This standard is issued under the fixed designation d 6951. Test procedure different agencies follow different test procedures. In australia in 1956, scala developed a dynamic cone penetrometer dcp, based on an older swiss original, to evaluate the shear strength of the material in a pavement 2. H4202as dynamic cone penetrometer test set with sleeved drive hammer. H4202a dynamic cone penetrometer for shallow insitu tests. The test is an empirical test which gives an indication of the shear strength of.
Typically, after each hammer blow, the penetration of the cone is measured and recorded in stiffer soils, readings may be recorded after several hammer blows. Technology transfer and project implementation information. Dynamic cone penetrometer for shallow insitu tests the dynamic cone penetrometer dcp, originally developed by george sowers, uses a 15 lb steel mass falling 20 to strike an anvil to penetrate a 1. Test procedure conducting a dcp test involves raising and dropping the hammer to drive the cone on the lower shaft through the underlying pavement layers. Dotd tr 602m60296, measuring thicknesses and widths of base and subbase courses and aggregate type surface courses ii. Forexample, a dcp blow count of 30 blows per foot is about the same as a spt blow countof 10 to 12 blows per foot. Instructs you on the minnesota department of transportations methods of dcp operation, maintenance, and test results analysis 2000. In order to test the soil beneath such a material, a hole typically about 2 inches in diameter should first be cut or drilled down to the actual soil. A minimum of 1 passing test for each 1,500 ft of chemically modified soil for each twolane pavement section 215. Field testing of soil, granular soil, and coarse aggregate the procedures for determining the maximum dry density, optimum moisture content, inplace density, inplace strength, and moisture content of soils, granular soil, and coarse aggregates in the field will be as follows. Most early pavement design procedures were, however, based on the cbr method where the cbr values of the subgrade and structural layer material were used to determine the required thickness of imported material necessary. Cbr value estimation using dynamic cone penetrometer. The schematic for the dcp is shown in figure 1 source.
A minimum of one gradation test for every 2500 lft for each 2lane pavement section 4. Qms tier 2 doc atsdcp1001 qms procedure rev a date. Dcp testing is conducted according to illinois test procedure 501, in which the number of blows to achieve 150 mm 6 inches of penetration is counted. Astm d695103, standard test method for use of dynamic cone penetrometer in shallow pavement applications 2. Note that the cuttingdrilling process should do as little as possible to disturb the. A dcp is designed to penetrate soil, rather than asphalt, concrete, or other hard surfacing materials. But very conservative risk of failure minimal often excludes materials that are eminently fit for purpose test procedure is time consuming, costly and requires large sample for lab testing. Evaluation of in situ pavement layers with the dynamic. A survey stake may be used to mark each blow during test. Insitu testing, dynamic cone penetrometer, allowable bearing pressure estimation, economic testing. Cbr test procedure california bearing ratio for road design. The great value of this test is that it is comparatively easy to perform and.
Using the dynamic cone penetrometer and light weight. More expensive, automated dcp rigs can be purchased that are towable. The cbr test is one of the most commonly used methods to evaluate the strength of a sub grade soil, sub base, and base course material for design of thickness for highways and airfield pavement the california bearing ratio test is penetration test meant for the evaluation of subgrade strength of roads and pavements. The standard penetration test spt is most popular and economical test to determine the surface information, both on land and offshore. Information includes how to assemble the instrument, conduct a test, and determine test frequency and location. Pdf standard test method for use of the dynamic cone. Procedure refer to astm d 6951 section six 6 for operation of dcp. Test method t161 penetration resistance of a soil dynamic cone penetrometer 9 kg mass 1. Schematic comparison of laboratory test procedure between dcp left and cbr right. Since such predictions using the dcpt are subject to considerable uncertainty, dcpt should be performed for compaction control in combination with a few conventional test methods, such as the nuclear gage. The penetration rate may be related to in situ strength such as an estimated in situ cbr california bearing ratio. This test is widely used to obtain the bearing capacity of soil.
