When doing a CPT test a steel tube with an outer diameter of 36 mm is pushed statically into the ground with a penetration speed of 20 mm per second. Initial parts of dissipation curves for U 2 and NC specimens. The addition of pore water pressure measurements allows for a more reliable determination of soil stratification and soil type than standard CPT cone tip and sleeve resistance only. Investigators may obtain soil samples from adjacent borings for correlation purposes, but prior information or experience in the same area may preclude the need for borings Geo-characterization and properties of natural soils by in situ tests. In this research, the influence of penetration rate, filter element location, and effective vertical stress also expressed as OCR in this research on excess pore water pressure, and dissipation of excess pore water pressure measured during dissipation tests, and cone resistance were investigated. It is beyond the scope of this practice to discuss all of these methods in detail.
Cone Penetration Testing
An acknowledged specialist in CPT, Lankelma also offers a worldwide consultancy and training service. Because of this the parasitic friction on the sleeve especially in sands was eliminated. In that sense, the importance of location of the filter element for measuring pore water pressure needs to be emphasized again. Canadian Geotechnical Journal , , 53 8: The instantaneous initial excess pore water pressures were used to normalize the excess pore water pressure data as in Figures 5 and 6.
In-Situ Soil Testing | Piezocone | Dissipation test
Subscribe to Email Updates. As a special feature, a high-speed digital oscilloscope was used to measure the instantaneous rapid change i. The slurry consolidometer was designed and used to prepare large cohesive specimen, mm in inside diameter and mm in height Kurup , Voyiadjis et al. Begemann published graphs enabling to deduce the frictional load capacity for different sorts of piles from the measured local friction resistance. Pile driving in clay slopes. The difference of the excess pore water pressures of U tip and U 2 configurations at a specified penetration rate was greater for over-consolidated specimen than for normally consolidated specimen. It was also found that comparing 0.
During penetration internal load sensors measure cone resistance and sleeve friction, every 2 cm. Their method uses a seismic piezocone to measure the soil stiffness using down-hole shear wave velocity measurements. Soil samples are not obtained. By dividing this value by the cone surface, the cone resistance stress was obtained. This could result in a strange situation that, under extreme circumstances, the factual penetration depth appeared to be many meters less than the sloping penetration length. For environmental site characterization applications, the electronic piezocone also has the additional advantage of not generating contaminated cuttings that may present other disposal problems 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ,