The Identification of the Uncertainty in Soil Strength Parameters Based on CPTu Measurements and Random Fields

Abstract

The present paper responds to the challenge of modeling uncertainty in soil strength parameters concerning its spatial variability in a situation of limited soil information. Understanding this uncertainty allows for the management of the risk of geotechnical structure failure. In the present work, this uncertainty is identified based on signals from the cone penetration test (CPT) device. Signals are directly transformed using existing interpretation methods (typically used as a source of mean values of parameters for a given range of depths) to obtain depth-varying effective strength parameters of the soil. The process is performed by incorporating data from two case studies from different locations in similar soil materials. First, Keswick clay from Australia, for which the results of both CPT and laboratory tests are available, is examined. Second, to further verify the obtained results, the soil from Poland called Świerzna clay, for which only CPT signals were available, is also tested. As shown, the variability of the transformed signals can be a good source of information for identifying uncertainty in soil strength. It agrees well with literature data and can be used to identify random fields describing soil parameters.

Evaluation of Creep Behavior of Soft Soils by Utilizing Multisensor Data Combined with Machine Learning

“…The method relies on pushing a specially designed probe into the soil, Figure 6b, at a relatively fast rate (20 mm/s), thus enabling continuous recording of the cone tip resistance (q c ) and sleeve resistance (f s ), as well the groundwater pore pressure (u). Despite the standardized external geometry of the cone, the measurement and transmission system used can vary considerably from one device to another [59]. By utilizing raw CPT collected data, soil layers can be identified using one of the classification procedures, such as [60], as well to provide estimates of its in situ physical and mechanical properties, such as undrained strength, compression modulus, friction angle, and unit weight.…”

Estimation of the Random Intensity of the Soil Tillage Draft Forces in the Supports of the Working Bodies of a Cultivator

“…Under the name of spatial variability, the random nature of some soil properties is also studied and evaluated (Delhome, J.P., 1979; ISSMGE-TC304, 2021; Mashalaba L., et al, 2020). Interesting study examples for spatial variability are presented in (Jurado C. S., et al, 2012;Tekeste M., et al, 2005;Uzielli M., et al, 2005), and (Pieczyṅska- Kozlowska J., et al, 2021;Lu H., et al, 2022;Salgado R., et al, 2015;Zhang W., et al, 2015) for a property used in the characterization of soil resistance, namely the cone penetrometer test. A large number of works describe the variability of the tensile strength of agricultural machines intended for soil processing (Al_Neema K.A., et al, 2021;Al-Kheer A.Al-K.A., et al, 2011;Markinos A.).…”

Design of Cone Penetration Test Data Relay Transmission by Magnetic Communication

“…Cone penetration test (CPT) refers to a process that drives the probe with sensors into the soil through moderate and stable pressure at a constant speed as far as possible and measures the stress from the probe tip and the friction from the side wall in this process. After analyzing the stress from the probe at different depths by means of statistics, we can infer the properties of a soil layer [1][2][3]. CPT is characterized by a lower cost but higher reliability.…”