10/10_rock excavation handbook / planning

10. Project Planning and ImplementationROCK EXCAVATION HANDBOOK

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As shown on the above chart (FIGURE 10.1.-2.), concrete lining is very costly. The example isa real one-kilometer-tunnel (cross-section 100 m2 ), which concrete lining cost deviation is 30-50% according to design, and 50-70% because of overbreak. Therefore the object is toplan tunnel dimensions in the right place with the right surface quality. The following mat-ters should considered to achieve greater accuracy in tunneling:

- Optimized drilling and blasting pattern- Optimized equipment with skilled operators- Accurate tunnel location by using laser as reference point- Tunnel profile line manually marked or by using TCAD or Data jumbo- Drilling accuracy using precise instrumentation, ref. TAMROCK

Measurement System TMS, TCAD, etc...- Accurate charging with high-quality explosives and detonators- Result follow-up-modifications to drilling and blasting pattern

Optimization is the key to a successful project. (FIGURE 10.1.-3.) Should you select moreexpensive but more effective and faster equipment; or cheaper, less effective and slowerequipment? If the majority of costs comes from wages and interest, for example, rather thanfrom consumables, explosives etc., then it is more important to choose the more effectiveequipment.

When choosing equipment, quality should also be taken into account. Location accuracy,reduced overbreak, minimizing drill holes are also important.

Optimization can be attained through partnering. FIGURE 10.1.-4. shows the main aspects ofwhat a contractor can gain through partnering.

FIGURE 10.1.-2. Cost relations in tunneling cycle.

10.1. PROJECT COSTS

Most costs are time related. Penalties can be very high if the project can’t keep its schedule.Savings may be significant if the project is finished ahead schedule. Equipment availability isessential to finish the project in time, but it is also important to have committed personnelat the work site. Trained operators and service people as well as spare part logistics alsoaffect the time spent on the project.

The following illustrations (FIGURE 10.1.-1. and 10.1.-2.) give an example of time and costrelations in the tunneling cycle.

FIGURE 10.1.-1. The above circle illustrates different jobs in tunneling cycle. The cost breakdown figures for differentjobs are appear in boxes.


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10.2. TAMROCK PROJECT STUDIES

10.2.1. Excavation process recommendations

Project documents often determine the excavation method, but to optimize the excavationprocess many factors must be determined. The key issue is to have a balanced fleet to opti-mize performance. Operations can be cyclic or continuous depending on the selected rockexcavation method. Factors affecting performance include rock conditions, operator experi-ence, chosen method, hauling distance etc.

Drilling rate index (DRI) is one way to determine the rock’s characteristics. A low DRI valueindicates a slow drilling penetration rate and a high DRI indicates high penetration rate. DRIvaries typically between 20 - 100. (See more in Chapter 2.3.)

Available time may vary from months to years depending of the size of the site and project,and it also greatly affects fleet size. Operator experience varies from beginner to professional,however, for example in face drilling a computerized system reduces the effect of operatorskills.

The selected method, for example, drill & blast compared to mechanized method, also affectsequipment selection. If the D&B method (example of cyclic method) is chosen, the fleet willconsist of drifting jumbos, bolters, LHD loaders and dump trucks. If mechanized and continu-ous methods are used, equipment selection may consists of TBM or roadheader and haulingwagons for example on rails.

Hauling distances can vary from hundreds of meter to kilometers depending the purpose ofthe rock and site location. This determines the hauling system. Excavated rock can be useddirectly on the same work site for filling or is hauled to the crusher or dump area to waitfuture use.

10.2.2. Equipment selection

Before equipment selection can be done, the excavation method should be selected. Somefactors in underground projects:

Following list is for underground fleet selection:

- Work schedule- Rock properties- Excavation method- Drill and blast- Road headers- TBM- Hammer

Figure 10.1.-3. Reducing costs by maximizing productivity/unit.

Figure 10.1.-4. Optimization through partnering.

OPTIMIZATION THROUGH PARTNERING

1. Applications, Operating Conditions and Processes

2. Fleet Selection

3. Fleet Management

4. Support System

Contractor’sCompetencies

Supplier Team’sCompetencies


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Following are results from tunneling study calculations:

- Penetration rates on DRI (drilling rate index) basis- Round drilling time- Loading capacity- Loading time- Bolting capacity- Bolting time- Other cycle time estimates- Charging time- Blasting and ventilation time- Concrete spraying time- Total cycle time- tunnel advance rate - long-time advance rate with single and

double heading Single heading: One drilling jumbo is working at one tunnel at the time. Double heading: One jumbo can be used in two tunnels or faceswhen drilling is done in face A the jumbo is moved to drill face B while other works (e.g. blasting, loading etc.) are under work in face A.

