DCP Description
Our Army Corps of Engineers Dynamic Cone Penetrometer (DCP) consists of a steel extension shaft assembly with a 60 degree hardened cone tip attached to one end. The cone tip is driven into the pavement or sub grade by means of a sliding dual mass hammer. The diameter at the base of the cone is 20 millimeters. The diameter of the cone is 8 millimeters larger than that of the extension shaft assembly to ensure that the resistance to penetration is excerpted on the cone.
Operation
The DCP is driven into the soil by dropping either the 8 kg or 4.6 kg sliding hammer from a height of 575 millimeters. The 8 kg hammer is converted to a 4.6 kg hammer by removing the hexagonal set screw and removing the outer sleeve from the dual mass hammer. This procedure can be accomplished during a test, since the outer sleeve is designed to slide over the DCP handle.
The cone penetration caused by one blow of the 8 kg hammer is essentially twice that caused by one blow of the 4.6 kg hammer. As a result, the 4.6 kg hammer is more suitable for use and yields better test results in weaker soils having CRB of 10% or less. It can also be used for evaluating soils in foundations for residential structures which require bearing value of 2000 PSF (approximate CBR of 6%). The 8 kg hammer is preferable for high-strength soils, which it penetrates more quickly than the 4.6 kg hammer. However, the 4.6 kg hammer can be used on soils up to CBR 80%.
About Salem tool
Salem Tool Company was founded by Leonard Bourgoin in 1983 in Northville, Michigan. Over the years, the company earned a reputation for excellence in manufacturing high-precision, high quality machined products. Some 20 years ago, Leonard was approached by a local engineering firm that was experiencing problems with a dynamic cone penetrometer (DCP) manufactured by a company out of state. The firm was hoping that Leonard could help resolve issues with the penetrometer, including frequent breakage and parts wearing out prematurely. Please visit http://www.salemtool.com/ to know more about the products produced by salem tool.
