Abstract:The article is a description of the laboratory testing of transient heat flow in small-size samples of concrete and analysis of the impact of spacers made of a polyurethane material to the flow and the temperature distributions in the sample. This problem affects the working of concrete structural members exposed to a wide range of temperatures, and the thermal stresses generated in them, especially when the heat flow is analysed by a combination made of a flexible connection. The results can be used in issues related to the durability of concrete elements and their connections.
Abstract:The numerical simulation of time evolution of thermal and mechanical fields in a selected section of a massive concrete dam was undertaken by means of the Finite Element Method (FEM) using 3D modelling. Low- (i.e. with time period – year) and high frequency (i.e. with time period – day) cycles of environment temperature variation were considered. The results of the computation confirmed the hypothesis of the vulnerability of the structure to thermal influences and explained the mechanism of the structural defects observed.
Abstract:The main aim of this article is to show how different ways of modelling a construction process of soldier pile walls influence the development of the computational lateral earth pressure in this type of structure. Moreover, the paper includes an analysis of soldier pile systems designed in both traditional (Coulomb, Rankine etc.) and numerical approaches. In order to analyse the above problems, several numerical models of soldier pile walls were built and the results obtained were then compared.
Abstract:This case study of the Racibórz reservoir discusses the application of a determination method of characteristic flow values below retention reservoirs. The study describes the selected theoretical foundations, the individual steps of the Monte Carlo (MC) method used to generate hypothetical flood wave hydrographs, and the results of simulations leading to the determination of characteristic flow values below retention reservoirs. The method is based on probability density functions for a multidimensional random variable obtained using copula link functions. The results of the analyses are represented in tables and graphs. The results of the simulation analysis are presented for comparison purposes, assuming a constant and a variable time for the hypothetical base flood elevation.
Abstract:The primary purpose of this article is to present the concept of quasi-spatial monitoring of seepage and erosion processes and phenomena in the area of georisk, using invasive instrumental measurement methods, including, in particular, linear or quasi-linear measurement sensors. Along with the risk of water overflow over the crest of earth damming hydraulic structures, these processes and phenomena pose the main threats for their safety and are the main causes of their repairs. The proposed solutions seem to be valuable ones and have a high application potential. Taking into account the development of measurement methods and the field of the automatic control of the condition of a structure, they will probably be used increasingly frequently in the damming hydro-engineering constructions.
Abstract:This paper presents an analysis of possible uses of contemporary data acquiring methods for elaborating hydrotechnical object numerical models. The subject is considered in two aspects – preparation of a geometrical model based on the results of a geodetic survey of the structure as well as subsoil parameters, and data acquisition for building material characteristics. The results presented for non-invasive measurements of hydrotechnical concrete parameters and geometry of the modelled object are based on the example of Rożnów Dam. The research uses data obtained by terrestrial laser scan and sclerometer tests (taken with a Schmidt hammer).
Abstract:The use of numerical methods for the design and analysis of hydraulic engineering structures requires an accurate determination of the model of subsoil structure. The article presents one of the geophysical methods – electrical resistivity tomography (ERT), which allows for precise, spatially instant recognition of the substrate and the phenomena occurring within it. The methodology, the applied algorithm for numerical calculation, and data processing procedure are discussed. This article also introduces a method of inversion which relies on finding the actual model and presents examples of its application.
Abstract:The paper presents a comparative analysis of the consolidation of soil under a road embankment reinforced with stone columns. The results were obtained from the most common analytical and numerical methods applied in driven column dimensioning. The analytical approach exploits Terzaghi’s one-dimensional theory and Barronʼs three-dimensional theory. The numerical calculations reflected the particular stages of the embankment construction in various two- and three-dimensional systems. The geotechnical parameters that were crucial for the research were determined on the basis of geoengineering documentation, laboratory and field studies. The paper begins with a short introduction presenting the dynamic replacement method.
Abstract:The paper presents barrettes, which are a useful method of designing non-direct foundations of engineering construction. The methodology is based on the distribution of forces acting on a foundation capping slab into each barrette, which depends on its stiffness. To determine the proper stiffness of an individual barrette comprising the foundation system, the transformational function of a pile with large diameter was used. Finally, the stiffness of each barrette as an element of foundation system was corrected in view of the groupʼs impact.
Abstract:This paper discusses the results of numerical simulations of unsteady heat flow in a concrete rod. The temperature distributions obtained are compared with experimental results. The main goal of this paper is to find soil thermal parameters values for concrete which leads to obtaining the best correlation between the measured and calculated temperatures.
