Construction Methodology
CONSTRUCTION METHODOLOGY
KŌPŪ MARINE PROJECT
November 2021
Document Quality Statement
Report prepared by: Urban Solutions Project Limited Report Number: US-B325-100
Distribution: Thames-Coromandel District Council Prepared for: Sam Edlin
Project Manager
Thames-Coromandel District Council
Document Author: Kirsten Dovey
Senior Project Manager
Reviewed by: Lorenzo Canal Project Director Authorised for
issue: Lorenzo Canal
Director
Document Control
The following person(s) shall receive a copy of this document upon each subsequent release:
Name Title/Group Organisation
Sam Edlin Project Manager Thames-Coromandel District Council
Revision History
The following table outlines the revision history of this document:
Version Publication date Comments
Version 1 July 2021 For Consent
Version 2 November 2021 For Consent (redesign)
Limitations
This report has been prepared exclusively for Thames Coromandel District Council with respect to the specific brief given to us. Information, opinions, and recommendations contained in it cannot be used for any other purpose or by any other entity without our review and written consent. Urban Solutions accepts no liability or responsibility whatsoever for or in respect of any use or reliance upon this report by any third party.
Contents
1.0 Purpose ...4
2.0 Introduction ...4
3.0 Works Staging...5
3.1 Earthworks & Roading Contract - Separable Portion 1...5
3.1.1 Management Plans...5
3.1.2 Site Establishment ...5
3.1.2 Demolition and Earthworks...5
3.1.3 Mangrove trimming...6
3.1.4 Drainage works...6
3.1.5 Swale...6
3.1.6 Utility Supply – Water...6
3.1.7 Utility Supply – Power and Communications...6
3.1.8 Pavement and Roading – King St and Quay St...7
3.1.9 Pavement and Roading – Commercial/Parking Area...7
3.1.10 Lighting and Security ...8
3.2 Marine Structures Contract ...8
3.2.1 Commercial Slipway...9
3.2.2 Commercial Wharf and Floating Pontoon ...10
3.2.2.1 Landward Operations ...10
3.2.2.2 Seaward Operations...11
3.2.3 Rock Revetment...13
3.3 Earthworks & Roading Contract - Separable Portion 2...14
3.3.1 Pavement and Roading – Commercial/Parking area ...14
3.3.2 Landscaping, Planting, and Signage...14
3.3.3 Reinstatement ...14
1.0 Purpose
The purpose of this document is to outline the construction methodology and staging of works to deliver the Kōpū Marine project.
2.0Introduction
The Kōpū Marine Project involves the delivery of marine servicing infrastructure at the Kōpū Industrial precinct located on the Waihou River, 7km south of Thames township. The works generally involve the following:
- New commercial wharf with a floating pontoon
- New commercial slipway and upgrade commercial area - Formation of King Street & upgrade to Quay Street
The physical works has been separated into an Earthworks and Roading Contract and a Marine Contract.
This Earthworks and Roading Contract includes:
i. Commercial Area
The commercial area is approximately 8,900m² and is unsealed. The works involve a section of the existing silt trap area being filled and the commercial haulage area topped with metal and regraded to improve access and vehicular movements.
ii. King Street Formation & Quay Street Upgrade
Access to the new public boat ramp will be provided by forming King Street. King Street will have a two-lane carriageway with an overall width of 8.0m and an asphalt pavement surface.
The new footpath adjacent to the properties to the north will have a combined services trench with power and wastewater and associated street lighting. A vegetative swale along the southern side of the road will capture and treat stormwater runoff.
Quay Street is to be widened to 10m over the existing stop bank to allow access for vessels to be hauled out of the slipway to adjacent marine sector businesses and beyond.
The Marine Structures Contract includes:
i. Commercial Wharf and Floating Pontoon
The proposed 100m long commercial wharf will consist of a fixed piled wharf structure with a T shaped wharf head and floating concrete pontoon. The commercial wharf / pontoon provides a berth for in-water servicing. The heavy-duty floating pontoons will be accessed by a gangway.
ii. Commercial Slipway
A new reinforced concrete slipway with fender piles and a pedestrian access gangway to aid boat handing, is to be constructed adjacent to the existing slipway. The new concrete slipway will improve commercial haulage capabilities and will be located adjacent to the existing slipway to ensure commercial operations can continue during the construction period. The slipway is to be constructed using a temporary sheet piled coffer dam.
