Project Profiles : SSiS

Turnkey Solution Provides Safe Chairlift Access to Mineworkers at Bafokeng Rasimone Platinum Mine

 

Speedy & Versatile Solution for Solving Steep & Deep Chairlift Decline Tunnel Requirements

The North Shaft Chairlift Project allows for the development and installation of a chairlift from surface to 5 level. This will replace the use of the personnel-riding belt to transport people. The project commenced in 2012 and is 35% complete against a plan of 19% and equates to being 592m ahead on the development schedule. The capital expenditure, to date, amounts to R28.44 million, with a final estimated cost of R136 million.

Project Details Time Line Project Team
Structure: Multi-Plate: MP200 Custom 39S Arch Pre-Assembly Start: 1 July 2013 Owner: BRP JV
Geometry: 3.97m span x 3.34m rise x 77.68m long Pre-Assembly Complete: 31 July  2013 Engineer: DRA Mining
Box Cut:  Angle = 16.5°; Pit Depth = 22.0m Assembly Time Actual: 23 Days Contractor: G4 Civils
Max. Cover: = 18.83m Assembly Time Estimated: 14 Days Rigger: CJH Cranes
Purpose: Chairlift for workers Pit Installation Start: 23 September 2013 Portal Design & Supply: SSIS &  AIL    
Design Life: 30 Years Pit Installation Complete: 27 September 2013    

 Project Challenges

Unique site and project requirements necessitated an innovative construction approach by G4 Civils who approached SSIS to use a Multi•Plate system. G4 Civils and SSIS offered a turnkey solution meeting stringent safety requirements while saving significant construction costs and time. Challenges faced included: 1) acute decline angle of 16.5°, 2) unstable side slopes, 3) narrow boxcut with tight side clearance and 4) very short implementation period.

SSIS was able to design and supply the Multi•Plate chairlift decline tunnel meeting all of the above requirements with no compromises. For safety reasons, the portal tunnel was pre-assembled next to the pit and installed on the steep decline by a lift- and-slide procedure. The pre-assembled sections substantially reduced time in the pit and subsequent Health and Safety risks. Factory applied 915 g/m2 galvanized coating of the structure will ensure adequate service life. G4 Civils provided seamless assembly and installation of the tunnel and supporting infrastructure.

 

 

Super-Cor Decline Portal Tunnel for Sasol's Impumelelo Shaft Mine

Remarkable Lift of Entire 50 ton Decline Portal Tunnel for Impumelelo Shaft

Sasol Mining’s new R4.6-billion Impumelelo Shaft at the Twistdraai Colliery, in Mpumalanga, has been under construction since  May 2011. Impumelelo will supply coal to Sasol Synfuels and also export to domestic markets once in operation. Facing great challenges and with amazing engineering ideas, Murray & Roberts Cementation (MRC) began work on the contract which required a men and material shaft, a ventilation shaft and also a decline and coal seam development on the No. 2 and No. 4 seams. Sasol Mining again decided to install a Super-Cor decline portal tunnel which was successfully lifted into position on Thursday, 4 October 2012. This is the second Super-Cor portal tunnel installation for Sasol Mining, the first being the 72.5 m long tunnel at their Thubelisha Shaft.  

Project Details
Time Line  
Project Team  
  Structure:  Super•Cor SC-A6 31S Arch    Pre-Assembly Start:  23 April 2012     Owner: Sasol Mining 
Geometry:  8m span x 4m rise x 19m long   Pre-Assembly Complete:  23 May 2012    Engineer: RSV-ENCO-GOBA JV
Box Cut:   Angle = 17°; Pit Depth = 10.3 m   Assembly Time Actual:  14 Days   Contractor: Murray & Roberts Cementation
Max. Cover:  = 7.06 m    Assembly Time Estimated:  8 Days   Rigger: Sarens Group
Surface Load: 250kPa workshop   Pit Installation Start:  27 September 2012   Portal Design & Supply: SSIS & AIL
Purpose:  Conveyors for coal transport   Pit Installation Complete:  27 Sept  2012    
Design Life:  35 Years        

  Project Challenges

Unique site and project requirements necessitated an innovative construction approach by MRC who approached SSIS to use the revolutionary Super•Cor system. Working closely together with MRC, SSIS was able to offer a solution meeting stringent safety requirements while offering construction cost and time savings. Challenges faced included: 1) acute decline angle of 17°, 2) recently installed conveyor, 3) corrosive environment, 4) heavy workshop load on top of decline tunnel, and 5) ongoing blasting and mining activities.

When site conditions required that the length of the Super•Cor structure be reduced from 22 m to 19 m, SSIS quickly reviewed the structure and bolting layout. The structure was then suitably shortened without the need to drill extra holes or to cut any plates.

SSIS / AIL was able to design and supply the Super•Cor portal tunnel meeting all of the requirements for the heavy conveyor workshop. The entire 19 m long portal tunnel was pre-assembled next to the pit and installed in the 17° decline using a 550 ton Sarens crane with a pre-angled spreader beam. The entire lifting procedure substantially reduced the time spent in the pit ensuring that health and safety risks were reduced while also dealing with the live mining activities.

