NG1 Introduction
NG1 Introduction
1) The primary objectives of this Specification are to ensure that all Undertakers' reinstatements, within roads, are completed to a permanent standard, as soon as is practicable and to a consistent high quality. Undertakers and Authority personnel should work together, in close co-operation, in order to achieve these objectives.
2) This Specification may require a joint inspection of any reinstatement site, depending on the existing site conditions, before the commencement of works. Such joint pre-inspections may be of an informal nature, by agreement, and should be carried out at the earliest convenience of both parties. Where either party fails to attend any agreed pre-inspection, or where existing site conditions warrant concern, it is recommended that the Undertaker retains a photographic record of the existing surfaces, prior to the commencement of works.
3) This Specification may require a formal notification of circumstances or other requirements, depending on the existing conditions of any reinstatement site, prior to the commencement of works. Such pre-notifications should be issued at the earliest possible opportunity. Undertakers shall comply with such notification issued at the road works notice stage, and should make reasonable efforts to comply with any notification issued thereafter.
4) Where this Specification allows several options, it is recommended, wherever practicable, to agree a preferred option from the alternatives available. This principle should be applied to all sections where alternatives are provided.
1) Where an Authority intends to resurface or reconstruct a section of road, the Undertaker may complete any reinstatement to an alternative interim standard, by agreement. The guarantee period shall thereafter be waived, unless the Undertaker's reinstatement can be shown to be grossly substandard. It is expected that agreement to this procedure will be conditional upon all savings in costs made by not carrying out a permanent reinstatement being shared, equally, between the Undertaker and the Authority.
2) Where site circumstances are considered to mitigate against a successful permanent reinstatement, an additional interim period of up to a further 6 months may be adopted, before it is necessary to complete the permanent reinstatement.
3) In designated high amenity locations and areas with high quality surfaces there is benefit in completing the permanent reinstatement immediately or as expeditiously as possible. To facilitate a permanent reinstatement, materials need to be identified and ordered early in the works planning process. Advance notification through the SRWR is necessary to achieve this and the Authority should assist the Undertaker to locate sources of suitable similar or equivalent modules, especially if no stocks are available from the Authority itself.
1) Road categories 0 to 4 are based on the number of millions of standard axles (msa) carried by the road over a 20-year period. Reinstatements are designed on this basis. The traffic loading is calculated in accordance with HD 24/06:
2) It is not possible to match the engineering integrity of existing well-consolidated unbound layers with unbound reinstatement materials. Therefore there may be significant differences between the existing carriageway construction and the requirements of the Specification. The increased thickness of reinstatement materials compensate for this.
3) Where one-way traffic systems and/or other traffic management schemes result in multi-lane traffic, standard growth rate predictions and lane correction procedures may result in an inaccurate road classification overall. In such cases, whenever reasonably practical, the flow of commercial vehicles should be monitored separately, and traffic calculations completed for each traffic lane.
4) Where an existing road is near, or beyond, its service life, and is expected to be re-constructed within the foreseeable future, a temporary re-classification of the road will usually be appropriate, pending its re-construction. Such temporary re-classifications should be undertaken by agreement between the parties involved. Similarly, where roads are expected to be re-constructed within the guarantee period of the reinstatement, it will usually be appropriate to amend methods, materials or performance requirements for those reinstatements, by agreement.
NG1.4 - There are no Notes for Guidance
NG1.5 - There are no Notes for Guidance
1) New Materials
Research into new or improved reinstatement materials is often undertaken by various organisations and such work may produce materials that perform as well as, or better, than those given in this Specification. In order to allow such materials to be proven by development testing, the materials and relevant layer thickness quoted in this Specification may be amended or supplemented, subject to prior agreement with the roads authority.
2) Local Materials
Materials may be available locally that have not been defined in any national Specification, but which, by experience, are known to give acceptable performance in service. In order to allow the use of such local materials, the materials and relevant layer thickness quoted in this Specification may be amended or supplemented, subject to prior agreement with the roads authority.
