How accurate is the CPT?
Occasionally I am asked “How accurate is the CPT?” In short – generally it’s more accurate than most other in-situ and laboratory tests for a […]
Estimating Soil Permeability from CPT
Lunne et al (1997) suggested an approximate method to estimate soil permeability (hydraulic conductivity) from the CPT via the Soil Behavior Type (SBT) chart using […]
Shear Wave Velocity, Vs, from CPT
The shear wave velocity (Vs) is a very useful parameter since it links directly to the small strain shear stiffness of the soil (G0). Although […]
Settlement calculations using CPT data
Traditionally the CPT has not been used extensively for the calculation of vertical settlements due to foundations loads. Partly this has been due to the […]
Evaluation of Cyclic Softening in Clays
Boulanger and Idriss (2007, ASCE) recently presented an excellent summary for the evaluation of the cyclic softening in silts and clays. They correctly suggest that […]
Transition Zones in CPT Data
A challenge when using CPT data for liquefaction evaluation is that the CPT data are collected at very close intervals, typically ever 5cm (2 inches), […]
Shearwave Velocity for Settlement Calculations
In this ‘Remarks’, I would like to discuss the application of shear wave velocity for settlement calculations. A major advantage of the seismic Cone Penetration […]
Myths of the CPT: Its too expensive
Welcome to Robertson’s Remarks! The previous ‘Robertson’s Remarks’ covered a pet peeve of mine, that engineers/geologist often state: “The disadvantage of the CPT is that […]
Myths of the CPT: It doesn’t collect soil samples
Welcome to Robertson’s Remarks! My name is Peter Robertson and many of you may know me as an academic/researcher (c/o University of British Columbia then […]