Numerical simulations of cone penetration in cemented sandstone

Aigerim Rakhimzhanova,Yong Zhao,Yerlan Amanbek,Colin Thornton,M.A Aguirre,R Soto,L.A Pugnaloni,S Luding

doi:10.1051/epjconf/202124914010

Aigerim Rakhimzhanova, Yong Zhao + Show 6 more

Open Access

https://doi.org/10.1051/epjconf/202124914010

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Abstract

In this study, three-dimensional simulations of cone penetration tests (CPT) in cemented sandstone have been investigated using the Discrete Element Method (DEM). We generated the realistic grain size distribution of sandstone in the numerical simulations using the Ustyurt-Buzachi Sedimentary Basin samples. Numbers of numerical CPT tests at different bond strength values were performed with the penetrometer vertically moved down at a constant rate. The results of the real-world particle size distribution show that the cone penetration resistance and side friction increase with increasing depths; and with increase in bond strength the cone resistance and side friction decrease, while the friction ratio increases. The result of numerical CPT tests in cemented sandstone was found to be in good agreement with the Soil Behaviour Type (SBT) classification system from CPT data.

Highlights

The main applications of the cone penetration test (CPT) in geotechnical engineering are for classification and identification of soil types, and for stratigraphic profiling
[4] CPT tests in granular soils; 2D CPT tests under different gravity conditions [5] and 3D CPT tests in a calibration chamber [6,7,8,9,10] taking into account the particle crushing behaviour; and 3D Discrete Element Method (DEM) simulations of CPT tests in sand material [11], where authors used the up-scaled Ottawa 20-30 sand and interpreted the response of the material as coarse-grained soils using the Soil Behaviour Type (SBT) charts
The same eight different sand grain sizes and material properties [12,13] were reused for the CPT test simulations, where the grain sizes were initially selected from the Qicpic dynamics image analyzer measurements from [19] for the Ustyurt-Buzachi Sedimentary Basin

Summary

Introduction

The main applications of the cone penetration test (CPT) in geotechnical engineering are for classification and identification of soil types, and for stratigraphic profiling. We provide a brief summary of the literature relating to the cone penetration test in granular soils that has been numerically investigated using the 2D and 3D Discrete Element Method [1]: mechanisms of deep [2, 3] and inclined [4] CPT tests in granular soils (in 2D); 2D CPT tests under different gravity conditions [5] and 3D CPT tests in a calibration chamber [6,7,8,9,10] taking into account the particle crushing behaviour; and 3D DEM simulations of CPT tests in sand material [11], where authors used the up-scaled Ottawa 20-30 sand and interpreted the response of the material as coarse-grained soils using the Soil Behaviour Type (SBT) charts. The main aim of this study is to investigate threedimensional DEM simulations of cone penetration tests in weakly cemented sandstone using the real-world particle size distribution and periodic boundaries and to examine the effect of cementation bond strength. Interpretation of obtained realistic cone resistance and side friction results within the CPT based SBT classification system [14]

Numerical simulations

Particle generation and deposition

Compression and cone penetration

Numerical results

Findings

Concluding remarks