The paper presents an estimation of liquefaction susceptibility of some soils from the coast of the Marmara Sea, which was heavily

striken by the Kocaeli earthquake in 1999. Firstly, the results of field investigations are summarized. Then, the results of laboratory investigations of physical and mechanical properties of the soils collated from the sites investigated are presented. The mechanical properties relate to the compaction/liquefaction model of saturated soils. This model is briefly outlined, then respective experimental procedures dealing with its calibration described, and values of material parameters listed. Liquefaction potential of investigated soils is analysed using standard procedures, based on the grain size distribution curves and SPTs. Finally, the simulation of pore-pressure generation and onset of liquefaction of Turkish soils is carried out, using the compaction/liquefaction model. Discussion of some standard empirical procedures of estimation of liquefaction potential of saturated soils, conducted from the analytical point of view, is also presented.

In the paper the issue connected with water network failure regarding the soil conditions was presented. Water pipes constitute a large part of water company asset. Therefore the analysis concerning the influence of soil conditions into failure occurrence of water pipe is crucial for proper functioning of water supply systems (WSS). In the performed studies the real data from the operation of the exemplary WSS was obtained. The following properties of the ground conditions were taken into consideration among others: the chemical composition and ground phase, based on analysis performed through the following equipment, as the electron microscope with X-ray spectrometer detector and backscattered electrons (BSE) using the powder Debye-Sherrer’s method and X-ray diffractometer. The analysis indicate dependence between soil conditions and corrosivity occurrence, what indicate the importance of performed analysis.