Basics of Rock SupportRev. April 2008 Why reinforcing the rock? Reinforcing the rock is usually seen as: Time consuming. Non directly productive. Expensive. Complicated. So why reinforcing the rock ? Human workforce SAFETY. Secure the access to the orebody. Sandvik Mining and Construction How? Rock & cable bolting. Meshing. Shotcreting (sprayed concrete). Timber support. Steel Arches, concrete lining: Used in special conditions, I.e. production level development for block caving Backfilling. We won’t go further on those 4 because they’re not part of current SMC UGHRM offering. Sandvik Mining and Construction Rock Support To create a compressive stress arc around the opening Helps the rock to support itself To support the loose blocks Prevents the loose blocks of falling out and prevents the progression of cave-in Compression stress field in tunnel roof created with fully grouted bolts. Sandvik Mining and Construction . RMR-Bienawski / Relationship stan up time Sandvik Mining and Construction . RMR-Bienawski Determination of support using Sandvik Mining and Construction . FULLY-EMBEDDED BOLTS Either resin or cement grouted FRICTION BOLTS Split Set® or Swellex® Sandvik Mining and Construction .Bolt types ANCHOR-POINT BOLTS Commonly known as «expansion shell» bolts or wedge type. Friction bolts Immediate support Full column anchor Sandvik Mining and Construction . The bolt is acting as a standard mechanical split pin and stabilize the rock masses by creating compressive stress.Split set bolt Drill a hole smaller than the outside diameter of the bolt: The drilling bit size is critical. Request an impactor or a rockdrill on the bolting line. Split set bolt 2 of the most common split set bolt: Sandvik Mining and Construction . but the friction is created by inflating the bolt with high pressurized water. Friction bolts Immediate support Full column anchor Sandvik Mining and Construction .Swellex bolt This bolt is acting like a split set. Swellex -DIAGRAM – 0 Bar 150 Bars 15 Bars 300 No leak DRAIN SEALING SEALING FILLING + + INFLATION SEALING Sandvik Mining and Construction . Swellex bolt Some of the most common swellex bolts Swellex Swellex Mn12 Swellex Mn16 Swellex Mn24 Breaking load 120 kN 160 kN 240 kN Hole diameter 32 – 39 mm 43 – 52 mm 43 – 52 mm Sandvik Mining and Construction . Grouted bolt Resin grouted (immediate support and can be pre-tensionned). simple steel rebar cement or resin fill Sandvik Mining and Construction . Cement grouted (no immediate support): Cable bolting replace the rebar by a steel strand. Grouted cable bolt Used to bind and secure large rock masses Used both before and after excavation: Sublevel stoping: To prevent cave-in from hanging wall & to support pillars Cut and fill stoping: To reinforce the roof (mostly overhand cut and fill) Room and Pillar: To reinforce the roof and the pillars Block caving: To reinforce the drawbell.and production area for safer operation and extended drawpoint lifetime Drifting (long bolts within limited space) Cable used: .15. or .Often 2 strands / hole Sandvik Mining and Construction .15.2 mm steel strand.Breaking strength 25 tonnes .2 mm bulb anchor . Immediate support.Point Anchor bolt Mechanical bolts. Can be cement-grouted: Wedge type cement grouted = Kiruna Bolt expansion shell Sandvik Mining and Construction wedge type . Other types Combination: CT bolt Immediate support + fully grouted + corrosion protected Sandvik Mining and Construction . fairly low cost Fast installation. Availability of resin may be problem. immediate support Good properties. Immediate support Immediate support Fast installation. immediate support. expensive Expansion shell Cement grouted wedge-type Swellex Split-set (or copy of) CT-bolt 1.Lifespan & cost Properties of different bolt types Bolt type Cement grouted rebar Resin grouted rebar Lifespan Permanent Permanent (when fully grouted) Temporary / Permanent when grouted Temporary / Permanent when grouted Temporary (longer than split-set) Temporary Permanent Relative cost 1 2 General comments Low cost. good availability.5 1. immediate support Fast installation.25 3 1 4 Sandvik Mining and Construction . No immediate support Reasonable cost. Can be installed mechanized with screen manipulator on Robolt.Meshing Used