- Costs

- Excavators, etc.- Excavated sections, such as caverns, tunnels, shafts- Size and amount of excavated sections- Tunnel length and size such as width and height and variance

of dimensions- Advance - Operators skills- Operation cycle- Bolting- done by jumbo, robolt or other- Need for grouting/drainage holes- Loading and haulage type and distances

Some factors affecting surface projects:

- Work schedule- Rock properties- Excavation method- Purpose for excavation such as rock fill dam, production

of concrete, etc.- Size of excavated section- Hole diameter- Bench height- Required block size- Operators skills- Operation cycle- Loading and haulage type and distances

10.2.3 Performance and cost studies

TAMROCK has made some study programs as a tool for process recommendation, equipmentselection, and performance and cost studies. See attached study sheets of tunnel and surfacestudy programs. Drill and blast tunneling, surface drilling, bolting and underground loadingstudy programs are very useful for calculating construction studies. There is also an availablestudy for calculations on full-face methods such as tunnel boring machines. And Tamrockalso has a long hole study specially designed for mining.

To enable performance and cost study the above-listed facts should be identified. Local unitprices for energy, explosives etc. should also be determined.

Through these studies, performance figures can be calculated for selected equipment, andthe related total investment and operation costs.


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Project: EXAMPLELocation: QUARRYSection: BENCH

ESTIMATE OF EQUIPMENT AMOUNT

Rock production, total: 651854 699143 775494 m3

tExcavation time: 12 12 12 monthsProduction/month: 64625 58262 64625 m3/monthNeed of drill holes/month: 6359 5492 5008 drm/monthNo. of drilling units: 1 1 1One unit’s capacity is left free:0 0 0 %Tot drm in given prod: 76311 65904 60100 drmRock drill perc. h, total: 1523 1647 1724 hoursRock drill perc. h, per unit: 1523 1647 1724 hoursEngine hours, total: 2796 2796 2796 hoursEngine hours, per unit: 2796 2796 2796 hours

SUMMARY OF BLAST DATA

Mean fragment size: 310 310 310 mmHole length: 12.8 12.9 13.0 mDrill pattern: 9.1 11.4 14.0 m2

Drill burden: 2.7 3.0 3.3 mOn surface: 2.7 3.0 3.3 mDrill spacing: 3.4 3.8 4.2 mSub-drill: 0.8 0.9 1.0 mRock blastability index: 0.60 0.60 0.60Explosive:Bottom chargeType of explosive: Dynamite Dynamite DynamiteCharge distribution: 10 10 10 %Column chargeType of explosive: Anfo Anfo AnfoCharge distribution: 90 90 90 %Bottom charge length: 1.20 1.19 1.18 mColumn charge length: 10.41 10.28 10.26 mUncharged height: 1.2 1.4 1.6 mBottom charge: 7 9 11 kgColumn charge: 62 80 101 kgTotal charge per hole: 68 89 112 kgSpecific charge: 0.62 0.65 0.67 kg/m3

0.23 0.24 0.25 kg/tSpecific drilling: 8.5 10.6 12.9 m3/drm

0.12 0.09 0.08 drm/m3

23.06 28.64 34.84 t/drm0.04 0.03 0.03 drm/t

Surface Rock Drilling/Capacity

Project: EXAMPLELocation: QUARRYSection: BENCH

SITE INFORMATION

Hole diameter Hole diameter Hole diameter 89 mm 102 mm 115 mm

Rock type: Granodiorite Granodiorite GranodioriteDrillhole diameter: 89 102 115 mmBench height: 12 12 12 mHole inclination: 0 0 0 degDrilling rate index: 45 45 45

DRILLING EGUIPMENT SELECTION

Type of rig: PANTERA 900 PANTERA 900 PANTERA 900 Rock drill: HL 1000 HL 1000 HL 1000 Drilling tools: MF rods MF rods MF rods Drill rodltube size: 51 51 51 mmDrill rodltube length: 3.66 3.66 3.66 m

WORKING ARRANGEMENTS

Work days per week: 6 6 6 daysWorking days per month: 25 25 25 daysWorking months per year: 12 12 12 monthsMechanical availability: 90 90 90 %Work days per year: 290 290 290 daysTotal working time per year:4640 4640 4640 hEffective time per year: 2784 2784 2784 hUsage per year: 2506 2506 2506 hDrilling time per year: 2004 2004 2004 h

