In October 2019, EMS Geotech undertook Plate Load Testing at the development site for The Midlands Centre for Cyber Security in Rotherwas, Hereford. The work was commissioned in order to validate whether a compacted hardcore layer could safely support two models of crane to be used for lifting the RSJ frame sections for the building development.
The development, which is a joint venture between the University of Wolverhampton and Herefordshire Council is being built on Skylon Park in the Hereford Enterprise Zone. The aim of the development is to tackle the growing threat of cyber security – a threat which becomes more and more real as we rely heavily on technology to run our daily lives.
The state-of-the-art centre is scheduled for completion in Summer 2020 and will feature a three-storey research space and teaching building for the University of Wolverhampton’s Cyber Security Research Institute. In addition, it will provide tenanted office space for up to twenty local cyber security businesses.
The Plate Testing undertaken by EMS Geotech on the site was carried out in accordance with BS 1377:1990 and outlined by Tomlinson (1980). This technique uses a reaction weight (kentledge) and is usually provided by a mechanical excavator. Generally, the topsoil is removed and the steel plate ‘bedded’ onto the soil to provide uniform contact across the full diameter of the testing plate. This requires the use of sand and/or cement mortar.
In this instance the compacted hardcore was already in place on the site, and suitably level to allow the testing to begin. Loading was applied in increments of approximately one fifth of the design loading and held in place until the settlement reduced to <0.004 mm/min.
The load increments are applied until shear failure occurs or the plate pressure reaches two or three times the design bearing pressure proposed. In this case, the maximum pressures exerted on a single pad of the two crane models were calculated based on the maximum load capacity listed in their technical specification. This data was plotted and the yield stress recorded. (If the yield stress is not observed during the course of the testing, then the ultimate bearing capacity has not been reached.)
The settlement value observed from the data collected was then assessed to determine the adequacy of the hardcore layer to support the cranes that would be on site as part of construction works. This is important for Health & Safety and to avoid toppling. Other sites may require this type of data to inform the suitability of the foundation design.
All data was tabulated, displayed graphically, interpreted and presented in an interpretive letter report and issued to the client.
EMS Geotech look forward to seeing the completion of the project in 2020.
For more information regarding the project click here
