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Pressuremeter Test (PMT) and shear wave velocity (Vs) are two important in-situ tests for determining soil deformation characteristics in different strain levels. The PMT is an expensive and time-consuming test that can measure pressuremeter modulus (E PMT) of soil and rock. The Vs is a low-cost test for determining soil deformation through the seismic method. So finding the relationship between PMT and Vs can be useful and cost-saving for cross-checking the parameters obtained by these two methods. In this study, 94 PMT and Vs tests were carried out on silty clay and clay soil from 3 sites in Iran, and the relationship between E PMT and Vs was investigated using regression analysis. Finally, the best statistical model for relationships was proposed according to the highest value of adjusted R2 and Fisher coefficient (F) and a minimum value of significance (Sig.). The results showed that there is a direct relationship between E PMT , Vs, and N 60 with depth then the soils with higher relative density are at the deeper layers. On the other hand, there is a linear significant relationship between E PMT and Vs for each site with R2 > 0.79. When the data for all three sites are considered together, R2 decreased to 0.62 but the overall trend of the data is similar. Due to the similarity of the soil of the three sites in terms of classification, minor differences in plasticity index and water content ranges in the three sites can be a reason to reduce the R2. The comparison between estimated E PMT based on proposed equations in the present study and measured E PMT shows that the normalized consistency ratio is generally close to zero (−0.09 < CR < 0.06) so the equations are valid and reliable. A comparison of the results of the present and a previous study showed that the change rates of E PMT and V S were similar so that the CR values are generally close to zero (−0.09 < CR < 0.09). The minor difference between the E PMT and Vs in each site in the present study and the previous research is due to the soil type and plasticity specifications. • PMT and V S are in-situ tests for determining soil stiffness in different strain levels. • There is a direct relationship between E PMT , Vs, and N 60 with depth. • There is a linear relationship between E PMT and Vs for silty clay soil. • The relationship between E PMT and Vs depends on the plasticity index. [ABSTRACT FROM AUTHOR]

We explore changes in magnetic susceptibility (χ lf), and various forms of Fe and ferrimagnetic minerals after incubation by crude oil in four different textural soils. Four soil classes: clay, sandy, silt loam and sandy loam, were collected in central Iran and incubated with 0, 2.5, 5.0, 7.5 and 10% w /w of crude oil at 80% moisture of field capacity for 1, 3 and 6 months. After each period of incubation, various forms of Fe using extraction techniques, χ lf and total petroleum hydrocarbon (TPH) were measured. In addition selected samples from the four soil types were analyzed by XRD for characterization of ferrimagnetic minerals. The results showed that all forms of iron and magnetic susceptibility increased significantly with increasing concentration of crude oil and incubation time. The highest dithionite extractable iron (Fe d), χ lf , as well as the ratio of Fe d to oxalate extractable iron (Fe o) were obtained for 10% w /w crude oil after 6 months incubation due to formation of ferrimagnetic minerals. The increase in the concertation of ferrimagnetic minerals (magnetite/maghemite) was verified by XRD. Significant positive correlations were obtained among χ lf , Fe d and TPH after 6 months of incubation. The results from this study confirm that magnetic methods can be used as a quick and cost-effective means for evaluation of TPH in polluted soils during the remediation, as compared to the chemical analyses. • χ lf and ferrimagnetic minerals following incubation with crude oil were studied. • Forms of iron showed significant difference among applied treatments. • Magnetic properties of the soil enhanced with increasing crude oil pollution. • Magnetite/maghemite were increased by pollution and incubation time. • Intensity of the peaks with χ lf in four soils showed high positive relationships. [ABSTRACT FROM AUTHOR]