17.3.1997 rei. 5361-TRB



30%

= Horizontal

57% Utilized 89% Utilized



0,78 m/h to 1,21 m/h


Penetration rate at 5 RPM ?RPM [m/h] [m/h]

0,71 0,99 0,77 1,08 0,84 1 '17 0,90 1,27

>> 0,97 << 1,36 <<<<< 1,04 1,46

1 '11 1,56

1 '19 1,66 1,26 1,77 1,34 1,88 1,42 1,99

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