North Coast Curve Easing - URS Australia (now AECOM)

Project Summary

This project’s aim was to decrease train times by increasing rail curve radii in order to increase speed on the north coast rail line from Newcastle to Brisbane. The project included a large number of selected sites within this length of rail slewing from 1 to more than 5 curves per site.

The Challenge

The client requested benching/terracing to be modelled in 12d Model for accurate volumes, and construction setout as the rail embankment needed to be constructed in 600mm layers. They had had problems in the past with this area being overlooked and volumes being inaccurate, so URS needed a very easy to apply, uncomplicated dynamic for design changes, and a non-time-consuming way of doing this as it was required on almost all of the 50+ sites for the project.

Setting up a template that would need to be constantly modified by inserting/omitting strings due to changes in heights of the embankment, and also widths of benching, etc., was not optimal, nor was setting up a decisional template as it would be too full of glitches and hard to modify for specific cases, inaccuracies in the survey, etc.

The idea then came to fix the problem by using a variable fill template that would add and omit benching steps as the embankment heights changed, making it dynamic and very easy to work with, plus making it easy to modify benching widths, useful if e.g. there were a flat section as part of the embankment.

The Solution

1. A Dummy embankment foundation function was created to be the base of embankment works. This was hinged off the proposed toe of the embankment and offset due to topsoil removal. A tin was then created from this.
2. A template with the benching/terracing strings placed all within the ‘fill’ section of the template was created. The template could contain 50+ strings to allow for embankments of any size.

The Result

This very simple but effective solution was used in over 50 sites on the project, and worked very well. It is a great example of 12d Modellers ‘thinking outside the box’.