Geotechnical Services
Ground Investigation and Engineering Support Across the UK
Geotechnical Services — Ground Investigation and Engineering Support Across the UK
Every building, road, retaining wall, and piece of civil infrastructure depends on the ground for its stability and performance. The engineering behaviour of the ground, its strength, stiffness, permeability, and variability, determines the type and size of foundations required, the stability of slopes and excavations, the design of drainage systems, and the risk of differential settlement, heave, or ground movement during and after construction. Understanding the ground beneath a development site is not an optional step in the design process, it is a fundamental prerequisite for safe, economic, and technically compliant design.
Stansted Environmental Services Ltd provides specialist geotechnical and geo-environmental investigation services for development, infrastructure, and remediation projects across the United Kingdom. Working in close conjunction with our contaminated land and environmental consultancy teams, we offer a fully integrated approach to ground investigation that combines geotechnical and environmental data collection within a single site visit programme, maximising the value of the investigation and minimising the number of separate site attendances required. We are affiliated with the Association of Geotechnical and Geoenvironmental Specialists (AGS) and operate to the highest professional and technical standards in the field.
Services
Geotechnical Services Overview
A complete range of geotechnical investigation and engineering support services designed to help assess ground conditions, manage risk, and support safe, compliant development.
Ground Investigation Methods
A range of ground investigation techniques suited to different ground conditions, investigation objectives, and site access constraints.
Laboratory Testing
Samples recovered during ground investigation are submitted to UKAS-accredited geotechnical testing laboratories for soil and rock testing.
Geotechnical Reporting
Factual and interpretive reports are prepared to provide borehole logs, trial pit logs, laboratory data, groundwater records, and engineering parameters.
Foundation Design Support
Geotechnical design support for shallow foundations, piled foundations, bearing pressures, settlement assessment, and Eurocode 7 design reporting.
Soakaway Testing
Soakaway testing carried out in accordance with BRE Digest 365 to support infiltration drainage design and planning submissions.
Dynamic Cone Penetration Testing
TRL DCP testing is used to assess in-situ soil and unbound pavement strength, especially for road foundations and pavement layers.
Radon Risk Assessment
Radon risk assessments measure soil-gas radon using in-ground detectors and confirm whether radon protection is required.
Cost Guidance
Ground investigation costs vary depending on scope, site access, ground conditions, depth, and number of investigation points required.
Why Is Geotechnical Investigation Required?
Geotechnical investigation is required for any project where structures or earthworks will be constructed in or on the ground, and where the engineering properties of the ground are not already known with sufficient reliability to support the design. In practice, this means that virtually all new development requires some form of ground investigation, from a simple trial pit investigation for a single house extension to a comprehensive borehole and laboratory testing programme for a major infrastructure project.
The consequences of proceeding without adequate geotechnical information can be severe and expensive. Foundations designed without reliable data on the bearing capacity and compressibility of the ground may be over-designed (wasting money), or under-designed resulting in differential settlement, structural cracking, and expensive remediation. Retaining walls and basement structures designed without knowledge of the groundwater regime may be subject to unexpected hydrostatic loading. Earthworks constructed without understanding the stability of the underlying soils may fail, causing delays and safety incidents. The cost of a geotechnical investigation is a small fraction of the total development cost and a very small fraction of the cost of getting it wrong.
Ground Investigation Methods
SES employs a range of ground investigation techniques suited to different ground conditions, investigation objectives, and site access constraints.
01.
Cable percussion boring
Soil investigations ke liye commonly used method. Is se borehole depth ka continuous ground record milta hai, samples recover hote hain, aur piezometers / gas monitoring wells install kiye ja sakte hain.
02.
Rotary coring
Hard soils, weak rocks ya strong rocks ke detailed information ke liye use hota hai. Is me intact cylindrical core samples recover kiye jate hain.
03.
Dynamic sampling
Driven ya pushed sampling tubes ke through rapid aur cost-effective shallow investigation method. Usually shallow soil layers ke liye, up to 6m bgl.
04.
Trial pitting
Mechanical excavator se near-surface ground conditions check karne ke liye. Usually 3–4 metres depth tak cost-effective method hota hai.
Laboratory Testing and Geotechnical Reporting
Samples recovered during ground investigation are submitted to UKAS-accredited geotechnical testing laboratories for a programme of tests designed to characterise the engineering properties of the soils and rocks encountered. Standard laboratory tests include particle size distribution, Atterberg limits, moisture content, bulk density, and organic content for classification and description. Shear strength tests, unconsolidated undrained triaxial compression, consolidated drained triaxial compression, and residual shear box. provide the strength parameters needed for bearing capacity and slope stability calculations. Oedometer consolidation tests provide the compressibility parameters needed for settlement calculations. Permeability tests provide the hydraulic conductivity data needed for drainage and dewatering design.
