The paper describes how to analytically solve hyperbolic system of partial differential equations describing the boundary effect phenomenon, obtained in the framework of the refined tolerance model of heat conduction in periodic composites [Kula and Wierzbicki 2015]. Basic unknowns of this model are coefficients of Fourier expansion representing the temperature field which represents an alternative exact description of the heat transfer in composite rigid conductors. The aim of this paper is to indicate two sinusoidal-type boundary impulses which cannot be transported independently by the two-phased periodic laminated composite. Investigation of the form of the suppression of thermal boundary fluctuations is important to allow the construction to minimize the destruction of composites caused by the rotations of fluctuation amplitudes which are transported by composite not independently.

The aim of the study is a probabilistic analysis of a steel truss bridge. Structural design parameters were defined as deterministic values and random variables. The latter were not correlated. In the reliability analysis two variants of the description of random variables were considered. In the Variant I the normal distribution was used whereas in the Variant II – different types of probability distribution appropriate for the nature of the variable were proposed. The transformation of normal parameters into the parameters of another distribution was estimated by collocation method at the central point. The criterions of structural failure were expressed by a limit function related to the serviceability limit state and ultimate limit state. The module for symbolic computation using the Finite Element Method was created in the Mathematica software and used to define limit functions for different load schemes. These functions were the starting point for the probabilistic analysis for which the reliability software STAND was used. The Hasofer-Lind reliability index was estimated using the FORM method. In addition, the study presents graphs of sensitivity of the reliability index to the random variables.

The article analyzes the economic efficiency of fixed assets replacement based on the calculation of the net discounted income (NPV). A solution to the problem of choosing the optimal forms and sources of funding has been offered and the simulation modeling algorithm of machinery fleet renewal has been developed. The prospects to use the economic and mathematical modeling of investment support of innovative retooling the machinery fleet in the construction companies of Ukraine has been considered.

Determination of direct slide coefficient and interfacial frictional resistance at the contact between the fill material and geosynthetic was the purpose of the paper. The fill material was an ash-slag mixture from Skawina Power Plant and from the settler of ArcelorMittal Poland Steel Plant in Kraków Płaszów. The shear strength and interfacial frictional resistance tests were carried out in the direct shear box apparatus at the moisture content close to optimal at the compaction indexes 0.90, 0.95 and 1.00. Test results revealed that the shear strength parameters of the analyzed ash-slag were high. The parameters describing the frictional resistance at the contact: ash-slag – geosynthetics were also high, which allowed obtaining high values of the direct slide coefficient as well as the coefficient of interfacial friction.

The development of road investments during past years results in an increasing demand for natural aggregates (NA) which x become a part of the road construction subbase in the form of an unbound mix. In order to decrease investment costs, the Construction and Demolition (C&D) materials, such as fly ash, steel slag or recycled concrete aggregates (RCA), were applied as a subbase fill. The advantage in using these materials, besides the reduction of costs, is a possibility of C&D material recycling and sustainable development, due to replacing the NA, which is a non-renewable source. Among many properties influencing the quality of road material, the California Bearing Ratio (CBR) is the one representing the mechanical properties of unbound mix. This article presents the results of CBR tests on RCA with various moisture and compaction properties, in order to characterise the CBR bearing capacity. The results were then used to form conclusions about CBR tests on RCA. The conclusion can be drown that the C&D materials can be successfully applied in road engineering when more strict regulation will be applied.

The article presents the test results and the analysis of selected properties of bentonites used as isolation barriers of engineering structures, especially landfills. Three types of bentonites were used as a research material and for each of them the dispersivity and swelling ability were assessed. The dispersivity was determined by using the crumb test and the double hydrometer test. Swelling index was determined in the Holtz and Gibbs method and in the method presented in ASTM D 5890-95. The investigations of the influence of liquid pollution with various chlorides concentrations (1000, 2500, 5000 and 10,000 mg·dm^–3) on swelling ability of bentonite were included. The results obtained were compared with values required for typical bentonite materials used as isolation barriers of engineering structures.

The main goal of this paper is to verify the design foundation of the underground SGGW parking. The design foundation assumption was to found all foundations at level of 21.90 over “0” Vistula. Considering the heterogeneous subsoil on foundation zones the verification was undertaken. It was concluded that each foundation should be designed individually. The assessment of design foundation conditions included calculations of ultimate limit state and serviceability limit state was performed. As the calculation results the value of settlement, in accordance with Polish standards PN-81/B-03020 and Eurocode 7 were determined. Calculation results indicated that the foundation at level of 21.90 m above “0” Vistula in IIb geotechnical layer is impossible due to the fail of foundation obtained from both standards applied.

Profesor Czesław Woźniak