Post on 29-Mar-2015
transcript
THORNEGROUP
Earthworks : Recycling : Reclamation : Demolition : Dismantling
THORESBY LAKE PHASE 1
PRE-SUBSIDENCE WORKS
Client: UK COAL Consultant: Black & Veatch
THORNEGROUP
THORESBY LAKE PHASE 1
Project Overview
Earthworks : Recycling : Reclamation : Demolition : Dismantling
Thorne were appointed Principal Contractor for the Thoresby Lake Phase 1 project which was undertaken within the tranquil settings of Thoresby Estate.
The subsidence would lead to the lake bursting its banks and by-passing the man-made dam at the Eastern end.
The Client, UK COAL, intended to open new coal workings beneath the lake which would subsequently be affected by up to 900mm of subsidence.
The aim of the project was to raise and reprofile the Northern and Southern shores of the lake prior to the subsidence occurring.
Located within the historic Thoresby Estate and a Grade 1 listed deer park, the site was under the close scrutiny of the Estate Trustees, English Heritage, English Nature, the Environment Agency & Hotel (located within Thoresby Hall) and was also designated as a SSSI.
Close consultation between the interested parties and sympathetic project management were required to achieve a swift and efficient completion to the works on behalf of the Client.
Enabling Works
South Shore
North Shore
Project Summary
THORNEGROUP
THORESBY LAKE PHASE 1
Earthworks : Recycling : Reclamation : Demolition : Dismantling
Project Overview
The project consisted of 3 elements:
1, Enabling works to allow construction access
2, South shore works – realignment, raising and bank reinforcement
3, North shore works – realignment, raising and natural habitat creation
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Enabling Works
South Shore
North Shore
Project Summary
THORNEGROUP
THORESBY LAKE PHASE 1
Earthworks : Recycling : Reclamation : Demolition : Dismantling
Site entrance set up & 400m track installed to compound location
South Shore
Project Overview
Enabling Works
North Shore
Project Summary
THORNEGROUP
THORESBY LAKE PHASE 1
Earthworks : Recycling : Reclamation : Demolition : Dismantling
Access to the Northern shore and Lake Outfall 1 installed
South Shore
Project Overview
Enabling Works
North Shore
Project Summary
THORNEGROUP
THORESBY LAKE PHASE 1
Earthworks : Recycling : Reclamation : Demolition : Dismantling
Temporary bridge, including foundations installed for access to the dam
A 24m, 45t rated, construction bridge, requiring a 100t crane for installation
South Shore
Project Overview
Enabling Works
North Shore
Project Summary
THORNEGROUP
THORESBY LAKE PHASE 1
Earthworks : Recycling : Reclamation : Demolition : Dismantling
Access track constructed on the dam
South Shore
Project Overview
Enabling Works
North Shore
Project Summary
THORNEGROUP
THORESBY LAKE PHASE 1
Earthworks : Recycling : Reclamation : Demolition : Dismantling
2nd Temporary bridge installed for access across lake outfall 2
A 13m, 45t rated, construction bridge, requiring a 100t crane for installation
South Shore
Project Overview
Enabling Works
North Shore
Project Summary
THORNEGROUP
THORESBY LAKE PHASE 1
South Shore
Earthworks : Recycling : Reclamation : Demolition : Dismantling
Project Overview
Enabling Works
Access from bridge to South shore working area installed
Safety fencing and site signage installed
North Shore
Project Summary
THORNEGROUP
THORESBY LAKE PHASE 1
South Shore
North Shore
Project Summary
Earthworks : Recycling : Reclamation : Demolition : Dismantling
Project Overview
Enabling Works
South Shore: Site Clearance
Approximately 20 trees professionally felled
Listed Monument removed for renovation
Topsoil stripped prior to realignment
THORNEGROUP
THORESBY LAKE PHASE 1
South Shore
North Shore
Project Summary
Earthworks : Recycling : Reclamation : Demolition : Dismantling
Project Overview
Enabling Works
South Shore: Realignment
Chainage 0 to 160 m
Bank cut to 1:6 gradient
Cut transported to fill area
Erosion protection placed
Topsoil reinstated
THORNEGROUP
THORESBY LAKE PHASE 1
South Shore
North Shore
Project Summary
Earthworks : Recycling : Reclamation : Demolition : Dismantling
Project Overview
Enabling Works
South Shore: Realignment
Chainage 160 to 400 m
New bank alignment cut
Bank cut to 1:2.5 gradient
Cut placed in fill areas and banks raised
Profile for armourstone installation cut
THORNEGROUP
THORESBY LAKE PHASE 1
South Shore
North Shore
Project Summary
Earthworks : Recycling : Reclamation : Demolition : Dismantling
Project Overview
Enabling Works
South Shore: Realignment
Chainage 160 to 400 m
New island and channel formed
Sub-armourstone geotextile installed
Armourstone erosion protection installed
Island topsoil applied
Topsoil reinstated and seeded
Accesses tidied and temporary crossings removed
THORNEGROUP
THORESBY LAKE PHASE 1
South Shore
North Shore
Project Summary
Earthworks : Recycling : Reclamation : Demolition : Dismantling
Project Overview
Enabling Works
North Shore: Site Clearance
~ 100 trees professionally felled
15,000 m2 of vegetation cleared
3,500 m2 of topsoil stripped
Reeds and bulrushes transplanted
THORNEGROUP
THORESBY LAKE PHASE 1
South Shore
North Shore
Project Summary
Earthworks : Recycling : Reclamation : Demolition : Dismantling
Project Overview
Enabling Works
North Shore: Realignment
Colliery shale front line bank removed
Small flooding protection bank left in situ
Lake bed formed behind original bank
New shoreline bund formed
THORNEGROUP
THORESBY LAKE PHASE 1
South Shore
North Shore
Project Summary
Earthworks : Recycling : Reclamation : Demolition : Dismantling
Project Overview
Enabling Works
North Shore: Finishing Works
Natural habitats created
Boat launch excavated and shuttered
Boat launch cast and married-in to bund
Flooding protection bank removed
THORNEGROUP
THORESBY LAKE PHASE 1
South Shore
North Shore
Project Summary
Earthworks : Recycling : Reclamation : Demolition : Dismantling
Project Overview
Enabling Works
Project Summary: The Finished Product
South Shore: Water level raised, pre-subsidence
THORNEGROUP
THORESBY LAKE PHASE 1
South Shore
North Shore
Project Summary
Earthworks : Recycling : Reclamation : Demolition : Dismantling
Project Overview
Enabling Works
Project Summary: The Finished Product
North Shore: Water level raised, post-subsidence
THORNEGROUP
THORESBY LAKE PHASE 1
South Shore
North Shore
Project Summary
Earthworks : Recycling : Reclamation : Demolition : Dismantling
Project Overview
Enabling Works
Project Summary: Analysis
A score of ZERO Heath & Safety incidents recorded
A score of ZERO Environmental incidents recorded
A Considerate Constructors Scheme score of 32.75 achieved
A post-completion Client satisfaction survey score of 98%
Works completed in advance of the of the mining subsidence
Works completed 2 weeks AHEAD of the 17 week programme
Final cost of the works to the Client at 4% UNDER BUDGET