The laboratory test results are interpreted by our geotechnical engineers and presented in a factual report that includes borehole and trial pit logs, laboratory test data, and groundwater monitoring records, together with a geotechnical interpretive report that translates the raw data into engineering parameters and ground model sections suitable for use by structural and civil engineers in foundation design, earthworks specification, and drainage design. Our reports follow the AGS digital data format standard for geotechnical data, which facilitates data sharing with the wider design team and reduces the risk of transcription errors.
SES are a multi-disciplined environmental consultancy with a proven track record of providing high quality.
Foundation Design Support
SES provides geotechnical design support to the structural and civil engineering teams responsible for foundation design on development projects. Our services include the derivation of allowable bearing pressures and settlements for shallow spread and pad foundations, the assessment of driven or bored pile design parameters for deep foundation schemes, advice on the relative merits of different foundation types in the specific ground conditions encountered, and the preparation of geotechnical design reports in accordance with Eurocode 7 that can be used directly by the structural engineer in their design calculations.
For projects where ground conditions are challenging, expansive or shrinkable clays, made ground of variable composition and thickness, areas subject to mining subsidence, or sites with a complex stratigraphy that creates differential settlement risks, our geotechnical engineers can provide more detailed foundation engineering design advice, including the assessment of heave risk for below-ground structures in swelling clays, the design of ground improvement measures such as vibro-compaction or dynamic compaction, and the specification of flexible or articulated foundation systems that can accommodate ground movement.
Soakaway Testing and Surface Water Drainage Design
Planning policy increasingly requires that surface water from new development is managed on site using sustainable drainage systems rather than being discharged to the public sewer. Where soakaways or infiltration drainage are proposed, reliable data on the permeability of the underlying soils is essential to demonstrate that the drainage design will perform as intended and to satisfy the requirements of the lead local flood authority and the planning authority. SES carries out soakaway testing in accordance with BRE Digest 365, using test pits of the dimensions and depth specified by the standard to measure the effective infiltration rate at the depths at which the drainage system will be installed.
The results of soakaway testing allow the drainage engineer to design the soakaway system with confidence, and provide the quantitative evidence required to support the drainage strategy submitted with the planning application. Where soakaway testing indicates that the underlying soils are too impermeable to support infiltration drainage — a common finding in clay-rich soils — we provide a clearly documented test report that allows the drainage engineer to demonstrate to the planning authority and the LLFA that alternative drainage solutions are required.
Dynamic Cone Penetration Testing
The TRL DCP is a Dynamic Cone Penetrometer developed by the UK’s Transport Research Laboratory. It’s a hand‑held, hammer‑driven device used to measure in‑situ soil and unbound pavement strength by recording how far a cone penetrates the ground with each hammer blow. It is used to quickly assess the in‑situ strength and thickness of unbound pavement and soil layers, especially for road foundations. It measures penetration per hammer blow, which can be correlated to CBR and used to identify weak layers and layer boundaries.
Radon Risk Assessment
A radon risk assessment explains whether the soil beneath a site is generating enough radon to pose a realistic risk of indoor accumulation. Soil‑gas radon is measured using detectors placed in shallow ground, analysed by an accredited laboratory, and interpreted with reference to BR211 and the mapped UKHSA/BGS radon potential for the area. The measured concentration indicates the strength of the radon source beneath the site and whether radon could enter future buildings without mitigation. The assessment then states whether radon protection is required and confirms that the proposed development will incorporate the appropriate measures to prevent elevated indoor radon levels. The cost for a Radon Risk Assessment starts from £1800 plus VAT, which includes the use of a minimum of three in‑ground radon detectors.
How Much Do Geotechnical Services Cost?
The cost of geotechnical investigation varies widely depending on the investigation scope, the ground conditions, the site access, and the depth and number of investigation points required. As a general guide, Costs for a ground investigation programme for a small residential development, typically start from around £2,500 plus VAT. Larger programmes for commercial or infrastructure projects are priced according to the scope agreed with the client. Please contact us for a project-specific quotation.
Contact Our Geotechnical Team
Call SES. Please provide the site address, the proposed development type, the site area, and any existing ground investigation data or reports, and we will advise on the appropriate investigation scope and provide a detailed, fixed-price quotation within a few days of enquiry.
