The problem of designing deep foundations is related to many civil engineering structures as it is becoming more common and frequent to construct buildings on soft soils. Pile foundation is a popular deep foundation type used to transfer superstructure load into subsoil and bearing layers. However, accurate prediction of piles’ settlement is particularly difficult concerning complicated consolidation process and pile-soil interaction. The objective of this paper is to model a soil-pile system using FEM implemented in Abaqus software. The numerical results of pile bearing capacity and pile settlement were compared with static load test results of CFA piles carried out during construction of Łazienkowska tract flyovers in Warsaw and with engineering analytical calculations according to Eurocode 7 and Polish Standard Code

The aim of this work was to study the influence of the type of activator on the formulation of modified fly ash based geopolymer mortars. Geopolymer and alkali-activated materials (AAM) were made from fly ashes derived from coal and biomass combustion in thermal power plants. Basic activators (NaOH, CaO, and Na₂SiO₃) were mixed with fly ashes in order to develop binding properties other than those resulting from the use of Portland cement. The results showed that the mortars with 5 mol/dm³ of NaOH and 100 g of Na₂SiO₃ (N5-S22) gave a greater compressive strength than other mixes. The compressive strengths of analyzed fly ash mortars with activators N5-S22 and N5-C10 (5 mol/dm³ NaOH and 10% CaO) varied from 14.3 MPa to 5.9 MPa. The better properties of alkali-activated mortars with regular fly ash were influenced by a larger amount of amorphous silica and alumina phases. Scanning electron microscopy and calorimetry analysis provided a better understanding of the observed mechanisms.