As part of our ongoing work on Network Rail's CP6 delivery phase, we have been working with QTS Group on the Kirkconnel embankment project, part of the Glasgow and South Western Railway (GSW) Line.
The consultative approach to tendering that we use at Van Elle resulted in our providing a solution that steered away from the more traditional route; digging out the trackbed replacement and formation renewal, to provide a more cost-effective remedy.
This approach resulted in a substantial amount of time being saved, resulting in overall labour and plant cost efficiencies, but also a reduction in the need for taking material off and on site, which also made for a much more workable site environment.
Over a 10-day blockade, the works were been delivered safely, ahead of programme and to QTS's and Network Rail's satisfaction.
Our work onsite involved the installation 450 no. trackbed stabilisation (TBS) screw piles into the trackbed in order to reduce track settlement and improve track quality utilising the 4 No. Colmar T10,000 and Van Elle's own Spirit masts, which were developed in-house specifically for installing TBS screw piles.
The TBS screw piles are a part of Van Elle's Smartpile system, which offers distinct benefits ahead of alternative piling techniques such as grouted micro piles or driven tube systems. Installed from road/rail-mounted plant, the system utilises a modified screw pile technique with a patented pile cap. Typically, with this system, we can install a 4m long pile in less than five minutes. And, unlike grouted micro piles there is no risk of grout contamination and minimal heave of the subgrade or ballast layer. It also avoids the issues of ground disturbance associated with driven systems.
A second Network Rail infrastructure project that Van Elle has recently been involved with was the strengthening work on the Don Viaduct Bridge, which was built in Scotland in 1880.
On this project, BAM Nuttall's HEP team awarded the contract to Van Elle to install piles that would form part of a new shock absorber anchorage assembly to allow the Don Viaduct to remain in use for many more years to come
Working collaboratively, with all parties attending ongoing workshops, Van Elle and BAM along with the designers AECOM established a joint schedule of works based on the ground investigation knowledge available at the time.
The schedule of works included the installation of 32 no. 762mm spliced circular hollow section (CHS) piles to a depth of 10m (infilled with reinforced concrete) using one of our wheeled T10,000 and tracked T10,000 RRV (road rail vehicle) Colmars which incorporated a side grip Movax and 2.5t BSP hammer.
CHS casings were driven utilising the RRV's working in Rules of the Route possessions and following on from the CFA piling to mitigate the effect of the hydrostatic forces from below. A final pile depth of 17.5m was achieved, filling with concrete to support final pile and installing a substantial reinforcing cage, utilising one of our SR-30 CFA rigs.
The project presented opportunities for the business to unearth innovative solutions through joined-up thinking across our divisional disciplines to solve issues as they emerged. Working in collaboration with our specialist piling team, we finally installed 40 no. working piles (10 no. x 4 corners of the Don Viaduct structure) around 7-10 days ahead of published schedules. The technical knowledge and experience provided pivotal in the final solution delivered on the prestigious project.