The CBR test is normally used for road pavement design purposes to assess the strength of the subgrade and allow an appropriate design to be made.
The test involves driving a cylindrical plunger of a defined area into the soil at a uniform rate. This requires the use of a reaction load, (usually a 4WD drive vehicle), to provide the force to the plunger and CBR press.
Chelmer utilises the latest technology for CBR testing, allowing instant results to be sent back to the operator’s hand held tablet. This information is usually processed and available the same day if necessary, or a maximum 24 hours from the test date.
In the design of shallow foundation or traffic surface, design engineers need to know the bearing capacity of soil underneath. A plate bearing test is carried out in the field to serve this purpose. Results from the test can be used as a design parameter or used to confirm the design assumption. BS 1377 Part 9: 1990 Standard.
Our CBES-50T digital load cell can assess loads up to 500kN in capacity, in conjunction with a double stage pressure pump and PD100 electronic indicator.
The modular easy setup reference beam with adjustable height is easily transportable around site speeding up the testing process.
Variable Head Tests
These tests are used to determine the permeability of the soil stratum at various levels below the ground water table:
Rising Head Test:
Pump away the water inside the casing of bored hole to a level above bottom of casing and below ground water table. When the test starts, check the pumped-down water level with a dip meter and record the time. Let the water level rises until it is stable at ground water table and accordingly check the various water levels at a fixed time interval.
Constant Head Test:
To fill water to the top of casing such that a certain water column is added on above the ground water table and record the time of test . Let the water seeps away but continuously top up with water to maintain the level at the top of casing. Record the volume of water subsequently added and the duration of testing.
Falling Head Test:
To fill water to the top of casing such that a certain water column is added on above the ground water table and record the time of test . Let the water seep away until it is stable at ground water table and accordingly check the various water levels at a fixed time interval .
Chelmer established an ‘in-house’ testing Laboratory with the intent to provide a high quality service and turnaround time of test results that is second to none and that compliments the Site Investigation service.
Following numerous requests from our existing client base, the decision was taken to form a Drainage department within Chelmer. This formation proved highly successful and we are now able to provide an extensive array of services.
Remediation and regeneration of brownfield sites is becoming a key and essential service to enable the redevelopment of sites, especially within the housing sector. Chelmer can provide investigations to assess contaminated sites and can undertake the necessary remediation works to provide an end site suitable for redevelopment.
Working with Structural Engineers, Architects, Building Developers, Consulting Engineers, Piling Contractors, Loss Adjusters, Insurance Companies, Local Authorities and Housing Associations and the Private Householder.
Chelmer Global Ltd
Unit 7 Hall Road Industrial Estate,
Hall Road, Southminster,
Essex, CM0 7DA