This standard sets out the minimum requirements and specification for a temporary access road to facilitate construction, the installation of plant or low frequency maintenance.
Owner:
Mark Dunk
Date:
09/05/2014
Approved By:
Barry Hatton
Approved Date:
27/05/2014
Review Date:
27/05/2017
This document forms part of the Company’s Integrated Business System and its requirements are mandatory throughout UK Power Networks. Departure from these requirements may only be taken with the written approval of UK Power Networks’ Director of Asset Management. If you have any queries about this document please contact the author or owner of the current issue.
Document History (The document history notes below are intended as a guide only and may not cover all of the changes. If you wish to make use of this document it should be read in full.)
Version
Date
Details
Author
1.0
09/05/2014
Original (for publication on G81)
Mark Dunk
THIS IS AN UNCONTROLLED DOCUMENT, THE READER MUST CONFIRM ITS VALIDITY BEFORE USE
On occasions it is necessary to construct a temporary access road suitable for general short term or low frequency vehicle access and for plant delivery either before or in place of a permanent infrastructure system. This Engineering Standard provides details regarding the specification and construction of such a temporary access.
2
Scope
This standard applies to all Capital Programme or Connections major project works prior to the installation of permanent infrastructure or to facilitate plant replacement where permanent infrastructure is not present. This standard can also apply to Networks Operations plant replacement projects where no or insufficient road infrastructure is in place. This standard sets out two options, a temporary access road for use in Networks projects to facilitate light vehicle or one–off plant delivery access prior to the installation of the permanent road infrastructure and an un-metalled, unreinforced road to be used on Connections projects where plant and installation vehicle and occasional maintenance vehicle access is required for the life (typically 25 years) of the installation (e.g. solar farm installations) but where a fully surfaced access road is not technically or economically viable. It is to be noted that neither road is to be used to support out-riggers from delivery or operational vehicles without checks regarding the suitability of the installation by a competent person. For permanent roads on UK Power Networks operational property the standard set out in EDS 07-0105 ‘Grid and Primary Substation Civil Standards’ is to be used.
3
Temporary Access Road (Networks)
3.1
Construction Method
Following standard checks for above and below ground services and obstructions:
3.2
A 150mm deep excavation is to be made; The excavation should be between 3500mm (for standard vehicle access) and 4500mm (for major plant installation, removal or replacement); Once complete the excavation should be lined with Terram 1000 geomembrane or similar approved, and; 150mm of Type 1A material placed, compacted and rolled to an even surface finish and a 1% gradient from one side to the other. Specification
Specification, placing and compaction of materials shall be in accordance with those detailed in EDS 07-0105 for Building and Civil / Structural Works 3.3
Works Completion
Following completion of the works the temporary access road should be removed and the area made good to original ground level or incorporated into the permanent road infrastructure.
Because of the extended longer operational life requirement expected of this road it is necessary for construction to be more robust than that of the short term temporary access road detailed above. The access shall be designed to accept a minimum axle weight of 11 tonnes and incorporate an adequate turning bay if access is possible from one direction only. The depth of sub-base, and consequently the depth of construction, will vary according to the CBR value of the substrata; these variances are detailed in the table in Section 7. Following standard checks for above and below ground services and obstructions and assuming that the minimum CBR is 3% then:
4.2
A 410mm deep excavation is to be made, the excavation should be a minimum width of 3500mm. Once complete the excavation should be lined with Terram 1000 geomembrane or similar approved 310mm of 6F2 or 6F5 material placed, compacted and rolled to create the roadway subbase layer. The sub-base layer is then to be capped with minimum 100mm Type1A material compacted and rolled to an even surface finish and a 1% gradient from one side to the other. Specification
Specification, placing and compaction of materials shall be in accordance with those detailed in EDS 07-0105 for Building and Civil / Structural Works.
5
References
EDS 07-0105
6
Grid and Primary Substation Civil Design Standards
Dependent Documents
This document should be read as an annex to the documents listed below: EDS 07-0102
Secondary Substation Civil Design Standard
EDS 07-0105
Grid and Primary Substation Civil Design Standard
EDS 07-0020
Civil Requirement for New Customer Supplies and Generator Connections between 6.6 and 33kV
The drawing below outlines the basic cross-section details of the temporary access roads referred to in this document: Diagram 1: Networks project short term access road
Diagram 2 above assumes a minimum CBR of 3%, the depth of subgrade will need to be varied depending on the CBR value of the substrata in accordance with the table below:
Granular Sub-base Thickness CBR 2%
CBR 4%
CBR 5%
370mm
240mm
200mm
Substrates with a CBR of less than 2% will require stabilisation and reinforcement prior to the road being constructed.