The dual mass dynamic cone penetrometer dcp described in this report will overcome some of the shortfalls associated with the cbr and airfield cone penetrometer. Procedure preparation for test dcp is not intended to be driven through concrete or bituminous layers. In australia in 1956, scala developed a dynamic cone penetrometer dcp, based on an older. It is a valuable method of assessing subsurface stratigraphy associated with soft materials, discontinuous lenses, organic materials peat, potentially liquefiable materials silt, sands and granule gravel, and landslides. Again, dependent upon the test apparatus, depth of testing, and the condition of the subgrade, the test requires 5 to 10 minutes to complete. The test is an empirical test which gives an indication of the shear strength of a soil. Designated traffic classes for pavement design after malawi dcp manual, 20 dn. The user manual of uk dcp explains the installation of the program and gives a detailed description of the use of the analysis software. Depending on the dcp apparatus the test can be conducted efficiently with as little as 1 to 2 people. After dcp blow counts are obtained, these must beconverted to standard penetration test spt values nvalues. The general relationshipbetween dcp blow counts and nvalues is 2. A minimum of one moisture test for every 4h of lime soils mixing construction traffic is allowed after the minimum dcp blow count is obtained and shall be. Dynamic cone penetration test pavement interactive.
Can one use the dynamic cone penetrometer to predict the. Introduction to the dcp design method for low volume. The dynamic cone penetrometer dcp is a simple, cheap and effective. The dynamic cone penetrometer dcp test was developed by transport and road research laboratory trrl, england. Follow the below mentioned step by step procedure to calculate cbr value using dcpt result. Pa igegreen apply ing the dynam ic cone penetrometer des ign method to low volume roads. Application of test the dcp is used as a rapid means of assessing the sequence, thickness and insitu bearing capacity of the unbound layers and underlying subgrade that comprise the pavement structure. Illinois test procedures for other materials may be included. Standard penetration test spt of soil procedure, tools. Record the initial reading on the dynamic cone penetrometer scale. The usace standard dcp typically requires two people to efficiently operate the device, an. A minimum of one passing dcp test for each lft for each 2lane pavement section 3. To get a clear understanding of the calculation, an example is also given at the end of the procedure.
Astm d6951 d6951m 18 standard test method for use of. The engineers perform the testing insitu to give an estimation of the load bearing capacity which a soil can withstand, by measuring the extent of penetration into the ground of. Alternatively, the depth of penetration may be measured after each blow when extremely soft materials are encountered. Dynamic cone penetrometer dcp test and the california bearing ratio cbr test.
The dynamic cone penetration test for soil resistance. If you intend to test beneath these surfaces a core hole at least 50mm in diameter must be made. Applications for the panda instrumented variable energy dynamic cone penetrometer from sol solution include archeology, cable and pipe laying, trench work, flexible pavements, backfill, unsealed roads and mine haul roads, landfill facilities, tunnels e. Astm adopted the cpt procedure as test d3441 in 1974. The apparatus consists of 16mm diameter steel rod in which a tempered steel cone.
Most of these problems are discussed in the following articles. Baseline references on the spt procedure many of the spt correlations have been explored, and there exist no small number of problems, requiring considerable judgment. Dcp test set with sleeved drive hammer for safer operation. The dynamic cone penetrometer dcp is a simple device for m easuring the stiffness of unbound materials. Prediction of cbr using dcp for local subgrade materials. Army engineer research and development center erdc recommends the test procedure described herein. Standard soaked cbr is strength test most used for materials selection for all pavement layers tried, trusted and understood. These can be used to anchor or calibrate the dcpt correlation for specific sites, reducing the uncertainty in the. Dcp index mmblow 7 cbr % 8 moisture % 1 number of hammer blows between test readings 2 cumulative penetration after each set of hammer blows 3 difference in cumulative penetration 2 between readings 4 3 divided by 1 5 enter 1 for 8kg 17. Scope this test method sets out the procedure for determining the resistance of natural ground and earthworks to penetration by the dynamic cone penetrometer with a 9 kg mass. General a the dynamic cone penetrometer provides a means of. Astm d6951 d6951m 09 standard test method for use of. Dcp testing is used to determine the strength of the subsurface and design load of the soil.
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