Report to INFRASTRUCTURE SERVICES Committee for noting

Transcription

1 Subject: Prepared by: Capital Works Programme 2015/16 Tairāwhiti Roads Alexios Kavallaris (Capital Manager - Tairāwhiti Roads) Meeting Date: 22 October 2015 Report to INFRASTRUCTURE SERVICES Committee for noting SUMMARY The purpose of this report is to inform the Committee of three resilience projects (1-3) and three heavy productive motor vehicle bridge strengthening projects (4-6): 1) Anaura Bay Road (Nuhiti) rock revetment 2) Southern Seawall Repair, Beach Road, Tokomaru Bay 3) Mata Road Realignment R.P ) Horoeka and Te Pahi bridges deck strengthening 5) Gaddum s bridge strengthening 6) Mata (Huiarua) bridge deck replacement A Powerpoint presentation of the projects will be provided at the meeting. RECOMMENDATIONS That the Committee 1. receives the report. Alexios Kavallaris Capital Manager Tairāwhiti Roads Barry Vryenhoek Operations Group Manager Keywords: Tairāwhiti Roads, land transport, capital projects A Page 1 of 6

2 1. BACKGROUND Six capital projects have been approved for funding in the financial year. are: These 1.1 Anaura Bay Road (Nuhiti) Rock Revetment The works are to partially construct two rock revetments with buttress fill behind whilst beginning earthworks for a future road realignment of approximately 220m length of the Anaura Bay Road. This was a high priority as it was a commitment to the residents and landowners affected by consistent road closures. The seaward slope is being undermined by erosion from the action of the sea, which has resulted in the regression of the slope and a reduced road formation width. The damage is a result of a combination of factors including tides, current and wave action from the ocean as well as the mobilisation of the slip upslope of the road. The future road realignment is intended to cut the road further inland into more stable material and take weight off the top of the slope. The revetments to be constructed on the seaward side of the buttress fill are intended to reinforce the toe of the slope. This is expected to protect the toe from further erosion and help stabilise the existing slips. The future placement of topsoil, grass seeding and planting of the slopes below the new road will provide additional stability. Works include clearing the site of vegetation, stripping of topsoil, excavation of loose slip material at the toe and on the face of the seaward slope, some excavation for the construction of the new road with the excavated material being placed as buttress fill on the beach against the seaward slope and the partial construction of the rock revetments. The works are for Stage 1 of the four stage construction sequence. This stage is for the construction of approximately one quarter of the rock revetments and a portion of the earthworks relating to cutting in the road realignment along with buttress fill behind the rock revetments. Fill for the buttress is to be gained from the road cutting. Estimated Total Cost for Stage 1: $250,000 Preliminary design drawings completed Community consultation in progress Resource consent in progress Archaeological report in progress Mangatuna quarry consenting yet to begin Detailed design and contract documentation currently in progress Will proceed to construction open tendering by February 2015 Anticipated construction period for Stage 1 is 3-4 months A Page 2 of 6

3 Current status Community consultation in progress Resource consent in progress 1.2 Mata Road Realignment R.P This section of road has been slumping/subsiding for many years. Additional to this there is a large volume of heavy traffic and poor road width and visibility. There have been many requests from the public, local councillors, landowners and road users to improve this section of road. Currently the road can be restricted to one way only. Road users are unable to see oncoming traffic and the use of radio to communicate is the only way to negotiate this section of road safely. Not everyone has a radio. Option 1 - Carry out road alignment which would benefit the visibility of the road. Option 2 - Stay with the existing road alignment and widen the roadway, carry out sight benching and remove vegetation to improve sight visibility. With both options there will still be ongoing issues with the stability of this site. A neighbouring landowner has agreed to Council gaining access and utilising his land to enable improvement works. Estimated Total Cost: $250,000 Investigation phase in order to produce an options report and agree on the engineer s preferred option. Apply for resource consent with Council and progress consultation with stakeholder for the option that needs land acquisition. Preliminary and detailed design. Contract documentation and tender process. Progressing with investigation to produce options report due by 21 November Southern Seawall Repair, Beach Road, Tokomaru Bay The concrete seawall alongside Beach Road, Tokomaru Bay, has been damaged. There is a large hole in the wall that is causing backfill to be lost from behind the wall. This has been covered by a steel plate as a temporary measure but a more permanent solution is required. The scope of the permanent work is to remove the temporary plate and repair the concrete wall. This includes: Dewatering and protecting the repair area from the ocean. Removing the temporary plate and fixings. Excavating the material from in front of the wall down to bedrock. Removing all loose material from the damaged area and preparing the exposed concrete and reinforcement. Drilling and epoxying MateenBar reinforcing into the walls and base of the damaged area. A Page 3 of 6

