Need an Geotechnical Survey?
Use RenKap
Simply upload your site on the RenKap platform to:
- Reduce your management time by 90%
- Instantly receive a minimum of 3 quotes from our vetted suppliers
- Receive one digital dashboard with survey recommendations
- Quality reports every time guaranteed
Need a Geotechnical Survey?
Use RenKap
Simply upload your site on the RenKap platform to:
- Access the best vetted surveyors
- Instantly receive a minimum of 3 quotes from our suppliers
- Receive one digital dashboard with survey recommendations
- Quality reports every time guaranteed
The only site investigation checklist you need
Download our site investigation checklist, which covers the 13 site investigation surveys you need to complete on every site. This includes a rundown of why you need each of them and at what stage throughout the project lifecycle.
What is a geotechnical survey?
A geotechnical survey is an investigation of the physical properties of the soil and rock on a particular site. This survey is typically conducted by a geotechnical engineer or engineering geologist, and it is used to gather information about the soil and rock layers that are present on the site, as well as the subsurface water conditions. The goal of a geotechnical survey is to provide information that can be used to design and construct foundations, slopes, embankments, and other structures that are built on the site.
Why do you need a geotechnical survey?
Geotechnical surveys are extremely important as the information gathered during the survey will be used to design the foundations and other key structural components of the development, such as slopes and embankments. Additionally, geotechnical surveys can also be used to identify potential hazards or issues that may arise during construction, such as sinkholes or unstable soil conditions. By identifying these issues early on, engineers can design and construct the structure in a way that minimises the risk of failure or collapse.
When is a geotechnical survey required?
Geotechnical surveys are typically required for new construction projects, but they can also be conducted for existing structures if there are concerns about the stability or safety of the structure. For example, if an existing building has been damaged in an earthquake, subsidence or other, a geotechnical survey may be conducted to assess the damage and determine if the structure is safe to occupy.
Geotechnical survey is required at the early stage of a development before the foundations are designed as the outcomes of the survey will determine the foundations required.
How long does a geotechnical survey take?
The time it takes will depend on the size of the site and the amount of boreholes required on that specific site. Typically at RenKap our surveyors can complete the geotechnical surveys within 6 weeks.
What is the risk of not completing the geotechnical survey?
If a geotechnical survey is not conducted, the risk of failure or collapse of a structure can be much higher. The soil and rock layers on a site can vary greatly, and if the wrong type of foundation is used, or if the structure is not designed properly to account for the subsurface conditions, it can lead to serious problems. For example, a building constructed with inadequate foundations on unstable soil can sink or shift, causing damage to the structure and making it unsafe for occupancy. Additionally, failure to identify potential hazards, such as sinkholes or unstable soil conditions, can also lead to serious problems during construction.
Progressing a scheme without having an understanding of the ground conditions could result in the scheme not passing planning, fines and potentially imprisonment if it results in injury or death.
How is a geotechnical survey completed?
The process of completing a geotechnical survey typically involves several steps:
- Site reconnaissance and agree the scope: The first step is to review the site including information about the location and layout of the site, as well as the surrounding area and the development proposals. This will then allow the client’s engineers or the supplier to suggest the scope required for the Geotechnical survey. This will include the quantity of boreholes required, their depths and locations. Additionally ground and gas water monitoring may be required and trial pits may be required which allow the supplier to test the infiltration rate of the site.
- Geotechnical sampling: The next step is to collect samples of the soil and rock layers that are present on the site. This is typically done by drilling boreholes into the ground and taking core samples of the soil and rock layers. The samples are then analysed in a laboratory to determine their strength and characteristics.
- Additional tests: At this stage the surveyor may also conduct ground and gas water monitoring in the boreholes that were already drilled. Also they will dig trial pits which will be filled with water to see how long it takes for the soil to infiltrate the water. This will determine if natural soakaways will be possible on the site.
- Analysis and interpretation: The data collected during the survey is then analyzed and interpreted by a geotechnical engineer into an interpretive report. Structural engineers can then use this information to design the adequate foundations for the scheme.
What are the key pieces of information that suppliers need from a client to complete a geotechnical survey?
The key pieces of information would include:
- Site location
- Redline boundary (the perimeter of the site boundary)
- Site access instructions
- A scope of survey (i.e. a brief of exactly what they need to include)
- Development Proposals
- Unencumbered access to the site
What are the key items that would affect the cost of a Geotechnical survey?
The key factors that would affect the cost of the survey would include the size of the site, location of the site, scope of works required i.e. the number and depth of boreholes, if trial pits are required and if ground and gas monitoring is required.
How to identify competent geotechnical suppliers?
As a minimum they should:
- Abide by the construction, Design and Management Regulations 2015 (CDM 2015)
- Abide by the Health and Safety at Work Act 1974
- Abide by HSG47 – Avoiding Dangers from Underground Services
- Have an appropriate level of professional indemnity insurance (Ideally more than £5m)
- Have an internal quality assurance procedure
- Have suitably trained and quality staff
The RenKap platform has already pre-vetted the best UK suppliers so you don’t have to.
The only site investigation checklist you need
Download our site investigation checklist, which covers the 13 site investigation surveys you need to complete on every site. This includes a rundown of why you need each of them and at what stage throughout the project lifecycle.