Seasonal influence on cone penetration test: An unsaturated soil site example

Giacheti, Heraldo Luiz; Bezerra, Renan Cravera; Rocha, Breno Padovezi; Rodrigues, Roger Augusto

doi:10.1016/j.jrmge.2018.10.005

Cited by 25 publications

(27 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“… The appearance characteristics of land points and test sample 34 . ( a ) Land points; ( b ) field soil samples; ( c ) test sample; ( d ) soil sample in experiment.…”

Section: Methodsmentioning

confidence: 99%

Experimental study on the mechanical properties of Guiyang red clay considering the meso micro damage mechanism and stress path

Zhang

Zuo

et al. 2020

Sci Rep

View full text Add to dashboard Cite

This study investigated the macroscopic physical and mechanical properties of Guiyang red clay during surcharge loading, lateral excavation and lateral unloading with axial loading, and clarified the failure mechanism of microstructure before and after shear under different stress paths of CTC, RTC and TC. Consolidated undrained triaxial shear permeability, SEM scanning, XRF fluorescence spectrum analysis and XRD diffraction tests were conducted to simulate the actual engineering conditions. The stress–strain curve, shear strength, pore water pressure variation rule and macroscopic failure mode of soil samples under different stress paths were analysed. In addition, Image Pro Plus 6.0 and PCAS were used to study the relationship between the macro mechanical properties and micro microstructure failure under different stress paths. The stress–strain curves from CTC, RTC and TC in CU tests were different, with the peak values of shear stress under the three stress paths being P-increasing, equal P-path and P-decreasing path. Moreover, the internal friction angle and cohesion of the increasing P path were higher than those of equal P path and decreasing P path, hence, the influence of stress paths on the cohesion is greater than that of internal friction angle. The pore water pressure is strongly dependent on the stress path, and the variation characteristics of pore water pressure are consistent with the change in the law of the stress–strain curve. Under the same confining pressure in the P-increasing path, the shear failure zone runs through the whole soil sample, and the shear failure zone is significant, whereas under the condition of the P-reducing path, the shear failure angle of soil sample is about 65°, 55° and 45°, and in the equal P path, the soil sample is dominated by the confining pressure, with no obvious microcrack on the surface of the soil sample. The difference is that the distribution of pores in the path of increasing P and equal P is directional, and the anisotropy rate is small, while the distribution of pores in soil samples with shear failure and before shear is random and the anisotropy rate is high.

show abstract

“… The appearance characteristics of land points and test sample 34 . ( a ) Land points; ( b ) field soil samples; ( c ) test sample; ( d ) soil sample in experiment.…”

Section: Methodsmentioning

confidence: 99%

Experimental study on the mechanical properties of Guiyang red clay considering the meso micro damage mechanism and stress path

Zhang

Zuo

et al. 2020

Sci Rep

View full text Add to dashboard Cite

show abstract

“…Therefore, relative densities were back‐calculated from the tip resistance and mean effective stress measurements using the empirical equation of Yang and Russell 46 (see Table 2). The results for the unsaturated São Paulo sand were derived from the field CPT tests carried out in a tropical site located at the São Paulo State University 51 . In these tests, elastic shear moduli and friction angles reported by Giacheti et al 51 .…”

Section: Numerical Model Verificationmentioning

confidence: 99%

“…They also proposed a new methodology to determine the effective stress in unsaturated soils from CPT using the soil behaviour type index 50 . Giacheti et al 51 . investigated the field measurements of CPT in an unsaturated clayey sand and indicated significant influence of suction variation owing to seasonal changes on the CPT results.…”

Section: Introductionmentioning

confidence: 99%

Interpretation of CPT in unsaturated sands under drained conditions: A numerical study

Keshmiri

Ahmadi

2021

Num Anal Meth Geomechanics

View full text Add to dashboard Cite

A finite difference‐based numerical model simulating the cone penetration process in unsaturated sands is presented. Mohr–Coulomb model (MCM) with simple modifications and Sun model (SM) were implemented to capture the unsaturated sand behaviour. It was shown that the cone tip resistance values resulting from the two models were fairly comparable. Predicted cone tip resistance values in dry, saturated and unsaturated sands using MCM were validated by the results of field and calibration chamber tests. Sensitivity analyses were performed, and the influence of parameters including relative density, mean effective stress and apparent cohesion due to suction on the tip resistance was investigated. Based on a large number of numerical analyses, a simple relationship was suggested to predict the cone tip resistance in dry, saturated and unsaturated sands. The accuracy of the proposed relationship was evaluated by a large database of Cone penetration test (CPT) results performed in various calibration chambers containing different sands. Finally, the applicability of the suggested equation in the estimation of the soil relative density and friction angle from CPT results was shown through useful and practical charts and illustrative examples.

show abstract

“…This type of tropical weather can lead to variations in the in-situ soil suction since it features high annual temperatures with wet summers and dry winters. The seasonal variation's influence on soil suction can lead to significant changes in the in-situ test data, as discussed by Giacheti et al (2019) based on CPT data. Figure 2 shows the soil profile together with dry unit weight (g d ), void ratio (e) and Atterberg limits (w L and w P ) of the studied site up to 12 m depth.…”

Section: Study Sitementioning

confidence: 99%

“…It is important to consider seasonal variability in these soil sites caused by soil suction, which is related to the water content through a soil-water retention curve (SWRC). Therefore, the behavior of unsaturated soils cannot be considered without taking into account soil suction (y) and the site variability (Giacheti et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

Prediction of Load-Settlement Curves by the DMT in an Unsaturated Tropical Soil Site

Silva¹,

Rocha²,

Giacheti³

2019

Self Cite

View full text Add to dashboard Cite

Several methods for prediction of the load-settlement curves of shallow foundations have been proposed based on in-situ testing data. However, the good accuracy of such prediction depends on the definition of appropriate soil stiffness. Seasonal variability and its influence on the soil behavior need to be considered for unsaturated tropical soils. In this context, this study uses a procedure to determine the complete load-settlement curves of shallow foundations by the flat dilatometer test (DMT) in an unsaturated tropical soil site, considering seasonal variability. The DMT and the plate load tests carried out at the experimental research site of the University of São Paulo (São Carlos, Brazil) are presented and discussed. It was found that the DMT is an adequate test for predicting soil stiffness, and the presented procedure allows a good estimate of the complete load-settlement curves. It was also observed that seasonal variability should be considered in the prediction of such curves for the studied site.

show abstract

Seasonal influence on cone penetration test: An unsaturated soil site example

Cited by 25 publications

References 23 publications

Experimental study on the mechanical properties of Guiyang red clay considering the meso micro damage mechanism and stress path

Experimental study on the mechanical properties of Guiyang red clay considering the meso micro damage mechanism and stress path

Interpretation of CPT in unsaturated sands under drained conditions: A numerical study

Prediction of Load-Settlement Curves by the DMT in an Unsaturated Tropical Soil Site

Contact Info

Product

Resources

About