Doha, Qatar, December 2007.
GGL trained site operatives in tendon fabrication, grouting , installation and testing single bore multiple anchors (SBMAs) in Qatar during December 2007. In highly weathered and fissured Simsima Limestone tested loads of up to 1920kN were achieved without failure. The programme of works also involved the testing of removable SBMAs. After satisfactory proof testing in accordance with PTI (2004) the tendon were completely removed in safe and controlled operation (see below).
On Site Development of Corrosion Protection for Permanent Anchorage Works in Amman, Jordan
Ground anchorages, required for the provision of holding down forces and prevention of overturning, were installed during the construction of the Wadi Abdoun Bridge in Amman, Jordan.
The acceptance criteria for the permanent work anchors demanded double corrosion protection to standards not readily available with the components originally supplied.
Dr Devon Mothersille of Geoserve Global supervised the tendon fabrication, the encapsulation, grouting and preliminary site trials to ensure the maintenance of high standards of workmanship and compliance with the British Code of Practice BS 8081:1989 and the new Euro code for Anchorages – EN 1537:2000.
Pre-Production Test carried in Boston Clay using Single Bore Multiple Anchor technology.
In August 2007 GGL assisted a USA based contractor with a series of field trials using the single bore multiple anchors in Boston Clay. The carefully supervised work successfully demonstrated test loads of up to 1200kN which exceeded the load capacity achieved with conventional anchor systems.
During incremental loading of the individual unit anchors simultaneous plotting and analysis of load extension data was undertaken to allow an immediate assessment of fixed anchor behaviour and apparent free tendon length.
Construction of large diaphragm wall in Barcelona
Dr Devon Mothersille acted as Independent consultant to the Hines Corporation, working in close collaboration with other international experts, during the construction of large diaphragm wall in Barcelona. Operating remotely from the UK and on site in Barcelona, he provided advice and technical support to the client and the engineering staff on many aspects including design, construction, testing, corrosion protection, forensic investigation, quality control and monitoring of ground anchor systems.
Anchor head inspections on the River Clyde, Glasgow
Geoserve Global Ltd were commissioned to undertake detailed inspections of anchors heads, used as an integral part of the ground anchor support system for quay walls on the River Clyde, Glasgow. The primary objective of the inspection programme was to allow categorisation of the anchor head corrosion. Since there is no method established in the anchor industry for accurately predicting the future performance of corroded anchor components, destructive tests on some in situ anchor components were implemented together with load testing and metallurgical analysis. The works also included several exhumations of selected anchors and tie-rod support systems to investigate their condition after some 40 years in service.
Rock Anchorage installations for the stability of the Burnley Tunnel, Melbourne, Australia
Instability at floor level of the Burnley Tunnel, imposed by large hydrostatic forces, required the installation of some 5000No rock anchorages. The anchorages were installed along a 2km section of the tunnel, as part of a remedial works program on the Melbourne City Link project, Australia. As an independent consultant, Dr Devon Mothersille was responsible for site supervision, quality control, training of operatives, technical support to client and contractor, and analysis of on-site acceptance testing data.
Developing a ground anchor system for an Australian Geotechnical Engineering company
In 2001 the team was commissioned to develop a ground anchor system for an Australian Geotechnical Engineering company. This extensive program of work involved comprehensive testing of all developed components for the proposed low to medium capacity strand anchor systems. Work included pressure and impact tests on the corrugated ducting used to isolate the tendon from the environment and thereby provide protection against corrosion. In order substantiate the proposed system, full scale gun barrel and grout simulation tests were carried out. Every material type utilized within the system was researched and the results included in detailed materials specifications. Finally the results from all performance tests and anchor fabrication processes were documented in a series of reports.
On completion the system formed the first proprietary anchor system developed from source in Australia.