3.0Works Staging
The Earthworks and Roading Contract will commence first and has been split into two stages to accommodate the marine structures construction and allow for ground settlement.
Stage 1 generally includes the formation of King Street then stripping vegetation, bulk earthworks, and culvert installation prior to handing the site over to the Marine Contractor.
Following handover, the marine contractor will exclusively occupy the site, mobilise machinery and plant using the King Street access and utilise the newly formed carpark.
Upon completion of the marine structures, the earthworks and roading contract will re-mobilise for Stage 2 works to complete trimming, levelling and pavement works, planted swale and bank stabilisation, along with the culvert at the entrance to Quay Street.
Below is a detailed breakdown of the staging and construction methodology provided by the contractors who will be undertaking the works.
3.1 Earthworks & Roading Contract - Separable Portion 1 3.1.1 Management Plans
Preparation of management plans including Site Specific Safety, environmental, traffic, quality assurance, construction management.
Ecological assessment prior to construction will be undertaken to allow for construction works to be undertaken during the bird nesting season.
3.1.2 Site Establishment
The construction site will be established - surveyed, setout, fences erected, and environmental controls installed.
3.1.2 Demolition and Earthworks
Timber posts, wire fences, and timber gates will be removed and disposed of. A digger will remove the vegetation, then will strip the topsoil and any undercuts that are required. Any large vegetation removed will be mulched and utilized as ground stabilizing cover if deemed suitable. There is also the option to use the waste material as landscaping mulch. Surplus material will be disposed of off-site.
8-10m long timber gum piles will be installed within the existing silt trap. Following this, the bulk fill operation and any subgrade improvement works will be undertaken. Cut to fill conditioning/drying will be completed by a conventional disking/turning operation. Additional equipment such as bulldozers and rollers will be utilized during this operation.
Clearing of the hardstand and road alignment of King Street will then take place using an excavator and truck operation. All waste material will be transported to an authorised tip site.
Removal of the existing stormwater culvert will be completed prior to installation and back fill of the new units and will occur concurrently to other removal operations.
3.1.3 Mangrove trimming
Where vegetation trimming is specified, mangroves will be trimmed using hand tools only, following the best practice for removal outlined in the Guidelines for Managing Mangrove (Mānawa) Expansion in New Zealand.
In order to decrease the adverse effect on the environment mature mangroves will be cut to a maximum height of 20mm above the estuary bed.
3.1.4 Drainage works
After removal of the existing culverts, lines and levels will be marked out for the new units.
Installation and drainage will be completed to manufactures and Council specified bedding and back fill detail. Placement and compaction of the back fill material will be done in 200- 300mm lifts, with levels confirmed through Scala or Clegg hammer testing, dependent on back-fill material. Cirtex X40/40 is to be installed above the first lift of imported fill.
All pipe installations will have the entry and exit inserts surveyed to confirm compliance with the design.
3.1.5 Swale
The swale drain will be excavated upon completion of the bulk fill operation. The excavator and truck operation will bulk out the subgrade cut, then complete the subsoil excavation and installation as per the design. Following this, final trimming of the subgrade will be completed.
Levels will be confirmed with a topographical survey after topsoil placement.
3.1.6 Utility Supply – Water
Installation of the water supply down King Street and across the hardstand area will occur after the placement of bulk fill material in the hardstand area and prior to placement of the GAP 40 aggregate along King Street. Valve and Tee locations will be clearly marked to ensure protection from construction traffic during the remaining works period. As the water line is installed, on-site survey resources will record pipe alignment for as built drawings and design confirmation purposes.
3.1.7 Utility Supply – Power and Communications
Cabling will be trenched in with the installation of the other services where applicable. Outside of this, locations will be excavated to the design depth and installed with the appropriate bedding and cover material. A Power and Communications duct is to be installed including thrusting under existing stopbank. The alignment of cables will be surveyed for as built purposes.
3.1.8 Pavement and Roading – King St and Quay St.
Subbase: Where geotextile or grid is required, material will be tested prior to placement, and the level and extent will be surveyed for as built purposes. Pavement construction will commence following the approval of subgrade testing.
Aggregate will be spread directly onto the pavement surface using a truck and trailer approach. The depth of the aggregate will be controlled by a Total Station machine-controlled grader.
A 10-14T single drum vibrating roller, static roller and watercart will be used to compact the aggregate while at optimum moisture content, and to specified densities ad tolerances.
