In collaboration with foundation contractors Bauer (Qatar) and Bauer (Abu Dhabi), SBMA Ltd was engaged to design and supply the ground anchors that form an integral part of the excavation support system for the Qatar Petroleum Multi-Storey Car Park in Doha, Qatar. Construction of the 14m deep excavation will be in ground described as highly weathered Simsima Limestone. SBMA Ltd has developed a substantial amount of anchoring experience in this type of rock, having worked in the region on significant foundation projects before.
The unusual feature of this project is that the specification stipulates that the anchors are to be removable with a design service life of 10 years. Essentially, this classifies the anchors as permanent-removable anchors. SBMA Ltd’s innovative anchor design followed BS8081: 2015+A2: 2018, the British Standards Institution Code of Practice for Grouted Anchors. This code of practice included the recommendation for double corrosion protection and was approved by the client’s engineers at Qatar Petroleum.
SBMA Ltd was required to supply the anchor tendons and associated accessories in addition to designing the anchors. SBMA Ltd’s certified tendon manufacturer, DeCa Srl (based in Genoa, Italy) satisfied all the pre-qualification requirements and were subsequently commissioned to manufacture and supply the tendons, anchor heads and accessories, including special galvanized protective caps. SBMA Ltd wishes to take this opportunity to thank DeCa Srl for their resolve in delivering an excellent service despite the challenges imposed by the Covid-19 pandemic.
Fortuitously SBMA Ltd has trained and supervised engineers at Bauer (Abu Dhabi), so even though the UK is currently subject to travel restrictions; supervision of the works in Qatar will be by engineers from Abu Dhabi. When required, SBMA Ltd will provide specialist input via live stream on mobile phones and attend meetings using Teams or Zoom.
The Covid-19 pandemic has profoundly affected the geotechnical engineering industry worldwide, and the business activities conducted by SBMA Ltd, Geoserve Global Ltd and AnchorTest Ltd have not escaped this. The key for all concerned is to remain positive, flexible and willing to adapt to alternative approaches to deliver consultancy services effectively.
This approach was applied recently when Dr Devon Mothersille delivered a presentation and demonstration of the AnchorTest software package. AnchorTest is a unique product designed to provide real-time analysis and Cloud-based data management, during the mandatory testing of grouted anchors installed in soil, rock or fill.
The software has proved effective in optimizing the process of anchor testing, and it is currently programmed to execute data analysis following BS8081:1989 (still used in many regions around the world), PTI DC35.1-14 and EN ISO 22477-5: 2018 (Test Method 1). Also, special custom development arrangements to create bespoke modules for specific project specifications are available. The product has been implemented successfully on anchor projects in several countries, including Australia, Russia, South Africa, Turkey, the US and the United Arab Emirates.
The original inquiry came from a ground engineering contractor based in South America following an excellent short course presented in Bolivia by AnchorTest representative Dr Antonio Marinucci. Based on this, arrangements were made for Dr Mothersille to describe, and demonstrate, the product using the ‘Zoom meeting’ video conferencing facility. Based at his office in the UK, Dr Mothersille was able to successfully communicate with attendees from five different locations in Chile and one from New York. The AnchorTest software, which uses an iPad and the iOS platform, was connected to a laptop and real-time data input, using actual load-extension anchor data, was successfully demonstrated, including full Cloud functionality.
The response from those who attended the session was very positive, and this has established a practical approach for future marketing endeavours.
Dr Mothersille conducts a demonstration of AnchorTest software to parties based in Chile and the US from his office in the UK
The serious health issues associated with Covid-19 have forced the outstanding foundation specialists Constructora Lancuyen LTDA, to temporarily withdraw from the Edificio Sangers project in Temuco, Chile. Lancuyen have successfully executed 60% of the temporary single bore multiple anchors (SBMAs) used to support a basement excavation in Temuco, which is the capital of Cautin Province and the Aruacania region in southern Chile, approximately 416 miles south of Santiago.
The foundation excavation is 45m long x 38m wide x 7m deep and is designed to accommodate a two level basement for a 18 storey building founded on 15m long, 1m diameter piles. The ground conditions are challenging, comprising soft clays with SPT N values less than 5 for depths of up to 20m. Under such conditions the use of the SBMA system provides an optimal solution by efficiently distributing the anchors loads along individual unit lengths within the fixed anchor.
Constructora Lancuyen LTDA are exclusive licensees of the SBMA system in the region, and have acquired a considerable level of expertise in executing the system in difficult ground conditions.
