In this issue
Basic explanation of various surface geophysical methods
What is Geophysics?
Good introduction to applied geophysics from the Environmental and Engineering Geophysical Society(EEGS)
June 2004 newsletter for the near surface Geophysical Sciences (PDF)
Solution matrix for road or motorway applications
The US Federal Highways Dept has published a very useful matrix of geophysical and NDT methods for solving engineering problems during SI, construction and maintenance of road infrastructure.
WW2 bomb risk maps
Download risk maps for your region (28 regions across the UK)
Standards and Guidelines for geophysical work:
Code of practice for site investigations
Standard guide for selecting surface geophysical methods
BS 1377 Part 3:1990
Methods of test for soils for civil engineering purposes – Chemical and electrochemical tests
BS 1377 Part 9:1990
Methods of test for soils for civil engineering purposes – In-situ tests
Guidance on the geophysical testing of geomembranes for landfill engineering
Continued in next newsletter…
Copyright © 2004
Free Advice on Feasibility of Geophysics
The success of all geophysical methods relies on there being a measurable contrast between the physical properties of the target and the surrounding medium. Knowledge of the material properties likely to be associated with a target is thus essential to guide the selection of the correct method to be used and interpreting the results obtained.
The design of a survey can be aided by the use of powerful 2D and 3D forward modelling geophysical software. With information on the expected target size, depth and composition, a geophysicist can evaluate the feasibility of a particular method including likely error bars on modelled size or depth and can determine optimum survey design parameters.
Zetica offers a free geophysical advice service to its customers. Just call and discuss your project with one of our experienced geophysicists.
One-Stop Utilities Surveying
The inaccuracy and incompleteness of sub-surface utilities maps is infamous. Failing to confirm the location of underground services and other assets, such as underground storage tanks, can have serious cost and safety implications for a project. In the UK, the requirement to locate services prior to any intrusive work commencing has now been included in Health and Safety legislation.
Confirmation of the position and depth of existing utility lines during the site investigation phase also allows for the planned diversion of essential services and ensures that exploratory boreholes and trial pits can be safely positioned.
It is important to note that detectability is dependant on the burial setting and type of services being mapped. Exaggerated claims that ‘95% of all buried services will be mapped’ should be weighed against the limitations of geophysical methods in general.
Think before you excavate – call Zetica to check for underground services and gain valuable information on unrecorded in-ground obstructions and hazards such as storage tanks, foundations and basements. Click here for brochure.
Improved Pavement GPR Service
Zetica has developed an integrated high-speed ground penetrating radar (GPR) acquisition system specifically for use on roads and runways. The system combines GPS (global positioning system) and video technologies to achieve the precise data registration required for accurate calibration of the GPR results.
The heavy weight of traffic on roads and railways means that monitoring of the condition of road pavements and track ballast is essential for proactive maintenance and planning of renewals. Ground penetrating radar is particularly suited to this task. Modern digital GPR acquisition systems enable detailed mapping of changes in road pavement construction, along with ballast thickness and condition at speeds in excess of 100km/h.
In order to accurately determine layer thicknesses the velocity of the GPR signal within the materials overlying an interface need to be determined. This is normally done directly through the use of core samples but can also be derived indirectly. The effective use of core requires that the data be accurately located. Up to now the accuracy of locating GPR data has been poor resulting in uncertain calibration.
Zetica brings the accuracy of GPR surveys to within 0.5m laterally at speeds exceeding 80km/h. Click here for brochure.
Alliance with UXB International Inc.
The status quo in the UK is that there are no recognised standards governing the advice provided or service offered to mitigate ordnance risk. As a result anyone can profess to be an expert which has led to clients receiving ambiguous advice, harming the reputation of the industry.
The directors of UXB (UK) Ltd, a subsidiary of the world’s largest ordnance and explosive company UXB International Inc. and Zetica, have announced an alliance to improve the consistency and standards of ordnance and explosive contamination advice offered to customers in the UK and Europe.
Zetica’s role in mitigating unexploded ordnance risk in the UK is underpinned by a comprehensive database of known and suspected ordnance occurrences, years of research to improve detection methods and expert identification services by skilled explosive ordnance clearance operators.
Managing Director of Zetica, Asger Eriksen, added “This alliance is a natural fit between UXB International, with a global reputation for quality and safety in ordnance services, and Zetica, one of the most respected players in the UK market. We intend to build on our strengths and deliver an even better service to our customers.”
Zetica offer a popular Geological Society registered seminar, with CPD points, on the uses and abuses of geophysics. Engineers are brought up to date on the latest geophysical methods available in the market place and interesting areas of research and development. The presentation normally lasts 30 – 40 minutes and is case history-based with a 15 minute discussion session following.
Click here to email Ellen Stevens to discuss your requirements and arrange a seminar at your offices.