DRILL RIG PERFORMANCE

Holes per set up: 1 1 1Rods per hole: 4 (3.73) 4 (3.77) 4 (3.81)Net penetration, lst rod: 1 0.8 0.7 m/minTotal time per hole: 20.6 24.1 26.8 minDrilling capacity: 38 33 30 drm/h

2.99 2.54 2.28 holes/h27 24 21 drm/engine-h164 142 130 drm/shift329 284 259 drm/day6579 5681 5181 drm/month76311 65904 60100 drm/year


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WORKING TIME

Hours per shift: 10 hoursEffective time: 8 hours/shiftShifts per day: 2Work days per week: 6 daysWork days per month: 25 daysWorking months per year: 12 months/year

SCHEDULE AND UNIT CYCLE

Rock bolting: 42 minSteel ribs + wire mesh: minSprayed concrete: 55 minDrilling: 136 minCharging: 71 minBlast + ventilation: 30 minLoading: 101 minScaling + clear: 20 minMiscellaneous: 30 minTotal time/round: 485 min

8.1 hours

PERFORMANCE Single Double

Transfer time: 30 minLong term factor: 85 85 %Rounds per day: 2 2.9Practical advance: 6.1 8.8 m/day

37 53 m/week153 220 m/month1832 2637 m/year

Tunnel length: 1000 1000 mlnterval niches: 300 300 mExcavation time: 28 19 weeks

6.7 4.6 months

Drilling time and tunnel advance estimate scenarios

DRILLING TIME

Type of rock: GNEISSDRI: 45Density: 2.7 t/m3

Rigs parane in tunnel: 1No of operators per rig: 1Operator experience: AdvancedPenetration: 2.1 m/minDriling rate: 1.6 m/minReaming penetration: 0.9 m/minReaming time: 14 minDrilling time, incl. reaming: 121 minAuxiliary time: 15 minDrilling cycle: 136 min

CHARGING TIME

Charge total: 243 kgSpecific charge: 1.57 kg/m3

Charging crew: 3Charging cycle: 71 min/round

LOADING TIME

Eguipment: Toro 1250 D Bucket size: 6 m3

Carrying distance: 50 mLoading + hauling capacity: 200 m3 /h (loose)Swell factor: 1.6 Overbreak factor: 1.15 Total volume: 286 m3/round (loose)Loading cycle: 101 min/round

BOLTING TIME

Rock bolts/row: 5Rock bolt spacing: 2 mRock bolts/round: 9Rock bolt length: 2 mType: CementBolting cycle: 42 min

Name of project: EXAMPLELocation: TUNNELExcavated section: FULL SECTION

TUNNEL DIMENSIONS

Face area: 42.8 m2

Height: 7.5 mWidth: 6.4 mProfile length, excl. bottom: 18.7 m

DRILLING EQUIPMENT

Drilling system: Power classType of machine: PARAMATIC

205 - 90Booms: TB 90Rock drill: HL 500 SFeed: CF 145 x 14Feed length, total: 5995 mmDrill steel length: 4305 mmMax. hole length: 3.9 mNumber of booms: 2Coverage, height: 8.51 mwidth: 12.82 m

DRILLING DATA

Hole diameter: 45 mmCut type: ParallelReamed hole diameter: 102 mmNumber of holes: 79 + 2Hole length: 3.9 mDrilled meters: 324 mPull length: 93 %Advance: 3.6 m/roundSpecific drilling: 2.09 drm/m


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PERIODIC MAINTENANCE

After commissioning, in whichthe equipment is checked, testedand adjusted to match local siteconditions, it is important to fol-low the manufacturer´s periodicmaintenance instructions to maxi-mize equipment availability. Theinstructions consist of a per-shiftinspection, and weekly andmonthly maintenance. Mostequipment operators perform theper-shift inspection, and mainte-nance personnel perform theweekly and monthly maintenance.Good information flow betweenoperators and maintenance per-sonnel is vital for optimummachine maintenance and per-formance.

Periodic maintenance is based onoperating hours and typically ahalf shift per week is required to

FIGURE 10.3.-2. Tamrock training enhances both operational and technical skills.

FIGURE 10.3.-3. Properly performed periodic maintenance maximize equipment availability.

10.3. SERVICE SUPPORT

Proper equipment selection on the construction site is very important, however, this alonecan not ensure the success of a project. More important, if not critical, is equipment fleet management and service support. This chapter lists key elements related to equipment sup-port and describes some of the service offering available from Tamrock.

In order for the selected to operate as efficiently as possible, certain elements must be ensured:

- Competent operators- Knowledgeable servicemen and mechanics- Planned service operation- Timely spare parts and components- Quality service work

These elements are achieved through proper service support.