Constructora Lancuyen LTDA have prioritised the health and wellbeing of their dedicated workforce and will only resume work on the project once it is judged safe to do so in accordance with the government advice and company guidelines.
Overview of excavation at Temuco, Chile
Installation of temporary SBMAs with shoring planks, soldier piles and waling beams
The Corniche Towers development site comprises a foundation structure with some 406No. piles and an excavation supported by a six sided diaphragm wall comprising 65No. panels and extending to 17.75m at its deepest point. A section of the excavation is supported by 59No. anchored secant piles due to the close proximity of an adjacent existing structure and the difficulties involved in attempting to construct a diaphragm wall at this location. The excavation support system incorporates 1.067m and 1.220m diameter tubular struts at one end but generally relies on 627No. temporary ground anchors throughout, extending to up to three levels.
Due to unforeseen circumstances the design service life of the anchors had to be extended beyond the anticipated 2 years and this necessitated an inspection programme to investigate their current condition. Dr Mothersille was engaged by the Bauer International FZE to undertake the initial visual inspection and preliminary assessment.
Overview of the Corniche Towers Development site
Dr Mothersille presents interim findings to key representatives on site. From left to right: Muhammed Shahza (Foundation Property Management), Zubair Siddiqui (Foundation Property Management), Dr Devon Mothersille (Geoserve Global Ltd), Mr Vikram Thakur (Archgroup), Mr Farid Mansour (Bauer International FZE)
An early rise at 2am, a 2 hour drive to London’s Heathrow airport, a 1 hour 20 minute flight, a train journey and a taxi journey were all necessary in order for Dr Devon Mothersille to get to the CEN/TC 250/SC 7 joint working group meeting in Delft, The Netherlands on 5th December 2019. Dr Mothersille joined fourteen UK representatives and seventy other representatives from all over Europe at the NEN office in Delft.
The purpose of the meeting was initially to establish the status of the three different parts of EC7 (prEN 1997-1, -2 and -3), with particular reference to issues such as partial factors, geotechnical categories and reporting. Through presentations, questions and discussions, the aim was to highlight differences between the three parts and make some initial assessment of what further harmonization is required.
The overriding consensus amongst attendees was that the two day meeting was a success and paves the way for a productive 2020.
Dr Mothersille enjoys dinner with some European colleagues after the first day of activity
As a special guest of Aston Martin, Dr Devon Mothersille represented Single Bore Multiple Anchor Ltd, Geoserve Global Ltd and AnchorTest Ltd at a corporate event held at Red Bull’s outstanding Formula 1 facility in Milton Keynes. During a thoroughly enjoyable morning he was introduced to various Formula 1 racing cars and listened to detailed explanations on the technology and how it has evolved throughout the years.
The highlight of the visit was that Dr Mothersille was accompanied by a driving expert and was given an opportunity to drive a 2019 Aston Martin DB11 volante and a 2019 Aston Martin Vantage for several miles along country roads and on the motorway. Dr Mothersille even got a chance to see, and sit in, the Aston Martin DBX, the new SUV due to be launched later this month (no cameras permitted for this one)!
An overview of Red Bull’s Formula 1 facility in Milton Keynes showing racing cars used over recent years
Dr Mothersille poses with Red Bull’s Formula 1 racing car
Dr Mothersille about to enjoy his drive of the 2019 Aston Martin DB11 Volante
In his capacity as Lead GB Anchors Expert, Dr Mothersille attended the CEN TC250/SC7 WG3 TG5: ANCHORS meeting in Dusseldorf, Germany. In total 11 European representatives attended the meeting from eight countries; UK, France, Belgium, Netherlands, Romania, Germany , Ireland and Denmark.
During long and intensive sessions the group successfully managed to address the outstanding comments on the 3rd draft of the design standard that were not covered during a similar meeting held in Brussels in September. In addition, clauses from the standard were amended as they were discussed which amounted to a very productive session for all concerned. The revised draft is scheduled for submission at the end of October 2019.
CEN TC 250/SC7/Task Group 5 from left to right.
Ole Muller (Denmark), Eric Farell (Ireland), Noel Huybrechts (Belgium), Devon Mothersille (UK), Klaus Dietz (Germany), Eva Dornecker (Germany), Ira Gutjahr (France), Barton Admiraal (Netherlands),
John-Paul Volcke (France).
Alexandra Ene (Romania) also attended the meeting but was not present when the photograph was taken