4 Inserting and grouting seepage pipes. Placing concrete repair material. Placing rock rip-rap against the toe of the new repair. The scope of the permanent work is to repair this erosion. This includes: Dewatering and protecting the repair area from the ocean. Excavating the material from in front of the wall down to bedrock. Removing all loose material from the area and preparing the exposed concrete and reinforcement. Cutting the bedrock foundation to the correct profile. Drilling and epoxying MateenBar reinforcing into the existing concrete. Placing the concrete repair material. Backfilling behind the existing seawall. Placing rock rip-rap against the toe of the new repair. Estimated Total Cost: $300,000 Project will be staged as $150,000 is only available this financial year. Investigation of both buttress and seawall repair done. Detailed design and contract documentation completed by December Construction period from February to April Resources consent to be finalised once final design completed. 1.4 Horoeka and Te Pahi Bridges Deck Strengthening To carry out an assessment of two bridges on Waimata Road: Horoeka Bridge at RP 9.85 and Te Pahi Bridge at RP Both bridges previously assessed in 2006 giving >100% Class 1 (>44t gross weight). Reassessment of these bridges was considered necessary as new evaluation methods have since been introduced and also to determine their capacities to accommodate High Productivity Motor Vehicles loading. Estimated logging activities forecasting in tonnes is shown below: Accumulated volume Waimata Hokoroa 2016/ / / / / / /24 Tonnes 85, , , , , , ,000 1,327,496 Estimated Total Cost: $120,000 for both bridges A Page 4 of 6

5 Investigation assessment done. Benefit cost ratio, detailed design and construction drawings done. Construction estimate and contract documentation due by 16 October Open market tender by mid-november Construction estimate and contract documentation. 1.5 Gaddum s Bridge Strengthening Gaddum s Bridge is at 6678 Matawai Road and carries a single lane carriageway over the Motu River. The structure is a single span castellated steel bridge with timber deck founded on concrete abutments. The bridge is to be upgraded to allow tanker access. This involves strengthening the main girders primarily but also increasing support capacity to the central beam of the bridge. The timber deck will also be replaced with a new timber deck. Timber was deemed more appropriate than concrete as it will be lightweight and therefore will not put too much additional load onto the existing abutments. Scope of works includes: Access Traffic Management Demolition Steelwork Timberwork Barrier installation Corrosion protection Estimated Total Cost: $200,000 Investigation assessment done. Preliminary and detailed design done. Construction estimate and contract documentation done. Open market tender in progress, closing date for submission 23 October 2015 Open market tendering. 1.6 Mata (Huiarua) Bridge Deck Replacement The site of work is at the Mata (Huiarua) Bridge on Mata Road (Upper). This site is located 116km north of Gisborne, 35km west of Tokomaru Bay. Once the bridge is complete, Mata Road will be fully enabled for HPMV capability. A Page 5 of 6

6 This project involves replacing the existing deck on Mata (Huiarua) Bridge on all four spans in order to increase the carriageway width and improve the live load capacity to full HPMV. The work involves: Remove existing deck and guardrails. Shear stud installation. Precast concrete deck with in-situ infills. Joint installation. New galvanised steel protection barriers. Minor earthworks. Seismic steelwork retrofit. Paint beam top flange and seismic steelwork. Traffic management. Liaison with service authorities and local landowners. Estimated Total Cost: $500,000 Project was tendered in December Contract awarded on February Contract postponed allowing for Ernslaw One to reprogramme their operations due to potential bridge closure. Contract recommences on 26 October 2015 and estimated completion either before Xmas break or one week after Xmas holidays. Suspension period until 26 October A Page 6 of 6