Ground and Water News – Christmas 2019
Geoenvironmental • Geotechnical • News • Regulation
This month your problems have been piling up. The team at Ground and Water has responded, gone the extra mile, developed new services and delivered your solutions in record time. Working together we are building the future.
In this edition:
Hydrogeology Planning Conditions
WHAT’S HAPPENED HERE… !?
The side of a house collapsed during the construction of a basement under the adjacent property. Information provided by the contractor, suggested the piles (pictured in the photo) were of recent construction and complete with a capping beam. An engineer from Ground and Water was invited to visit site by a strategic partner, to gather information and examine potential causes. Discussions with on-site personnel and anecdotal evidence provided, indicated the following possible design faults:
1. The piles were supposed to be reinforced to 7.00m bgl. However, some of the piles were only reinforced to 3.5m bgl, meaning that the stiffness of the piles was reduced.
2. A capping beam was not constructed on top of the piles and therefore each pile moved independently, weakening surrounding piles, due to uneven load transfer. This led to extra stresses on surrounding piles. The failed pile was so compromised, it was not be able to withstand the anticipated load.
The contractor maintained that an extended period of dry weather, followed by heavy rainfall in September, may have displaced the piles by as much as ~0.5m. An existing property immediately to the south of the basement excavation, also placed additional load on the soil, which could have been transferred horizontally against the piles. These factors conspired, causing the soils along the southern and western face of the basement excavation to collapse, causing the wall of the adjacent property to collapse.
Ground and Water Limited’s engineer concluded that the basement collapse was most likely due to pile design faults rather than extensively poor ground conditions.
Your problems ‘pile’ up, but solutions are found
Ground and Water helping you to preserve our architectural heritage.
Ground and Water was approached by a client, who was concerned about the potential impact of piling on a listed boundary wall. Due to the proximity of the proposed piles, the reduced level dig being undertaken on one side of the wall and the shallow nature of the historic wall’s footings, it was necessary to evaluate different piling techniques and their potential impact. Read about how the issue was solved without damaging the historic wall.
Got the gear, but currently no idea
Rapid reactions and a quick turnaround allows Ground and Water to keep you building
A developer proposing a piled foundation scheme in north-west London had booked a piling rig. But as often happens, there was no Pile Mat design. The clock was ticking.
Ground and Water was contacted by the client to undertake plate load testing and Pile Mat design for a proposed piled foundation scheme. Find out how an expensive delay was averted in only four days.
Pragmatism and science, get client’s hydrogeology planning conditions SORTED
Ground and Water was approached by a client to help with a hydrogeological condition attached to a planning permission on former marshland in Portsmouth. The planning permission, related to groundwater and the potential impact of the development on groundwater levels onsite and on the nearby, Great Morass. Following two months of monitoring and the analysis of historical data, the planning conditions were satisfied. Read the full story here
New Services from Ground and Water
Cost-effective small-scale site investigations for house extensions
Sometimes builders will try to avoid carrying out a full ground investigation by asking structural engineers to visit sites to inspect small trial holes before minor extensions are built. If you are a structural engineer do you know how you can ascertain a basic bearing capacity from this visit? And does this impact on your professional indemnity?
Understanding how tight budgets are on these types of build, Ground and Water has developed small scale site investigations, which can provide valuable design information for both a more traditional spread footing design and piles. At a small cost to the client, information on volume change potential, concrete class and bearing capacity can be provided. Please e-mail [email protected] for further information.
Site Visit by Ground and Water Engineer helps move project forward
A new, time and money saving, call-out service has been launched to allay building inspector’s concerns over foundation depths.
Over recent weeks, Ground and Water has been approached six times by clients, following site visits by regulatory bodies. The regulators had requested that foundation excavations were deepened, due to the soils looking like Made Ground or due to the proximity of trees. These unexpected requests were contrary to the Ground Investigation reports and could have caused significant delay in pouring concrete, increased the volumes of waste, required more concrete and generally increased costs.
This has occurred on sites in Croydon, Woking, Uxbridge, Tonbridge, Shacklewell and Four Marks. On one of these sites the request to deepen, would have meant encountering the water table!
Ground and Water can send an engineer at short notice, to visit your site following a telephone briefing. In the cases mentioned above, the onsite engineer was sufficiently experienced, or there were sufficient systems in place, that a site decision over the footings could take place. Generally, this involved confirmation that the original design in the Ground Investigation Report was correct and that a deepening of the footings was not appropriate. This was then confirmed with the regulatory authority following the Ground and Water engineer’s site visit. Please e-mail [email protected] for further information.
New Havant soil treatment facility
Ground and Water has been informed of a new soil treatment facility that recently opened in Havant, Hampshire. It has the potential to aid developers reduce your muck away costs.
The new facility is licenced to treat 125,000 tonnes per year, of a wide variety of contaminated soils. Situated between Southampton and Chichester, the new treatment site offers a cost effective and sustainable alternative to the increasing price of landfill disposal.
Ground and Water can provide accurate and reliable waste assessment and testing and in partnership with these types of treatment facilities, can help clients identify the most efficient treatment route. For further information please contact [email protected]
People matter
Our vision and values are delivering real benefits for you.
We have welcomed a new engineer to the Ground and Water family, Aaron! Aaron’s addition to the team, means we have exactly doubled our engineering capacity over the course of two years. This means we can offer you increased service levels and as can be seen from our case reports, be there when you most need us.
Giving something back
A few more members of the team have ‘given back’ to the local community by attending Corporate Social Responsibility days – Robin and Natasha recently went to work, helping to maintain heathland habitat for sand lizards in the Farnham area (Bourne Wood). They spent the day removing pine and birchwood saplings; they got the chance to use the ‘tree popper tool’, all the while helping to protect a rare habitat.
Let it Go… !
Ground and Water’s technician, Kristoff (sorry we meant James), swapped digging for Disney and spent the day with Elsa and Anna at a local garden centre. Along with Father Christmas they entertained the masses with a few Frozen numbers. They drew a pretty big crowd, which was ‘ice to see and all proceeds were donated to the Countess Mountbatten Hospice in Southampton. We wanted to share this picture of the ‘cool’ trio with you. They said ‘Let it go’.
How our team culture makes the difference to your business
This month also saw the issue of our ‘G&W Little Book of Vision, Mission, Values and Behaviours’. This booklet outlines our cultural fit, the essence of Ground and Water and our vision of what we are creating by doing what we do. The company was built on friendship, trust, hard work and enthusiasm. Values that the organisation and its people continue to live by. Our aim is to continue to add to our incredible team by finding like-minded individuals that share those values. By communicating our expectations early in the recruitment process, we attract the right kind of candidate to fit the Ground and Water team.
Season’s Greetings
And finally, we would like to wish you, our clients, strategic partners and industry colleagues a very Merry Christmas and a Prosperous New Year. Keep on building a great future!