 

Super-Cor Decline Portal Tunnel for Sasol's Shondoni Shaft Mine

  

SSIS Supplies a 3rd Decline Tunnel for Sasol Mining at their Shondoni Mine Development

Sasol Mining’s new Shondoni Colliery in Mpumalanga, South Africa, started construction in April 2012. It is a replacement of Middelbult Colliery with a brownfields interface underground. The new mine will replace the Main, Ventilation and Decline shafts. First coal from the new complex is expected to be delivered in 2015. Shondoni will supply coal to Sasol Synfuels.

 

Project Details Time Line Project Team
  Structure:  Super•Cor: Type SCA-31 S Arch   Pre-Assembly Start:  1 July 2013 Owner: Sasol Mining
Geometry:  8.07 m span x 4.04 m rise x 72.55 m long Pre-Assembly Complete:  22 July  2013 Engineer: Worley Parsons
Box Cut:   Angle = 12°; Pit Depth = 18.5 m Assembly Time Actual:  22 Days Contractor: Aveng Mining Shafts& Underground
Max. Cover:  = 14 m Assembly Time Estimated:  17 Days Rigger: Johnson Crane Hire
Purpose:  Conveyors for coal transport Pit Installation Start:  15 August 2013 Portal Design & Supply: SSIS & AIL
Design Life:  30 Year Pit Installation Complete:  19 August 2013    

 

Project Challenges

Unique site and project requirements necessitated an innovative construction approach by the Contractor who approached SSIS to use the revolutionary Super•Cor® system. Working closely together SSIS was able to offer a solution meeting stringent safety requirements while saving significant construction costs and time. Challenges faced included: 1) Deep and wide boxcut excavations, 2) strict construction deadline, 3) corrosive environment, 4) lack of available engineered backfill material and 5) overfilling of the pit with extra berm material.

 

Super-Cor Decline Portal Tunnel for Sasol's Thubelisha Shaft Mine

 

Speedy & Versatile Solution for Solving Live Conveyor & Steep Decline Portal Tunnel Requirements

Sasol Mining’s new R3.5-billion Thubelisha Shaft at the Twistdraai colliery, in Mpumalanga, was opened in May 2012. The current Twistdraai colliery shaft system had reached its economic limit and required relocation of the shafts to the Thubelisha site, which will extend the life of the Twistdraai colliery beyond 2039. Thubelisha will supply coal to Sasol Synfuels and the export and domestic markets.

 

Project Details - Decline Portal Tunnel      Time Line      Project Team
   Structure:  Super•Cor: Type SCA-31 S Arch          Pre-Assembly Start:  24 May 2011          Owner: Sasol Mining
   Geometry:  8.0 m span x 4.02 m rise x 72.55 m long         Pre-Assembly Complete:  23 June  2011        Engineer: RSV-ENCO-GOBA JV
   Box Cut:   Angle = 17°; Pit Depth = 21.3 m        Assembly Time Actual:  17 Days        Contractor: Stefanutti Stocks Civils
Max. Cover:  = 16.7 m        Assembly Time Estimated:  14 Days        Rigger: Vanguard
Purpose:  Conveyors for coal transport        Pit Installation Start:  29 June 2011        Portal Design & Supply: SSIS & AIL
Design Life:  30 Year        Pit Installation Complete:  4 July 2011         

 

Project Challenges

Unique site and project requirements necessitated an innovative construction approach by the Contractor who approached SSIS to use the revolutionary Super•Cor system. Working closely together SSIS was able to offer a solution meeting stringent safety requirements while saving significant construction costs and time. Challenges faced included: 1) acute decline angle of 17°, 2) live conveyor, 3) corrosive environment, 4) lack of available engineered backfill material and 5) overfilling of the pit with extra berm material.

SSIS was able to design and supply the Super•Cor portal tunnel meeting all of the above requirements with no compromises. For safety reasons, the portal tunnel was pre-assembled next to the pit and installed on the steep decline by a lift- and-slide procedure (world-first). The pre-assembled sections substantially reduced time in the pit and subsequent Health and Safety risks while also dealing with the live conveyor. Specially applied LiquidRubber™ corrosion coatings, in addition to the 915 g/m2 galvanized coating of the structure, will ensure adequate protection against the harsh environment.

SSIS was further able to test and approve freely available coarse-ash material from Sasol’s plant in Secunda for use as engineered backfill material around the structure due to the general lack of available and approved material. Special triaxial & hydrostatic compression tests were conducted together with sieve analyses, compaction tests and Slake Durability tests.

Lastly, when it was required to increase the loading on the structure during the design phase (to get rid of stockpiled berm material), SSIS analysed the structure to confirm its ability to handle the extra loading using advanced finite element analysis (FEA) taking proper account of soil-structure-interaction principles. The structure was suitably modified by specifying thicker plates where needed and employing the unique double barrel plate configuration at the deepest section of almost 17 m.

 

 

 

 

 

 

 

 

 

 

 

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