3) Alternative compaction equipment
Alternative compaction equipment, including any compaction device, not specifically permitted within Section S10 and Appendix A8, may be permitted, provided it has been proven to be capable of achieving the performance requirements permitted in Section S10, Appendix A2 and/or Appendix A8.
a) For all compaction plant not shown in Appendix A8, an approved operating procedure should be established, by development testing, in an appropriate trench environment with the relevant material options to meet the performance requirements permitted in Section S10, Appendix A2 and/or Appendix A8. The development testing may be verified by an independent, accredited laboratory.
b) Where alternative compaction plant is intended to be used on more than one type of material, as defined in Appendix A8, an approved compaction procedure shall be established, as defined in section NG1.6 (3) (a) above, for each intended category of material.
The minimum thickness of bituminous surfacing material, required by Section S1.7.1 for the reinstatement of all immediate works, is 40 mm. A greater thickness may be required, in areas subject to frequent or heavy traffic, if further remedial works, during the 10 days permitted duration of immediate works, are to be avoided.
NG1.8 Apparatus within the Road Structure
1) Some apparatus may already be present at shallow depth, within many existing road structures and special requirements may apply to their reinstatement. Both the Undertaker and the Authority are likely to have particular criteria and this Specification may be altered, or supplemented, subject to prior agreement, to accommodate any such requirements.
2) Not all new apparatus will need to be installed to the full depth or width expected by this Specification; an example is small diameter cabling and/or ducting for telecommunications, traffic controls, etc. This Specification may be altered, or supplemented, subject to prior agreement with the roads authority, to accommodate these applications. Shallow apparatus should be recorded.
NG1.9 Geosynthetic Materials, Geotextiles and Reinforcement Grids
Where these materials are used, the manufacturer's instructions shall be followed, particularly in relation to appropriate overlaps, fixing and the like.
NG1.10.1 Prohibited, Precautionary and Permitted Zones
PROHIBITED ZONE - 1m from trunk. Excavations of any kind must not be undertaken within this zone unless full consultation with Local Authority Tree Officer is undertaken. Materials, plant and spoil must not be stored within this zone.
PRECAUTIONARY ZONE - beneath canopy or branch spread. Where excavations must be undertaken within this zone the use of mechanical excavation plant should be prohibited. Precautions should be undertaken to protect any exposed roots. Materials, plant and spoil should not be stored within this zone. Consult with Local Authority Tree Officer if in any doubt.
PERMITTED ZONE - outside of precautionary zone. Excavation works may be undertaken within this zone however caution must be applied and the use of mechanical plant limited. Any exposed roots should be protected.
NG1.10.2 Precautions during Excavation and Reinstatement
1) THE PROHIBITED ZONE
Don't excavate within this zone.
Don't use any form of mechanical plant within this zone.
Don't store materials, plant or equipment within this zone.
Don't move plant or vehicles within this zone.
Don't lean materials against, or chain plant to, the trunk.
Do contact the local authority tree officer or owner of the tree if excavation within this zone is unavoidable.
Do protect any exposed roots uncovered within this zone with dry sacking.
Do backfill with a suitable inert granular and top soil material mix as soon as possible on completion of works.
Do notify the local authority tree officer or the tree's owner of any damage.
2) THE PRECAUTIONARY ZONE
Don't excavate with machinery. Where excavation is unavoidable within this zone excavate only by hand or use trenchless techniques.
Don't cut roots over 25mm in diameter, unless advice has been sought from the local authority tree officer.
Don't repeatedly move / use heavy mechanical plant except on hard standing.
Don't store spoil or building material, including chemicals and fuels, within this zone.
Do prune roots which have to be removed using a sharp tool (e.g. secateurs or handsaw). Make a clean cut and leave as small a wound as possible.
Do backfill the trench with an inert granular material and top soil mix. Compact the backfill with care around the retained roots. On non road sites backfill only with excavated soil.
Do protect any exposed roots with dry sacking ensuring this is removed before backfilling.
Do notify the local authority tree officer or the tree's owner of any damage.
3) THE PERMITTED ZONE
Don't cut roots over 25mm in diameter, unless advice has been sought from the local authority tree officer.
Do use caution if it is absolutely necessary to operate mechanical plant within this zone.
Do prune roots which have to be removed using a sharp tool (e.g. secateurs or handsaw). Make a clean cut and leave as small a wound as possible.
Do protect any exposed roots with dry sacking ensuring this is removed before backfilling.
Do notify the local authority tree officer or the tree's owner of any damage.
NG1.11 There are no Notes for Guidance