together with bolting (and shotcrete) Does not prevent deformations. Can stand up large deformations without breaking. Screen the size of loose rocks that might fall. but prevents loose rock from falling. Sandvik Mining and Construction . How to choose a bolter Rev. April 2008 . DS510 DS310 Robolt 5 Cable bolt: DS420. DS410.How to choose a bolting unit? Rock bolts: DS310. DS520 DS410 Robolt 7 DS420 Cabolt 7 Sandvik Mining and Construction . the same bolting head shall be proposed to the customer. BH TUC Sandvik Mining and Construction . As far as possible. The bolting heads are so different that it is really hard to get used to the other type once trained used to one kind. TUC from Lyon.How to choose a bolting unit? What type of bolting head does the customer is already using ? BH from Tampere. DS310/DS410 Sandvik Mining and Construction .How to choose a bolting unit? What is or are the average drift height to be bolted? What is the bolt length to be installed? Check first B value: The drift height should be < B. and as close possible to utilize the bolter at his maximum output. manoeuvrability is critical in operation.How to choose a bolting unit? Check then A value: Don’t hesitate to add a safety margin when possible. Sandvik Mining and Construction . or really high spot bolting. Sandvik Mining and Construction .How to choose a bolting unit? C is the maximum reachable height and is usually used for bolting over blasted or excavated areas. C value is usually not be considered as normal bolting height. 6m 7 x 6m 8 x 6.9m ZRU 1407 12 x 9m 12. Drift (8' bolt) 7 x 6.2m 8.2m 13 x 10.8m Max.7 x 9.How to choose a bolting unit? Boom DS310 DS310 DS410 DS510 B26B B26BXL ZRU 707 Basic WxH Roughly (8' bolt) 6 x 5m 7 x 6m 8 x 7m 6 x 5.5m 8 x 7.9 x 7.6m Sandvik Mining and Construction . How to choose a bolting unit? Need for a second optional boom? Basket boom => DS410. Screening (meshing) boom : Better to propose that option on separate boom for manoeuvrability: • Available from DS410 classe size Sandvik Mining and Construction . or DS510. it is better to offer DS310 (Robolt5) even if the DS410 (Robolt 7) could fit the application. … Sandvik Mining and Construction . The benefit will be carrier spare parts communality. less operator training.How to choose a bolting unit? Fleet effect: If the customer owns a large fleet of DD310 (Axera 5). Resin cartridges OD and length. Bolt diameter. Plate sizes.Mandatory informations Bolt type. Bolt length. Sandvik Mining and Construction . Working with HLX1 & RHR 50. Sandvik Mining and Construction . TU LP & LPM: Available on LP bolters DS210L (M) and only for Expandable shell and resin bolts.ppt Available on DS310 and DS410 Working H 200. DS510 Working with HL300 or HL 510. HH200.Bolting heads TUC:How Does it Work. Video TULP & TULPM. RHR 50. BH: Available on DS410. Bolting booms Bolting booms B26 B & XLB: DS310 ZRU 707: DS410 ZRU 1407: DS510 Sandvik Mining and Construction . DS510 Sandvik Mining and Construction . Available & standard on DS410.Bolting controls THC 560C: Fully hydraulic controls based on standard THC 560 face drilling controls. Available & standard on DS310 TPC 301 EW: Electric controls based on a PLC unit. DS510 On the drilling boom on DS310 Sandvik Mining and Construction .pdf Videos Spec sheet Available on: As a separate boom DS410.Screen handler Screen Handler. DS510.Bulk cement system Video Bulk cement system available on: DS410. Standard on DS420 Sandvik Mining and Construction . DS310 (Robolt 5) Small cross sections Compact size (5 size class) Max reach 7.0 m Screen handler option Spec sheet Sandvik Mining and Construction .3 m Bolt length up to 3. 9 m Bolt length up to 3.0 m Screen handler option Basket boom option Spec sheet Sandvik Mining and Construction .DS410 (Robolt 7) Small to medium cross sections Max reach 7. 4 m Bolt lengths up to 6.DS510 (Robolt 8) For medium.0 m Basket boom option Sandvik Mining and Construction .to large cross sections Max reach 12. DS110L / DS210L (Robolt LP & XLP) DS210L XLP DS110L Video Sandvik Mining and Construction . Cable bolting .Cabolt Fully mechanized working cycle Drilling Grouting Cable installation Cabolt 7 Spec sheet Sandvik Mining and Construction . Tools Sandvik Mining and Construction .Rock bolting .