HS2 will be the UK’s zero-carbon, high-speed railway, which has been taking shape for the last three years. This major initiative is the largest ever rail investment to have been made in the UK and the biggest infrastructure project in Europe.
MGF’s dedicated Rail/HS2 Team who are on hand to provide expert help and guidance in relation to HS2 enquiries.
MGF was invited by contractor J Murphy and Sons Ltd, on behalf of Severn Trent Water (STW), to provide a temporary works solution associated with works done in preparation for the construction of HS2.
Temporary excavation support was required to enable a proposed undertrack crossing to be installed beneath the new HS2 line.
Due to the location of the proposed new pipelines, there was an existing water main crossing the proposed path that needed supporting whilst the new pipelines were installed.
The unsupported section of pipe was approximately 12m long. However, the exposed service required support over an 18m clear span.
In addition to the service support, there was a requirement for a 20m x 5.7m x 5.0m deep excavation. This was to facilitate the installation of the new concrete pipe sections, directly below the service support.
It was not possible to install sheet piles where the existing service entered the excavation. An alternative support system was therefore required over a width of approximately 3.5m around the pipe entrance.
Traditional timber lagging was not suitable due to the distance between the primary supports. A more robust solution was necessary to resist the resultant earth pressures from the cofferdam and additional reaction loads from the service support system.
Burton Green HS2 Line
Severn Trent Water
J Murphy and Sons Ltd
Lee Womersley, Engineering Manager
Using an integrated structural solution to overcome complex challenge underneath HS2, whilst minimising disruption to the network and ensuring protection of the network
A two-stage excavation support system enabled concrete pours to be progressed. A modular 305UC Brace with twinned 300 series struts at mid-span to maximise the digging window around the upper frame was specified, with 4N° bays, comprising a back-to-back 254UC Brace being specified for the lower frames, which facilitated the pour sequence.
A King Pile System was constructed at the point where the service support entered the excavation. MGF trench sheets were installed horizontally to sufficiently help transfer the earth pressures into the primary king piles. This design made sure there were no clashes with the existing pipework above.
Due to the limits, a modular Warren Truss was designed in-house by MGF’s Engineers, using its versatile proprietary UniShore system. Standing at 1.7 metres tall, the truss spanned the full distance between the supports and was pre-assembled at the site.
A cradle frame was also designed to protect the existing service from accidental impact during excavation works. To support the onsite team with lifting the prebuilt truss into place, our lifting division specified and supplied the contractor with one of our 6m S80 modular spreader beams.
By choosing MGF, J Murphy and Sons Ltd was provided with a fully comprehensive solution that overcame all of the complex challenges associated with providing the required temporary support.
A highly versatile, medium duty modular bracing strut system, designed primarily for use in conjunction with hydraulic bracing systems. For …
Designed to brace large/deep cofferdams for the safe installation of underground structures, deep drive/thrust pits or basements. Double acting hydraulic …
Designed to brace medium to large cofferdams and trenches, allowing safe installation of large underground structures, deeper drive/thrust pits or …
Whether you have a question, need a quote, or want to discuss a project, our dedicated team is ready to assist you.
