TRU - Foundation Allocation Schedules (FAS)

30 March 2023
Image of railway tracks.
The Foundation Allocation Schedule on the Transpennine Route Upgrade project provides construction a detailed schedule to follow for installing structure foundations. These can vary from piled, concrete auger & gravity pad foundation types and provide additional details such as additional binders, pile caps or installation instructions. The Foundation allocation schedule is the prime responsibility of the Overhead Electrification team but does require input and review from Geotechnical and additional support from Civils disciplines on certain occasions. The schedule uses UKMS allocation design rules, system description manuals & technical drawings along with Network standards (see References) to calculate and product the required minimum foundation length the be installed.

The detail solution / approach

Breakdown of FAS data

There is a key for the Foundation allocation schedule in which only certain highlighted columns require inputting information. From this information the schedule will provide output data in the clear/white column which will provide construction with the required foundation lengths and allocations. There are also columns which are the responsibility of the Geotechnical discipline.

Structure details: The Project nomenclature and unique Foundation reference will be used for naming the structures shown on the OLE Plans, consisting of ELR or Route Prefix, followed by the Kilometrage or mileage and number of the structure.

Setting out details: These are the global values construction will use to position the foundations consisting of walkout (RECOS), GPS coordinates, Top of foundation level and bearings.

Location details: These records will inform construction of any know risks or works to monitor or be aware of when installing the foundations such as drainage, ecological (environmental), poor earthworks, mining and topographical category data.

Trial hole status: This is used to inform construction of the current trial hole survey status of the proposed foundation location.

General: Notes are used add and inform construction of any required additional data for example CDM significant risks information. Also input location ground conditions in like with UKMS approved technical drawings B98/K04, B98/K05 & B98/K08 and structure location values.

Foundation details: This the foundation details which will be used in calculating the foundation lengths.

Foundation Depth Calculation details

In this section of the foundation schedule the user inputted foundation details and ground conditions are used to call up, generate and calculate the minimum foundation lengths required in line with UKMS approved technical drawings B98/K04, B98/K05 & B98/K08. These output values are then used to inform the sheet to look up the require allocatable length and allocation details and shown in the foundation details for construction.

Structure / Foundation loading values

This the overturning moment loading that will be applied to foundation as per UKMS approved drawing B98/K04. This process was carried out on TRU area W1 & W2A using loading calculation tools or by using approved standardised worst case load values.

Note: These values are also used to review the acceptance of adaptor plates in checking that the Across and Along track movements do not exceed the permissible zone stated in the UKMS drawings (see B83/B05 & B83/B08 for graph examples).

Geotechnical discipline works

There are three columns that geotechnical are to prove details and take responsibility

Mining Risk: Location are categorised into three colours for mining.

  • Green represents locations where ratio for rock cover to mining seam thickness exceeds 10:1 and is considered low risk.
  • Amber represents ratio for rock cover to mining seam thickness equal to or less than 10:1 but exceeds 5:1 and is considered moderate risk.
  • Red represents ratio for rock cover to mining seam thickness equal to or less than 5:1 and considered higher risk.

With cases of Amber or Red risked area if unable to relocate to foundation location to alternative Green areas Piling detail is unable to be used and Geotechnical will be required to review alternative solutions such as concrete augers, gravity pad or other bespoke solutions.

Poor Earthwork Risk: this is standard yes/no column which Geotech provide once review the proposed location ground conditions.

Design Method: This is the design methodology to be used to calculate the foundation length. ORE method uses the location and calculations written into the schedule in line with the UKMS approved technical drawings B98/K04, B98/K05 & B98/K08 and is for a standard CHS piles & Auger foundation type. Methodology type EC2/EC7 is used for bespoke CHS piles (example - tie locations) and Gravity pads.

Reference Standards

  • NR NR/GN/CIV/003 ISSUE 1 - Guidance on Engineering and Architectural Assurance of Building and Civil Engineering Works
  • NR NR/L2/CIV/072 ISSUE 2 - Wind Loading of Overhead Line Equipment and Structures
  • NR NR/L2/CIV/073 ISSUE 1 - Design of Overhead Line Structures
  • NR NR/L2/CIV/073/F001 ISSUE 1 - Design of Overhead Line Structures: Design of OLE Structures to Eurocodes
  • NR NR/L2/CIV/074 ISSUE 2 - Design and Installation of Overhead Line Foundations
  • NR NR/L2/ELP/27715 ISSUE 3 - Overhead Contact System Design Specification
  • NR NR/L2/ELP/27715/MOD 02 ISSUE 1 - Overhead Contact System Design Specification: Module 2 Allocation Design Principles
  • NR NR/L2/ELP/27715/MOD 03 ISSUE 1 - Overhead Contact System Design Specification: Module 3 Design of Auto Transformer Feeders and Ancillary Conductors
  • NR NR/L2/ELP/27715/MOD 04 ISSUE 3 - Overhead Contact System Design Specification: Module 4 Electrical and Mechanical Clearances and Separation
  • NR NR/L2/ELP/27715/MOD 05 ISSUE 1 - Overhead Contact System Design Specification: Module 5 Engineering Deliverables
  • NR NR/L2/ELP/27715/MOD 06 ISSUE 1 - Overhead Contact System Design Specification: Module 6 Governance of Overhead Contact System Design
  • BSI BS EN 50119 - Railway applications - Fixed installations - Electric traction overhead contact lines

Outcomes and benefits

The usage and submission of a foundation allocation design schedules to construction is a preference as it can be issued at an earlier stage than the detailed wiring allocations and therefore allow construction to procure and install foundations at an earlier stage, reducing program timescales and cost. It also reduces the amount of information construction need to install the foundations as they only require the schedule per construction unit and do not need to take individual sheets per location.