A Phase 1 Desk Study is an important part of the site investigation process, irrespective of whether the site has been developed or not. These reports are essential for assessing the requirements of a ground investigation from both environmental and geotechnical perspectives. A well-executed desk study will help to formulate Phase 2 investigation work, targeting specific areas of contamination or identifying requirements for specific geotechnical parameters, culminating in a cost-effective and effective investigation.Ground conditions can be one of the greatest hazards to any construction project and are often the cause of large cost and time overruns. A well-designed and executed ground investigation is an essential part of the construction process and Soil Consultants have over 30 years’ experience in designing, planning and undertaking a large variety of investigations. We use the findings of the Phase 1 Desk Study to assess the best techniques which will provide the require information, taking into account the anticipated ground sequence and any identified geotechnical and environmental risks.
We offer a wide range of exploratory methods which include:
Cable percussion boreholes, including low-headroom rigs for working in basements and areas of limited access
Rotary boreholes using coring (such as GeoborS) and open-hole techniques
Dynamic sampling (window and windowless) with tracked rigs or handheld/operated equipment
In-situ testing such as Standard Penetration Testing (SPT), falling/rising head permeability testing, self-boring pressuremeter testing in boreholes
Continuous dynamic probing
Cone Penetration Testing (CPT)
Mechanically-excavated trial pits, including large-scale soakage testing to BRE365
Hand-excavated trial pits to expose existing foundations
The fieldwork and specialist testing are carried out by experienced and trusted subcontractors who have worked with us over many years. The overall investigations are controlled by our geotechnical engineers who continually monitor progress and ensure that sufficient and relevant data are obtained for the proposed development.
Our engineers will review and summarise commercially available historical maps and database reports which identify historical and present contaminative uses, flood risks, aquifer designations and groundwater vulnerability. They will also identify any site-specific risks such as chalk dissolution features, coal mining, clay desiccation, Unexploded Ordnance (UXO) and we will commission third-party reports as required to assist in the risk assessment. We will contact the relevant local authority to obtain any further information that they hold as these can often include information not included in general databases. We have carried out over 10,000 investigations in the UK and our database of reports is an invaluable source of information on the ground conditions. We will undertake a site walk-over survey which is an essential element of the desk study to identify visual risks. Our desk study report will assimilate the necessary environmental information to provide a Preliminary Risk Assessment (PRA) and an initial Conceptual Site Model (CSM). The report will also provide preliminary information and geotechnical assessment of the site and recommendations for exploratory work.
Desk Studies have the potential to save in all aspects of the planning process both in financial terms and time. Where possible the client should be encouraged to undertake a desk study to assess the site prior to specifying a Phase 2 ground investigation.
PHASE 1 DESK STUDIES