California Bearing Ratio
Good construction depends on the quality of the ground being built on. Getting that ground geotechnically tested, to make sure it’s suitable for the purpose it’s been earmarked for, is just good common sense. At Perry Testing Ltd, our in-situ ground surveys can aid in the ground investigation, allowing our clients to build with confidence. Many tests can be done without the need for downtime, keeping projects on track and on budget. And reports for many of the services we have on offer can be issued immediately, considerably reducing the wait times on vital reports.
In brief, we offer:
- California Bearing Ration penetration testing for evaluation of the natural ground, subgrades and base courses.
- Incremental Plate Load testing to give you an accurate measurement of what weight a material can safely bear.
- Dynamic Cone Penetration to establish the condition of pavements and soil.
- Hand Shear Vane which calculates the undrained shear strength of cohesive soils.
- Sand Replacement Density testing to evaluate the density of natural soils so compaction can be carried out accurately.
- Core Cutter Density which offers the same level of testing as Sand Replacement, but for solids such as clays.
Further descriptions of the services offered by Perry Testing Ltd are detailed below. Please do contact us if you have any questions or queries. We have a team of highly experienced, friendly, engineers on hand to help.
Incremental Plate Load Tests
We carry out incremental plate load tests on an array of materials to prove their load bearing capabilities. The incremental plate load test is described in BS 1377: Soils for civil engineering purposes. They are often used to prove pile and crane mats prior to the plant arriving on site to ensure safety. The test is performed with site plant as kentledge, typically a 13T tracked excavator. The design/safe working load is applied to the plate in equal increments and the deformation recorded. We can issue reports instantly to avoid delays.
Dynamic Cone Penetrometer (DCP).
We use the Dynamic Core Penetrometer to obtain an indicative CBR value without the need for costly downtime of any site plant. We often use the DCP to measure road and pavement condition and stiffness. We also use the hand-held device to measure the strength of in-situ soil and to determine the thickness and location of underlying soil layers.
Hand Shear Vane
We will use a hand-held instrument to determine the undrained shear strength of cohesive soils. The result can be given in Kn/M² or it can be given as a vane shear strength using the calculation given in BS 1377. Either of these results can be provided instantly on site by our knowledgeable engineers.
Sand Replacement Density (SRD)
We perform Sand Replacement Density tests to measure the in-situ density of natural soils or imported materials using sand pouring cylinders. The in-situ density is normally used for highway or pavement design purposes to give the Degree of Compaction (required for highway and site specifications). This allows our customers to be confident in the compaction of the material before proceeding with final layers. The test method is described in BS 1377: Soils for civil engineering purposes: Part 9. The SRD test is an efficient and accurate way of accessing the density of most materials. Unlike other methods there is no need for time consuming and expensive calibration of equipment for every site and material type.
Core Cutter Density
We use the core cutter for the same purpose as the Sand Replacement Density but it is used solely for cohesive materials (eg. clay). Again, this is an extremely effective way of quickly and accurately checking compaction on site. The samples can then also be used for further tests such as triaxial or permeability tests.