The design work on the objects of large area need to know not only surface of object in horizontal projection but also spatial (real) dimensions of the surface. The rapid development of digital terrain models can improve the site of such works. It was developed a number of computer programs to calculate the real (spatial) surface area based on set of DTM held. The possibility of using by the users (designers) the existing and newly created DTM obtained by different methods, will depend primarily on the accuracy of these models. The study subjects were taken effect accuracy of the DTM on the accuracy of calculating the surface area approximated. The conducted analysis can be helpful to users in selecting the optimum data of DTM for the specific purposes, from set of data collected in the state geodetic resources.

The paper presents research sites and results of analysis of behaviour of the ground and structures located within close neighbourhood of several investment units, characterised by diversified impacts, including: deep excavations, mining the underground railway tunnels using tunnel boring machines and construction of buildings. Monitored site is located within inner centre of Warsaw. Performed analysis covers geodetic surveys of displacements and deformations of particular objects, using such techniques, as: precise levelling, precise angular and linear surveys and terrestrial laser scanning. Data obtained by these methods are basis for calibration of numerical models, and vice versa – the results of numerical calculations are basis to determine a method of monitoring the object and determine the expected values of displacements in the different phases of realization of the investment and determine permissible deviations, which are considered as the alarm values.

Considerable differences between predicted and actual – measured in the field – deformation of subsoil create premises for hypothesis that compressibility characteristics of overconsolidated cohesive soils obtained from oedometer tests are incapable to reflect accurately soil behaviour under loading in the field. It results from the fact, that oedometer incremental loading test procedure is simplified to such extent that it does not account for many factors contributing to actual compressibility characteristics. The paper describes an approach to quantification of degree of saturation influence on compressibility characteristics. Test results of overconsolidated medium plasticity clays sampled from route of Mińsk Mazowiecki ring road. It was shown that standard procedure for determination of compressibility parameters does not account for change in degree of saturation during loading, what results in errors in prediction of soil structure interaction. Some recommendation concerning how to account for change in degree of saturation during oedometer test were given.

The paper presents the importance of particles shape of fine-grained non-cohesive soils in water permeability process and its role according to the Eurocode 7. Methods of determining the permeability coefficient based on empirical formulas recommended by the above norm as reliable tools were particularly analysed. In order to the methods evaluation, laboratory test of two fine-grained non-cohesive soil materials were conducted. Tested grounds were characterised by the same grain size distribution and extremely diverse particle shape characteristic. Permeability coefficient calculations verifying this approach based on the formulas most often used in practice were performed. The obtained results were compared with laboratory tests conducted on soil samples which had the same value of void ratio, as used in calculations. The results have shown that using empirical formulas as the methods of permeability coefficient calculation of non-cohesive soil, which is recommended by Eurocode 7, is not a reliable way to determine this parameter, due to insufficient approach or ignoring the soil microstructure factor.

At present cone penetration test is considered to be a well-established method in geotechnical analyses to the point when it is frequently seen as a leading method. Sometimes its results are overestimated due to the status of this method, particularly when soil strength is evaluated solely on the basis of CPT results. At full drainage and a load-bearing subsoil this problem is not significant, but it gains in importance when recorded excess pore water pressure is not included in the evaluation of soil strength under partial drainage or no drainage. The matter of selecting a reliable interpretation procedure constitutes a key element in the proper analysis of cone penetration test results. The paper presents limitations and criteria differentiating the selection of an interpretation procedure for the evaluation of shear strength parameters and a comparison of strength analyses results of soils depending on the type of applied CPT and CPTU.

In the second quarter of 2010, after catastrophic precipitation throughout the country (mainly in the south part), a large number of landslides were activated, what caused damages to infrastructure and buildings. This entailed the need of documenting the geotechnical conditions of landslide areas for the purposes of protection designs of the areas endangered or destroyed by landslides. Geotechnical designing process requires determination of the real values of the strength parameters of soils occurring within the main slope and colluvium of landslide. This paper describes how to determine the strength parameters based on direct testing (triaxial apparatus) verified by back analysis with using numerical stability calculation methods. The geodesic measurements (slope geometry before and during the development of the landslide) and geotechnical tests carried out within the framework of the geological-engineering documentation of the landslide within the Flysch Carpathian Mountains were the base for conducting the back analysis.

The triaxial tests results, performed with use of undisturbed cohesive soils samples, were described in this paper. Shear strength parameters – internal friction angle (ϕ’), cohesion (c') and undrained shear strength were evaluated for soils of various values of plasticity index. Based on tests results analysis the relationship between internal friction angle and plasticity index was presented in respect to used standards and literature. The attention was drawn to the reasons of cohesion overestimating. The recommendations of Eurocode 7 for interpretation of strength tests were evoked too.

The present paper addresses the issues of excavation bottom stability as ultimate limit state HYD of the Eurocode 7. It has been shown that with excavations surrounded by sheet pile walls, the two conditions for ultimate limit state HYD as provided in EC7 procedure different values of the global safety factor. For the stability condition expressed in forces and weights affecting the column of soil at a sheet pile wall, the global safety factor is F = 1.5, while for the condition expressed terms of effective stresses this factor is F = 3. The methodology of calculating the excavation bottom stability according to EC7 was exemplified by a linear excavation.

In the paper the discussion of problems and doubts when analyzing deep foundations, mainly whilst determining soil parameters. Problems and doubts regarding geotechnical calculations, their source as well as methods and solutions to improve compatibility of calculated and measured displacements of buildings are also described. In this part the author examines the possibilities of implementation and the accuracy of the principles of geotechnical parameters modification for soil layers deposited at depths. This has been done on the basis of local relationships taking into account changes in soil stiffness for very small strains. The author discusses cases of such benchmarks utilization and their application benefits as well as presents modifications to parameters defined based on Polish standard PN-81/B-03020 in numerical simulations of deep foundations.

This study is an example of the reconstruction hall depot (WGW), which is located in Leszno. Works include, among other things, the execution and design of the supporting structure for technological equipment in the form of a reinforced concrete chamber. Concerned depot modernization of design and material solutions. The study also illustrates the strengthening of steel structure and describes the numerical model adopted for dimensioning the supporting structure – reinforced concrete chamber – with elements of the coating.

Fiftieth career Professor Wojciech Żółtowski