Archived decisions

Hampshire County Council

Executive Member - Environment

11 October 2002

Executive Member - Policy and Resources

16 October 2002

Project Appraisal: Bursledon Bridge Concrete Repairs

Report of the County Surveyor

Item 4

Item

Contact: Patrick Warrener, ext 6914

1. Summary

1.1 The following decisions are sought:

      (i) The Executive Member for Environment to agree:

        That the Executive Member for Policy and Resources be advised that the Executive Member for Environment supports the Project Appraisal for concrete repairs to Bursledon Bridge at an estimated cost of £600,000.

      (ii) The Executive Member for Policy and Resources to decide:

        That the Project Appraisal for concrete repairs to Bursledon Bridge at an estimated cost of £600,000 be approved.

2. Reason

2.1 The repairs of the bridge will prevent further deterioration and ensure that it can continue to support traffic using the A27.

3. Other Options Considered and Rejected

3.1 Continued deterioration would mean imposing a weight limit on the road and ultimately complete closure of the bridge, neither of which is considered feasible due to the importance of the road. There are no other realistic options.

4. Conflicts of Interest Declared by the Decision Maker or a Member or Officer Consulted - None.

5. Dispensation granted by the Standards Committee - Not applicable.

6. Reason(s) for the Matter being dealt with if Urgent - Not applicable.

Approved by: Date:

Councillor K B Estlin

Approved by: Date:

Councillor T K Thornber

HAMPSHIRE COUNTY COUNCIL

EXECUTIVE MEMBER - ENVIRONMENT

PROJECT APPRAISAL

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11 OCTOBER 2002

_____________________________________________

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PROJECT:

BURSLEDON BRIDGE - CONCRETE REPAIRS

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COMMENCEMENT DATE:

JANUARY 2003

COMPLETION DATE:

JANUARY 2004

PLANNED YEAR OF START IN ACCORDANCE WITH CAPITAL PROGRAMME: 2002/03

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____________________________________________________________________

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1.

FINANCE (Client Department, Director of Property, Business and Regulatory Services [Estates Practice] and County Treasurer)

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Current

Capital

Estimate

Programme

(at Aug 01

(at Aug 01

prices)

prices)

Capital Expenditure

£'000

£'000

Land to be purchased

nil

nil

Construction

550

550

Fees

50

50

600

600

Less developers/

other contributions

nil

nil

600

600

Financial provision for total scheme

Total Cost

1.

From Committees own resources

(a) Capital programme (as above)

600

(b) Other

2.

From other resources

(a)

(b)

(c)

TOTAL

600

Value of land for this project in HCC ownership £

Variations from capital programme

Revenue implications

£'000

% variation

to Committee's

budget

Net current expenditure

Nil

Nil

Capital charges

66

0.069

TOTAL net expenditure

66

0.069

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2.

STATEMENT OF NEED/JUSTIFICATION FOR PROJECT

(Client Department)

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Bursledon Bridge, illustrated on the attached location plan, carries the heavily trafficked A27 road over the River Hamble at Bursledon. The bridge, built in the early 1930s, is a three span reinforced concrete ribbed arch structure with a series of columns supporting the deck which in turn carries the road.

An extensive survey with material testing, carried out in March 2000, revealed that large areas of concrete have either cracked or spalled off due to corrosion of the steel reinforcement. This corrosion is due to inadequate protection being provided by the poor quality concrete and a high level of chloride salts present within the material. Cracking exists in nearly every element of the structure.

If work is not undertaken to repair the bridge and halt the deterioration, it will have insufficient strength to support the road and a weight limit, and ultimately closure of the road would be required. The road is very heavily trafficked, being of great importance to the local communities and non-motorway traffic. Any form of restriction would be extremely disruptive.

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3.

ROAD IMPROVEMENT PROPOSAL (Client Department)

____________________________________________________________________

National/County network and policies

The scheme is needed to discharge the County Council's statutory duty to maintain the highway.

Details of scheme and design standards

In order to carry out the concrete repairs it will be necessary to erect a suspended scaffold from the bridge, initially to the side spans and then the central span. Defective concrete will be removed by water jetting and exposed reinforcement cleaned or replaced as required. Propping will also be required in some areas, as it is anticipated that some of the columns will have insufficient strength to support the road once the concrete is broken out. A specialist repair mortar will be used to replace the concrete.

Additional works to improve the longevity of the bridge will also be carried out, these being the installation of sacrificial anodes to reduce future corrosion and painting the bridge with an anti-carbonation coating. In addition to helping protect the steel the coating will improve the appearance of the bridge by covering all the patchwork repairs. Wrapping the columns with a carbon fibre matting to strengthen them is also under consideration.

The work is expected to take six months and the proposed start date is January 2003. Closure of the central navigation channel will potentially have a significant impact on businesses upstream of the bridge. In order to minimise any disruption it may be necessary to phase the works and do the most sensitive work over the navigation channel in December 2003. This would enable businesses to plan ahead and experience gained in the first phase to be used in the more time sensitive part of the work.

Environmental impact

The bridge is within a candidate Special Area of Conservation (cSAC) and in close proximity to Sites of Special Scientific Interest (SSSI) and Special Protection Areas (SPA).

An ecological assessment is currently being undertaken by the Ecology Group to identify any special requirements for the contract but it is not thought that the works will have an adverse effect on these sites.

Land requirements

Not applicable.

Statutory procedures

The Environment Agency and English Nature have been consulted and applications for consent to undertake the work are in progress.

An application to the Department of Environment, Food and Rural Affairs has also been made, required under the Coast Protection Act 1949.

Public consultation

Discussions have been held with the Harbour Master and liaison will continue throughout the project. The district councils will be consulted at a later date once details are finalised.

Meetings have also been held with all the businesses upstream of the bridge that are likely to be affected by the works. Discussions will continue throughout the contract to ensure minimum disruption is incurred.

Facilities for the disabled

Works are not planned on top of the bridge and no specific provision is necessary to carry out the works.

Maintenance implications

Minimum maintenance is expected for the first 20 years following repair.

Local Members' View

The local Members, Councillors Estlin and House, have been consulted. Councillor Estlin supports the proposal. The views of Councillor House are awaited.

Crime and Disorder Act 1998

The provisions of this Act have no impact on this proposal.

Sustainability

Not applicable.

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4.

ROAD IMPROVEMENT - ALTERNATIVES CONSIDERED

(Client Department)

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The only alternatives are as follows:

(i)

Weight restriction

Apply a weight restriction with barriers to prevent HGVs using the bridge.

(ii)

Road closure

If no work is carried out this is the only safe long term option. Protection to river traffic would also be required.

Given the importance of the road neither of the above is considered an acceptable option.

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Section 100 D - Local Government Act 1972 - background papers

The following documents disclose facts or matters on which this report, or an important part of it, is based and has been relied upon to a material extent in the preparation of this report.

NB the list excludes:

1.

Published works.

2.

Documents which disclose exempt or confidential information as defined in the Act.

TITLE

LOCATION

Correspondence file

Technical and design files

County Surveyor's Department

Room 327

7311/PMW