The properties of soils are highly complex, and therefore, the classification system should be based on multiple perspectives of soil properties to ensure effective classification in geotechnical engineering. The current study of research demonstrates a lack of correlation between classification systems based on soil plasticity and those based on in-situ mechanical properties of soils. A CPTu-based plasticity classification system is proposed using the soil behaviour type index (Ic), with its reliability and limitations discussed. The results indicate that (1) Ic has the capacity to predict the stratigraphic distribution from the in-situ mechanical properties of soils. It showed a significant linear correlation with wL, which soil classification zone was similar to that of clay factor (CF); (2) A CPTu-plasticity classification system is proposed to characterize both plasticity and in-situ mechanical properties of soils. This system allows for the initial classification of soils solely based on CPTu data. Furthermore, it has been established that Ic = 2.95 can delineate the boundary between high- and low-compressibility soils. (3) The error is only 25.2% relative to the Moreno-Maroto classification chart, and the system tends to classify soils of intermediate nature as clay or silt. The distance between the data points and both the C-line and the new C-line (Delta Ip, Delta IpIc) showed a significant positive correlation. Only one data point was misclassified, considering human error in measuring Ip. (4) The new classification chart has been found to be more applicable to offshore and marine soils.

The city of A & iuml;n T & eacute;mouchent, located in northwest Algeria at the westernmost part of the Lower Cheliff Basin, has experienced several moderate earthquakes, the most significant of which occurred on 22 December 1999 (Mw 5.7, 25 fatalities, severe damage). In this study, ambient noise measurements from 62 sites were analyzed using the horizontal-to-vertical spectral ratio (HVSR) method to estimate fundamental frequency (f0) and amplitude (A0). The inversion of HVSR curves provided sedimentary layer thickness and shear wave velocity (Vs) estimates. Additionally, four spatial autocorrelation (SPAC) array measurements refined the Rayleigh wave dispersion curves, improving Vs profiles (150-1350 m/s) and sediment thickness estimates (up to 390 m in the industrial zone). Vs30 and vulnerability index maps were developed to classify soil types and assess liquefaction potential within the city.

The generation of negative excess pore water pressure (u2) during cone penetration test (CPT) in a given environment represents a deviation from the actual situation, thereby affecting the accuracy of the parameter inversion. Dissipation tests have been conducted to ascertain the dissipation of the u2 over time, which in turn allows for the parameters to be corrected. However, the tip resistance (qc) and sleeve friction resistance (fs) in dissipation process also vary with time, despite its potential impact on the inversion process. In this paper, the evolution of qc and negative u2 with time is successfully obtained through the utilization of indoor CPTs on silt soils. In conjunction with a viscoelastic model, the existence of stress relaxation of qc is demonstrated and the causes of qc decay are analyzed. The detailed conclusions are as follows: (1) The CPT parameters obtained from the dissipation test can be employed to rectify the discrepancy in negative u2 that arises during soil classification. (2) The qc undergoes a gradual decrease, reaching a final equilibrium state during the dissipation process. The stress-time relationship is consistent with the Three-element viscoelasticity model, which represents a stress relaxation phenomenon. The relaxation process can be divided into three distinct phases: fast relaxation, decelerating relaxation, and residual relaxation. The residual stress is found to be correlated with the depth of the soil layer. (3) During residual phase, the loss rate of qc is observed to decrease in a linear fashion with the rate of u2, prior to which the relationship is exponential. As the penetration rate increases, the rate of u2 also increases.

The earthquake sequence that occurred on February 6, 2023, centered in T & uuml;rkiye caused extensive loss of life and significant damage. In this study, the geotechnical properties of the central districts of Malatya province, one of the provinces affected by these earthquakes, were calculated using data obtained. In the calculations, the correlations suggested by the Turkish Building Earthquake Code (TBEC) and internationally recommended correlations were used. Thus, the difference between the methods proposed by TBEC and internationally recommended correlations was interpreted. Using 1890 drilling data, 1765 seismic data, and 1764 microtremor data, calculations were made to determine bearing capacity values for 3 m x 3 m pad foundation, liquefaction potentials of the soil and soil classifications around this region. The results obtained from the calculations were mapped with geographical information systems-based software. Results of the study revealed that 2.9% of the study area in Battalgazi district and 1.71% for Ye & scedil;ilyurt district had liquefaction potential. Almost 80% of each district was found to have a soil class of ZD (medium dense gravel and sand or clay layers) according to TBEC. The findings of the study were compared with previous studies, satellite images of the study area and post-earthquake observations. In areas where damage caused by the earthquake sequence was observed intensively, bearing capacity values were relatively low. It was concluded that building on poor soil conditions poses a profoundly serious risk in terms of earthquakes and very serious precautions should be taken by gathering several disciplines during the construction of these structures.

