Our independent sister company ETS Earthworks & Stabilisation offers a full in-house earthworks, stabilisation and ground improvement service to its clients. From receipt of existing and proposed levels in DWG format, ETS assesses the commercial viability of altering the earthworks scope by way of stabilisation, typically reducing excavation, the carting of materials off site and the stone capping. Once it is deemed suitable ETS will review the provided SI report and also undertake sampling from site to ascertain the required lime or cement ratio needed to effectively stabilise and improve the existing ground. Multiple tests are undertaken and a procedure plan is put together for our clients by a fully supported laboratory with professional indemnity (PI) insurance.

 

Lime/Cement Stabilisation

In-situ soil stabilisation is used commonly in ground works and civil engineering projects. It is usually a quick and cost effective method to modify existing soils with lime and cement to create a suitable sub base platform. Most cohesive and granular sub soils can be stabilised. By altering the makeup of the sub base construction, the client will usually save time and money by removing the need to cart materials off site, but also the stone platform required can be as little as 75mm (typically 100mm) thus removing extensive sub bases and capping layers.

 

There is an extensive testing regime to ensure the suitability of the ground improvement by lime/cement. The stabilisation process is followed by strict procedures and regular site testing is undertaken to ensure it is achieving the required strength parameters. To date, most clients have preferred this approach due to the speed of application as well as the savings offered.

 

ETS’s Commitment

 

By undertaking all earthworks, stabilisation and testing, ETS retains full responsibility from start to finish.  They are then able to work alongside their independent sister company ETG Civil Engineering who in turn carry out all groundwork and civils works after the ground improvement process is complete.  This avoids any cross-over issues with other companies. 

If all relevant information is available at tender stage then ETS & ETG will commit to lump sum or re-measurement of earthworks, stabilisation and the ground works – again giving the main contractor complete confidence and cost security as well as potentially huge cost savings.  

 

Laboratory & Site Compliance Testing

 

Prior to beginning any stabilisation works ETS will carry out a robust sampling exercise across the entire site in accordance with in-house sampling plans.  These samples are then used to perform a range of tests in order to ascertain the initial material properties, the suitability of the soil for stabilisation and if appropriate, any required cement/lime additions to ensure effective performance of the ground following stabilisation.  Testing can include, but may not be limited to:

 

Material Properties

• BS 1377 Part 4 : 1990 : clause  3 – Determination of Dry Density /Moisture Content Relationship (Compaction/MDD/OMC)

• BS 1377 Part 4 : 1990 : clause  7 – California bearing Ratio (CBR)

• BS 1377 Part 4 : 1990 : Clause 5 – Determination of the Moisture Condition Value (MCV)

• BS 1377 Part 2 : 1990 : clause 3 – Determination of Moisture Content

• BS 1377 Part 2 : 1990 : clause 4&5 – Determination of the Liquid Limit, Plastic Limit & Plasticity Index (LL/PL / Atterberg Limits)

• BS 1377 Part 2 : 1990 : clause 8 – Determination of particle Density (PD/SG)

• BS 1377 Part 2 : 1990 : clause 9 – Determination of Particle Size Distribution (PSD/Grading)

• BS 812: Part 124 : 2009 – Frost Heave of Unbound or Hydraulically Bound Aggregates

• BS EN 13286-47 : 2012 - Unbound and hydraulically bound mixtures. Test method for the determination of California bearing ratio, immediate bearing index and linear swelling

 

Chemical properties

• BS 1377 Part 3 : 1990 – Organic Matter Content

• TRL Report 447 : Test No. 1 – Water Soluble Sulfates

• TRL Report 447 : Test No.2 & 4 – Oxidisable Sulfides

• TRL Report 447 : Test No.4 – Total Potential Sulfates

 

All time critical tests will be undertaken in-house by staff who have a wealth of experience in geotechnical and materials testing. This ensures that there are no unnecessary delays in receiving test results from external laboratories, and therefore in starting the stabilisation works. 

 

Once the works have begun, ETS ensure that their on-site workmanship is of the highest standard by ensuring compliance testing is performed throughout the project.  Testing can include, but may not be limited to:

• BS 1377 Part 9 : 1990 : clause 2 – In-situ density tests (Nukes, core cutter or sand replacement)

• BS 1377 Part 9 : 1990 : clause 4.1 in conjunction with IAR73 06 Rev 1 – Draft HD25 (2009) – CBR equivalent via the Plate Bearing Method

• Hand Shear Vane

• BS 1377 Part 9 : 1990 : clause 4.1 - Determination of the vertical deformation and strength characteristics of soil by the plate loading test.

 

Once all laboratory and site testing is completed, we will compile all the test reports into one clear, concise report. Included will be suitable site plans & diagrams to assist with interpretation and pinpointing test locations.  On top of all this, our experienced technical team are always on hand, so you can just give us a call to discuss any technical queries you may have.