Quality management of the sub basecourse material will be in line with the parameters outlined on the Roading Inspection and Testing Plan (ITP). As sections are completed, the quality assurance (QA) information will be submitted to the Engineers Representative for approval prior to proceeding with kerb and channel works.
Kerb and Channel: The kerbing will be set out using Total Station survey equipment. Prior to kerb lines being poured, kerb ‘strings’ will be placed in their correct alignment to help guide the kerbing machine. Kerbing will then be backed up by either fill material, aggregate, or topsoil, dependent on the location and scheduled behind-kerb treatment prior to basecourse placement. This provides support to the new kerbing and helps to avoid movement during subsequent pavement construction activities.
Kerbing will be slip-form constructed wherever possible to provide a uniform and consistent finish.
Basecourse: Construction will follow the cured kerbing and approval of subbase QA. The TNZ M4 AP40 aggregate will be placed and spread using the same process as the subbase material.
Compaction will also be completed using the same process and equipment, along with a PTR roller. Quality management of the basecourse will also be recorded on the ITP, and the QA submitted to the Engineer’s Representative for approval prior to proceeding with surfacing works.
3.1.9 Pavement and Roading – Commercial/Parking Area
For the commercial and parking areas, aggregate and bulk fill material will be supplied to site with truck and trailer units. The construction team will spread the material from the boat ramp area and work towards the north-western extent of the site. A bulldozer will be used to push the material to required layer thickness, following with a 14T padfoot roller and 14T single drum vibrating roller to compact the fill. Layers will be trimmed off with a Total Station grader that will also confirm alignment and level. This layer will then be subject to quality assurance testing, including a surface level survey.
Compaction and dust control for the bulk fill operations will be supported by a 10,000L watercart.
Separable portion 1 of the Earthworks and Roading Contract will be considered complete after the placement and compaction of the GAP65 aggregate to a depth of 300mm – allowing adequate access for the marine works to take place.
3.1.10 Lighting and Security
Cabling will be trenched in with the installation of the other services where applicable. Outside of this, locations will be excavated to the design depth and installed with the appropriate bedding and cover material. The alignment of cables will be surveyed for as built purposes.
Installation of the light poles will take place following cable location and basecourse aggregate placement. The ground planted poles will have the holes drilled and poles placed with checks for alignment and level during the back fill process.
Upon completion of Separable Portion 1 – The civil contractor will vacate and hand over the site to the marine contractor.
3.2 Marine Structures Contract
The overall strategy to deliver the Marine Contract is outlined below:
- Commence construction of the commercial wharf from the landside using an oversized crawler crane;
- Install sheet piles to the commercial slipway;
- The remaining portion of the commercial wharf will then commence outwards from the last bent installed from land and become a self-supporting workface whilst the crawler crane on land aids the Commercial Slip way construction;
- Rock revetment works will be the last section of work to commence.
3.2.1 Commercial Slipway
1. Create the landside working platform for crane within suitable working radius of the distal end of sheet pile cofferdam. (Roughly 100m²)
2. Install temporary CHS piles to the cofferdam perimeter.
3. Install main frame members and crossheads to allow driving of steel piles.
4. Install sheet piles sequentially working from the two corners of the cofferdam back towards land.
5. Strip frame back and run sheet piles back towards the landward side of the cofferdam.
6. Pump dry with two high-head water pumps simultaneously. Pumps are to be kept on site with one on standby to ensure redundancy on site immediately to minimise disruption to the works.
7. Cut and dispose 300mm surface layer of sediment. The lower half of the ramp will be cut to subbase depth.
8. Supply, place and compact 500mm bulk fill and bulk sleeves.
9. Supply, place and compact 300mm GAP 65 basecourse.
10. Prefabricated sections of reinforcing will be lifted into place, placed on chairs, and tied together. Following engineering preapproval, the commercial slipway will be poured.
11. Remove cofferdam. The cofferdam will be removed with a crane sitting on the newly poured commercial slipway.
12. Install steel and PE sleeved piles for commercial slipway catwalk. The piles for the slipway catwalk will be driven and filled.
13. Deliver aluminium catwalk and install beside commercial slipway.
3.2.2 Commercial Wharf and Floating Pontoon
The construction of the commercial wharf and floating pontoon involves two key components:
Offshore operations and land-based operations. The area for each section of works is outlined below.
