This paper attempts to relate the parameters obtained from CPTu static sounding and DPH dynamic test conducted in non-cohesive alluvial deposits of the Vistula River. The investigation was carried out in eight test stations located on the left bank of the Vistula River in Warsaw. The presented theses were based on the results of static CPTU and dynamic DPH tests obtained at 8 test stations. Additionally, in order to associate the obtained sounding results to the lithological type of the tested medium, drillings and grain size analyses were performed. The correlation of the different test methods stems from the need to identify and explain observed discrepancies against the background of different geological conditions, such as moisture content or grain size distribution. The comparative analysis of the parameters obtained from static and dynamic probing, is relevant to the alluvial sediments formed the lower over-flood terrace (called “the Praski terrace”) of Warsaw. Based on the comparison this paper proposes a correlation between the cone penetration resistance the sleeve friction and the number of blows, expressed by the functional relationship. Differences in the matching formulas were shown depending on the saturation of the tested sediments. Correlations were referred to a soil type, which enabled to specify the range of applicability of the proposed relationships. The results of the study were further used to show their diversity using statistical methods. This made it possible to assess the variability of the parameters of the non-cohesive soil, which forms a single lithogenetic unit.

Engineering activity may lead to uncontrolled changes in the geological environment. This paper presents an example of structural changes in fluvial sand of the Praski terrace (in Warsaw) caused by the activity of a temporary concrete batching plant. Our investigations made it possible to identify the material responsible for the structural anomalies observed in the bottom of the trench excavation. The compound responsible for the cementation phenomenon was identified as ettringite – hydrated calcium aluminosulphate: Ca ₆Al ₂[(OH) ₁₂(SO ₄) ₃]·26H ₂O. The source of ettringite were most probably significant volumes of contaminants coming from the temporary concrete batching plant (e.g., from the rinsing of concrete mixers and/or installations for concrete storage and transportation). While penetrating into the ground, ettringite caused extensive cementation of the soil mass, mainly in the saturation zone. As a result, the mineral (chemical) composition of the inter-grain space changed and the structure of the sand was strengthened. The estimated zone of volumetric changes in soil properties was about 6 thousand m ³. However, analysis of the chemical composition of groundwater for its potential sulphate contamination, did not reveal any anomalous concentrations of sulphates.

Petroleum products influence the engineering behaviour of the soil. Neogene clays and glacial tills from Central Poland were tested under laboratory conditions to evaluate the changes of selected physical and mechanical parameters: particle size distribution, particle density, swelling, shear strength and permeability. Four petroleum products were used in the experiments: diesel fuel, kerosene, jet fuel and mineral engine oil. The study revealed that even for the lowest degree of contamination the values of physical and mechanical properties of the soils changed significantly. Greater variation can be expected in soils contaminated with high-viscosity compounds. Also, higher relative changes were found for glacial tills than for Neogene clays. Consolidation tests revealed changes in soil permeability depending on the soil composition and the physical properties of the contaminant – considerable reduction of permeability was observed for glacial tills contaminated with light Jet fuel, while the reduction was lower for Neogene clays. The obtained results indicate the role of mesopores and the dimensionless pore pressure coefficient in changes of soil permeability. The methodological issues regarding testing and analysing the hydrocarbon-contaminated soils were also presented and discussed, which might be useful for researchers studying contaminated soils.