TRAINING

The main objective of training is to enhance both operator and maintenance personnel skills,therefore, maximizing machine performance and availability. Both theoretical and hands-ontraining is needed to get the best result. Training is often customized according to localneeds. The Tamrock classification system helps to identify present skills levels and targetedtraining needs.

Initial training is typically given on-site during start-up. More comprehensive training can beprovided at Tamrock plants or at some of the regional training centers where cut-away components, videos and computer animation assist understanding and make the trainingmore illustrative.

FIGURE 10.3.-1. Competent operators, knowledgeable servicemen and mechanics are impor-tant for ensuring the high productivity of the selected equipment.


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Tamrock’s worldwide computer software system and Tamrock-developed electronic tools suchas Rocknet, Paris, RockSite, RockDoc and RockTionary support all spare part inquiries, ordering, handling, delivering and consumption follow-up. Electronic spare part manuals andmaintenance instructions make information handling easier and more illustrative.

SERVICE FACILITIES AND TOOLS

The workshop should be equipped with sufficient crane, welding machines, steam cleaningunits, hand tools, hose crimping machines, grinders, presses, cutting torches, testing and measuring devices, working benches and tool panels. There should also be a dedicated placefor all necessary fuel, grease, oils, lubricants and solvents. The storage facility should containsufficient shelving with necessary bins, dividers and racks to accommodate the spare partsand components. This location shall be lockable and dry.

Where qualified and quick service set-up is needed, portable service containers provide theideal solution for workshop, spare parts and tools storage. Tamrock service containers areequipped with a selection of tools and accessories to meet all Tamrock equipment service andmaintenance requirements. The containers can be equipped with air conditioning or heatingdepending on the site environment.

FIGURE 10.3.-5. Tamrock service containers include tools and acces-sories to meet equipment service and maintenance requirements.

complete the maintenance. During this time it is good to audit the machine to identify anyneeds for corrective maintenance. For the periodic maintenance, Tamrock has prepared spareparts kits including all parts needed to do service according to instructions. The kits makeboth order and shipment handling easier and faster.

It is important to keep track of what maintenance was performed and what spare parts wereused on each machine. This provides the platform for machine life time control and opera-tional costs follow-up.

SPARE PARTS LOGISTICS

The objective of spare parts logistics is to keep frequently used parts and some critical partson hand at the site, and infrequently used parts supplied by the manufacturer with scheduledtransportation.

Tamrockís Inventory Control Principle (ICP) allows spare parts to be stocked and inventorycontrolled based on classification of what parts are most frequently used at the site. It iscontinuously followed up through the project or operation.

To start ICP, Tamrock makes on-site spare parts recommendations. The recommendations arebased on estimated drilled meters or engine hours. Site conditions are taken into considera-tion as much as possible.

FIGURE 10.3.-4. Spare part inventories at the site can be optimized through TAMROCK ICP.


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cal spare components are stocked on-site and the periodic maintenance is done locally. The components are exchanged as required and sent to the nearest Tamrock Center. The com-ponents are then rebuilt and tested to manufacturer standards by qualified technicians andgenuine parts. The components are returned to the site complete with warranty coverage. The contract may also include the labor for actual component changes.

PERIODIC MAINTENANCE CONTRACT

Preventative periodic maintenance ensures that the equipment can produce according to theproduction schedule and that any downtime is minimized.In this contract, Tamrock personnel make scheduled site visits based on equipment usage.They perform the periodic maintenance according to the recommendations and instructionsgiven in the equipment service manuals. The equipment systems are adjusted to match localneeds. Tamrock supplies the service parts required for each scheduled visit. The charges arefixed regardless of actual labor hours. A detailed report and recommendations for any correc-tive maintenance are presented to the customer. The contract can also cover lubricant supplyand emergency call-out service.

FIGURE 10.3.-7. Main drilling and loading equipment components are typically included in component exchange contracts.

In the workshop or service container, instructions, spare part manuals and product wallcharts are easily available to secure fast checking of required information.

TAMROCK SERVICE AND REBUILDING CONTRACTS

To optimize organizations on site, Tamrock offers different types of service contracts. Somemachine applications are technically advanced and through these service contracts end userscan avoid having trained and specialized skills required for maintaining newer equipmenttechnology. Typically, contracts are tailor-made to match local conditions and needs.Main contract alternatives are:

PARTS SUPPLY CONTRACT

This contract secures spare parts availability, delivery and costs required to keep the equip-ment running. There is usually an optimum parts inventory on site, with a present minimumreordering level and established price structure. Customs and import clearance is organizedand the transportation arrangements are secured. For emergency deliveries, parts can be dropshipped direct from Tamrockís regional locations or plants. This contract can alsoinclude a software package for parts inquiries and ordering, and for inventory control andoperational costs collection.