3.2.2.1 Landward Operations
A 150-200t crawler crane shall be used for land-based operations, this will be sited on an engineered working platform that will be installed prior to commencing works.
1. Install six temporary piles. 310UB steel beams shall be used to create a temporary structure to set out pile positions. The temporary framework allows maximum of 8 piles to be installed at once.
Once the section is completed the temporary piles shall be removed and reinstated and the temporary structure shall be lifted and placed on to the following bent locations.
2. Install pile casings, place rebar cage, and pour concrete.
3. Land headstock on to the piles using the land-based crane. Temporary structure shall be moved further out to allow for workers to stand when landing cross head on to installed piles.
4. Place precast uni-span deck on to the head stock. Pour deck concrete. Installation of piles, landing of cross heads and placing and pouring deck shall be carried out progressively.
5. Remove temporary piles and install around next bent locations, install cross heads, and repeat previous process. Install pile casings, place rebar cage, and install concrete.
6. Land headstock on to the piles using the land-based crane. Temporary Structure shall be moved further out to allow for workers to stand when landing cross head on to installed piles.
7. Place precast uni-span deck on the head stock. Pour deck concrete. Installation of pies, landing of cross heads and placing and pouring deck shall be carried out progressively.
3.2.2.2 Seaward Operations
At the planned cross over point that the landward crane can no longer install works. Two flat top barges with its IHI CCH2000 Crawler cranes or similar shall be used of offshore operations. One barge will remain at the end of the wharf and complete majority of the works, with a smaller barge enabling completion of the section of wharf that is otherwise out of reach of both the landward crane and the main barge.
1. Six temporary piles shall be installed using the flat top barge. 310UB steel beams shall be used to create a temporary structure to set out pile positions. The temporary framework allows maximum of 8 piles to be installed at once. Once the section is completed the temporary piles shall be removed and reinstated and the temporary structure shall be lifted and placed on to the following bent locations.
2. Install pile casings, place rebar cage, and pour concrete.
3. Land headstock on to the piles using the flat top barge. Temporary structure shall be moved further out to allow for workers to stand when landing cross head on to installed piles.
4. Place precast uni-span deck on to the head stock. Pour deck concrete. Installation of pies, landing of cross heads and placing and pouring deck shall be carried out progressively.
5. Remove temporary piles and install around next bent locations, install cross heads, and repeat previous process. Install Pile casings, place rebar cage and pour concrete.
6. Land headstock on to the piles using the flat top barge. Temporary structure shall be moved further out to allow for workers to stand when landing cross head on to installed piles.
7. Place precast uni-span deck on to the head stock. Pour deck concrete. Installation of pies, landing of cross heads and placing and pouring deck shall be carried out progressively.
8. The installation of remaining works from a marine setting will be carried out including Pontoon installation to down river side of wharf.
3.2.3 Rock Revetment
1. Material for the rock revetment will be imported to and stockpiles on site.
2. Existing bank will be cut to depth, geotextile installed.
3. Under amour is to be placed, before amour rock is placed and secured. This will be undertaken in sections to minimize the exposure of the bank and shall receive Engineer’s approval prior to proceeding.
4. The rock revetment is to tie into the newly constructed Commercial Slipway and Commercial Wharf.
3.3 Earthworks & Roading Contract - Separable Portion 2 3.3.1 Pavement and Roading – Commercial/Parking area
Following the completion of the marine works a visual inspection of the entire site will take place, assessing the need for additional GAP65 basecourse. Where required, these areas will be topped up and compacted.
A GAP20 aggregate layer will be spread with a truck and trailer and leveled using a Total Station controlled grader and compacted with a 10-14T single drum vibration roller. The compacted surface will then be polished/locked off with a 12-14T static roller.
Compaction and dust control for the GAP20 operations will be supported by a 10,000L watercart.
3.3.2 Landscaping, Planting, and Signage
Hydroseeding and planting will be completed by a subcontractor.
Installation of signage and planting are provisional sums in the SoP. Once plant numbers and types are confirmed, these will be installed during an appropriate planting period.
Signage will be installed once design and placement are confirmed.
3.3.3 Reinstatement
Upon completion of the surfacing work and landscaping, the site will be cleaned, and any construction waste/material removed and taken off-site. Prior to disestablishment, a site walkover will be undertaken to confirm clean-up has been completed to the required standard.
