GeoCon offers a full Site Investigation service including Phase 1 Preliminary Site Investigation (Desk Study), Phase 2 Initial Site Investigation, Phase 3 Detailed Site Investigation, Factual & Interpretive Report, and Remediation Strategies.
Here at GeoCon we see our site investigations and ground investigations as an investment. Money spent on a good ground investigation can save money further down the line, foundations wont need to be over engineered, and large volumes of soils may not require removal or remediation.
We see our site investigations as investments and our clients do to. Statistics shows that 80% of problems encountered on construction projects are due to unforeseen ground conditions that could have been avoided if a suitable ground investigation was carried out.
Failure to commission a suitable ground investigation can cause financial costs and costs in lost time far greater than the cost of what the site investigation would have been.
Site Investigation / Ground Investigation is carried out via a combination of the following techniques;
Site Investigation Techniques
GeoCon use a selection of the above when designing any ground investigation utilising the techniques that are most suited to the purpose of the site investigation. I.e, window sampling and concrete coring to determine the shallow ground conditions at an industrial warehouse with limited or tight access entirely covered by hard standing or on a site that may have a high potential for buried services. Or cable percussion with rotary follow on at an open site which is covered by soft landscaping and there is a requirement to gain strength information from the soils beneath the site and continue into the rock to determine the presence of shallow coal mining.
These are both just examples of how we can put together a full detailed high quality ground investigation at any site no matter how difficult to gain the required results for our clients.
Site Investigation techniques are also used in the installation of Geothermal Heating systems such as rotary open hole drilling usually around 100m deep, however for the installation of ground loops drilling is performed on a much slower basis and drilling mud /foam should be utilised to encourage the holes to stay open to facilitate the installation of ground loops.
Site Investigation Processes
Samples taken during site investigations are sent for analysis to determine their chemical content and their geotechnical properties. Both soil and water can be sampled and analysed.
- Chemical Analysis
- Geotechnical Analysis
Coring through concrete hard standing up to 1.00m thick in diameters of 150mm, 200mm, 250mm and 300mm.
This leaves a neat and tidy hole for drilling casing to fit down in order to facilitate boring in areas of hard standing.
We offer various reporting options which include the following:
- Phase II Factual Report
- Phase II Interpretive Report
- Remediation and Validation Report for Cover Systems
- Validations Report for Gas Protection Systems
Trial Pitting involves the mechanical excavation of “Trial pits” using JCB 3CX excavators or similar to excavate through the shallow subsoils beneath the surface to investigate the ground conditions. Trial pitting is used to facilitate chemical and geotechnical sampling and to gain a profile of the sub surface ground conditions.
Trial Pitting can be used for purposes such as investigating contaminated land, geotechnical investigations and mine shaft location. It can also be used for the location of buried structures such as basements and former foundations via trail trenching.
Rotary drilling is used when drilling through bedrock. Rotary drilling can be carried out as open hole, wireline or rotary cored. GeoCon utilise rotary open hole techniques for site investigation, mining investigation, and geothermal drilling.
GeoCon utilise rotary cored boreholes when more detailed information is required regarding the underlying bedrock and its physical characteristics. GeoCon also use wireline techniques subjected to the individual requirements of the project and the client.
Hand Pitting can be used when a mechanical excavator would not be practical such as digging adjacent to existing buildings to gain a picture of previous foundation types.
Hand Pitting can also be used during the validation of a cover system.
Cable Percussion Drilling
Cable Percussion Drilling or Shell and Auger as it is commonly known is a technique that boasts more drilling capability than a window sampling machine. Cable Percussion Drilling can reach depths of 30.00m plus through superficial drift deposits.
Cable Percussion Rigs are used to bore through soft ground down to rock head utilising a casing system to prevent the fall in of soft materials and running sand. Cable Percussion Drilling can be done in a range of diameters which include 150mm, 200mm, 250mm, and 300mm.
This technique can be used for investigating contaminated land facilitating sampling, geotechnical investigations again facilitating sampling and in situ testing such as SPT’s, and for the installation of ground gas and ground water monitoring wells.
Environmental monitoring is carried out as part of a thorough site investigation and generally consists of the following:
- Gas Monitoring
- Groundwater Monitoring
- Surface Water Monitoring