This study demonstrates the feasibility of utilizing machine learning (ML) for routine identification of sand particles. Identifying different types of sand is necessary for various geotechnical exploration projects because understanding the specific sand type plays an important role in estimating the physical and mechanical properties of the soil. To accomplish this, dynamic image analysis was employed to generate a substantial volume of sand particle images. Individual size and shape descriptors were automatically extracted from each particle image. The analysis involved use of 40,000 binary particle images representing 20 different sand types, and a corresponding six size and four shape descriptors for each particle (400,000 parameters). Six ML models were trained and tested. The work demonstrates that using size and shape features the models efficiently identified up to 49% of individual sand particles. However, when clusters of particles were considered in conjunction with a voting algorithm, classification accuracy significantly improved to 90%. Among the ML models studied, neural networks performed the best, while decision tree exhibited the lowest accuracy. Finally, the use of size consistently outperformed shape as a classification parameter but combining size and shape parameters yielded superior results across all sands and classifiers. These findings suggest that ML holds much promise for automating sand classification using ordinary images.

This study examines the structural characteristics and post-earthquake damage status of 2790 buildings in Antakya downtown after the Kahramanmara & scedil; earthquakes.The study reveals how structural features, especially building typologies, construction year, number of floors, ground, and load-bearing systems, affect damage status of buildings.Damage levels resulting from the earthquake were documented, and the causes of these damages were identified.Comparisons and analyses clarify the possible vulnerability and risk status of these structures, based on studies conducted before the earthquake.This study emphasizes the importance of post-earthquake structural analyses, damage assessments, and supports future building projects and measures to be taken against earthquake risks.

Diatomaceous soils as a special soil containing diatom frustules are widely distributed in marine deposits. Although their soil properties have been partially tested and reported which exhibit high void ratio and compressibility, a thorough investigation is in lack. Moreover, the interpretation of the cone penetration test (CPTu), a widely-used in-situ test, to the properties of such soil is still unknown, hindering a proper estimation of the diatomaceous soils in engineering geology and geotechnical practice. This study reports the soil properties and mechanical behavior of the undisturbed diatomaceous soil obtained from Walvis Bay in Namibia, which shows that the soils had an extremely high void ratio (similar to 4.39) and low specific gravity (similar to 2.16), and consequently low density and high compressibility. Due to the porous property of diatom frustules, the diatomaceous soils also exhibited a high liquid limit and plastic limit. Although these properties provide an identification to super soft soils, the diatomaceous soils had discrepant mechanical properties, i.e., the values of strength parameters in diatomaceous soils were higher than those in typical soft soils. At the end, by comparing the results of strength parameters obtained from the laboratory tests on undisturbed soil samples and the in-situ CPTu records, this paper proposes the interpretation methods of CPTu results to the strength parameters (effective friction angle and undrained shear strength) in the diatomaceous soils.

The study of deformable soils is one of the key factors in determining the tire, vehicle and/or agricultural tool design parameters. This literature review provides a brief overview of soil classification, soil testing, soil constitutive models, and numerical approaches utilized to model soil-tire/tool interaction. In the past, empirical, semi-empirical, and analytical soil models were used in these studies. However, some limitations occurred in terms of characterization of soil-tire/tool interaction in detail due to a large number of variables such as cohesion, moisture content, etc. In the last few decades, the finite element (FE) method was used with different formulations such as Lagrangian, Eulerian, and Arbitrary Lagrangian Eulerian to simulate the soil-tire/tool interaction. Recently, particle-based methods based on continuum mechanics and discrete mechanics started to be employed and showed good capability in terms of modeling of soil deformation and separation. Overall, this literature review provides simulation researchers insights into soil interaction modeling with tires and agricultural tools.(c) 2023 ISTVS. Published by Elsevier Ltd. All rights reserved.