COMPONENT EXCHANGE CONTRACT

Decreasing downtime, optimizing unit operations and controlling costs are some of the bene-fits of the Tamrock exchange components contract. In a component exchange contract, criti-

FIGURE 10.3.-6. Parts supply contracts ensure the availability of high-qualityoriginal and service parts.


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Full-service contract

A full-service contract offers complete equipment support from Tamrock throughout theprocess. This type of contract secures “peace of mind”.It includes total equipment maintenance and repair by a full-time experienced Tamrock service organization including:

- Mechanics, servicemen, warehousemen, clerks and service managers

- Workshop containers, parts containers, tools, service and maintenance vehicles

- Computer with specialized software: monitoring costs, inventory and maintenance

- Preventative maintenance and component exchange programs are set and followed

- Complete control over site inventory of parts and components:levels, reordering and issuing.

- Drill steel and bit servicing can be included as well

FIGURE 10.3.-9. Example ofhow TAMROCK supervisors supportthe site organization.

SUPERVISION CONTRACT

A supervision contract ensures that the customer´s hands-on personnel are properly focusedand perform exactly what is needed on the equipment. This generally is for a project-typeconstruction where Tamrock has experienced factory trained personnel working daily with thecustomer organization

The supervisors ensure that maintenance programs are properly set and followed. They oftenwork hands-on with site personnel for equipment servicing and repairs, thus provide continu-os training. This contract could consist of parts inventory control and monitoring equipmentoperational costs with specialized software.

FIGURE 10.3.-8. Periodic maintanance.


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FIGURE 10.3.-11. TAMROCK CHA

660 before and after rebuilding.

Rebuilding

To extend economical machine life and secure good availability, it is worth while after cer-tain specified operating hours to do a major machine overhaul or even rebuild the machine.Overhauling or rebuilding provides a good opportunity to upgrade the machine using Tamrockretro-fitting and upgrading packages, which include the latest components and subassemblieswith all required accessories for smooth installation. Tamrock can offer on-site overhauling orrebuilding or at certified rebuilding centers, where specialized and dedicated techniciansguarantee high-quality work.

There are many elements that should be considered and planned for construction site man-agement. The high utilization and availability of the selected equipment is crucial for thesuccess of a project. And it can be achieved through proper service support.

FIGURE 10.3.-10. In full-service contracts, TAMROCK joins resources with the site organization for total performance.

REFERENCES

1. Dowding C. H., Blast vibration monitoring and control, Prentice – Hall Inc., Englewood Cliffs, NJ. 07632, 1985.

2. Oy Forcit Ab, Explosives, Hanko 1987.3. Gustafsson R., Blasting technique, Dynamit Nobel Wien, 1981. 4. ICI, Blasting Practice, Second edition, Birmingham 1956.5. Langefors U., Kihlström B., The modern technique of rock blasting. Almqvist & Wiksells,

Uppsala 1967.6. Olofsson S. O., Applied explosives technology for construction and mining, Ärla 1988. 7. Persson P.-A., Holmberg R., Lee J., Rock blasting and explosives engineering,

CRC Press Inc., 1994.8. Saari K., Large rock caverns, Proveedings of the international symposium Helsinki

25-28 august 1986, volume 2, Pergamon Press 1986. 9. Tamrock Oy Handbook of underground drilling, Second edition, Tampere 1986.10. Tamrock Oy, Surface drilling and blasting, 1995.11. U.S. Department of Transportation, Rock Blasting and Overbreak Control, NHI Course

No. 13211, 1991.12. Vihtavuori Oy, Blasting excplosives – we take you through, Blasting explosives unit,

FIN-41330 Vihtavuori, 1994. 13. Vuolio R., Blast vibration: Threshold values and vibration control,

The Finnish Academy of Technology, 1990. 14. Vuolio R., Räjäytystyöt 1991, Forssa 1991.15. University of Trondheim, Tunneldrift, Ventilasjon, Prosjektrapport 17-91, Trondheim 1991. 16. RIL 154-2. Tunneli- ja kalliorakennus, Espoo 1987. 17. Tamrock Oy, Underground drilling and loading handbook, Tampere 1997.18. Kivialan ammattioppi 2, Kivilohkareiden louhinta, Opetushallitus, Helsinki 1989. 19. TKK IGE-B19, Rakennuskivet ja niiden hyödyntäminen, Espoo 1995.

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