CIE3032 지반공학및실험 Lecture 02 subsurface exploration 13 13 CPT (Cone Penetration Test) A CPT device consists in a cylindrical probe with a cone-shaped tip with different sensors that allow a real time continuous measurement of soil strength and characteristics by pushing it into the ground at a speed of 2 cm/s. The typical CPT probe measures the stress on the tip, the sleeve friction and the pore water pressure. Some of them are equipped with a geophone in order to be able to perform shear wave velocity measurements. The data is normally read by a field computer that displays it real-time and stores it at regular depth intervals. Measurements can be taken at any intervals desired. http://www.ce.gatech.edu/~geosys/Faculty/Mayne/Research/index.html
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CPT (Cone Penetration Test)contents.kocw.net/KOCW/document/2014/hanyang/parkduhee1/... · 2016-09-09 · Cone penetration test (CPT) Originally known as the Dutch cone penetration
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A CPT device consists in a cylindrical probe with a cone-shaped tip with different sensors that allow a real time continuous measurement of soil strength and characteristics by pushing it into the ground at a speed of 2 cm/s. The typical CPT probe measures the stress on the tip, the sleeve friction and the pore water pressure. Some of them are equipped with a geophone in order to be able to perform shear wave velocity measurements.The data is normally read by a field computer that displays it real-time and stores it at regular depth intervals. Measurements can be taken at any intervals desired.
Originally known as the Dutch cone penetration test60 cone with a base area of 1000mm2 and diameter of 35.7mm attached to the lower end of a 15mm rod surrounded by a 20mm pipe. The cone is pushed 0.5 m into the ground at a rate of 1 - 2 cm/s. The pressure exerted on the rod is plotted against depth. Measures a) cone resistance (qc) and b) frictional resistance (fc)Modified CPT: Electronic cone and Mechanical cone
A Flat Dilatometer probe consists in a steel blade with a circular membrane in one of its sides. The membrane has electrical sensors which can detect its position (flexed to the inside or outside and parallel to the blade).This blade is pushed into the ground and at desired depths the membrane is inflated using any kind of compressed gas, normally nitrogen.When the probe is pushed into the ground the soil pressure makes the membrane flex to the inside of the dilatometer blade. At measurement depths the membrane is inflated and an "A" reading of pressure is obtained when the membrane reaches its initial position (parallel to the blade), and a "B" reading is obtained when the membrane displaces 1.1 mm to the outside.This parameters are used in several correlations to obtain properties of the soil, such as compressibility and soil behavior classification.