Papers by Keyword: Foundation

Abstract: The result of the research aims to provide a foundation structure that reduces the amplitude of oscillation of machines and equipment from various technical causes and natural phenomena, preventing resonant phenomena and economical use of foundation material. The proposed foundation, compared to existing foundations, provides a decrease in amplitude and prevents the phenomenon of resonance of vibrations of foundations for machines and equipment creating savings in the use of cement-concrete material. There is considered mathematical, structural, and practical modeling of anti-vibration foundations of mechanical installations in this article. The purpose of the study is to create a foundation design that reduces the amplitude of oscillation of structures from various technical reasons and natural phenomena, prevents resonant phenomena, and economical use of foundation-reinforced concrete material. The research results can be used in the design of foundations of piston machines and equipment used in the oil and gas industry.

Abstract: Systems of floor insulation on the ground, isolation of roads and shallow foundations suggest the use of heat-insulating products resistant to moisture, the minerals contained in it, having low heat conductivity and water absorption and relatively high strength for compressive loads.The aim of the research was to study the possibility of using mineral substances containing crystalline water as a dispersed component. Firstly, such compounds as a reinforcing component increase the strength characteristics of products. Secondly, being flame retardants, they contribute to increasing the fire safety of materials and building systems in which these materials are used. To achieve this goal, two particular tasks were set: determination of the optimal consumption of mineral modifying additives; assessment of exploitative stability of the received products. It was found that the introduction of a mineral modifying additive can significantly increase the compressive strength by 10% deformation of samples from extruded polystyrene foam. The exploitative stability of products with a mineral additive varies slightly and depends on its consumption and uniform distribution in the product matrix. The effect of additive consumption on the change in the thermal conductivity of products has not been established. A nomogram has been built which allows one to evaluate the properties of products and determine the optimal consumption of a modifying additive.Systems of using products from modified extruded polystyrene foam in monolithic foundations with insulation for buildings erected on problem soils are considered.

Abstract: Through the long-term load creep test of CE131 geonet and SD L25 retaining wall foundation, which are widely used in reinforced earth engineering, a large number of experimental data are obtained. On this basis, the least-squares and BP neural network are used to predict its creep variables. The principle of least squares is to find a curve in the curve family to fit the experimental data. From the sum of the squared errors σ = 0. 001 16, the fitting accuracy is higher. The BP neural network has adaptive learning and memory capabilities, especially the three-layer BP neural network model. The maximum error between the predicted value and the actual value is 0.91%, which is a lot better than the error of the least square 3.4%. This method Found a new way for creep prediction.

Abstract: The mature stage of field production is reported to observe a significant decline in oil production rates; watercut either grows slowly or (with the regulation of the production processes) somewhat stabilizes. In some periods, it even somewhat decreases, usually due to the cut-off of the highly watered well stock. During the multi-foundation field production, joint exploitation of the productive foundation is often applied; these foundations are often allocated to different sites. The research objective is to justify the directions for further production of the geological and commercial site, which is at the mature production stage; choose the most technologically "productive" and economically feasible interventions in order to increase oil recovery. Applying the classical methods of geological-field analysis and calculation of displacement characteristics, the main trends in the field production have been revealed; using the data of field and geophysical research, the reasons for obtaining unsatisfactory results in joint foundation operation have been revealed.

Abstract: The paper deals with strengthening structures against punching shear with focus on strengthening of existing concrete foundation slabs. These can be slabs of basements of residential, administrative and other buildings. Also, foundations slabs placed on piles can be considered. This is very specific case of strengthening where only one surface of the structure is accessible. Strengthening is often designed using massive new bearing elements, which are space-demanding. Attention is paid to the development of technology that minimizes the resulting constraints on the surrounding area and is sufficiently effective. Inspiration is strengthening of ceiling flat slabs with additional shear reinforcement. Compared to the ceiling slabs, a larger load must be bear to the foundation structures and therefore the shear reinforcements demand larger dimensions. Mechanical expanded anchors are used for anchoring on the inaccessible side. A significant contribution of mechanical anchoring is demonstrated in the tests results which make possible more efficient design of additional punching reinforcement.

Abstract: Interaction analysis between foundation structure and subsoil and credential assessment of stress in the subsoil and internal forces in foundation structure are discussed in research conferences and scientific journals in the long term. Since 2012 research team at Faculty of civil engineering VSB - TU Ostrava has tested a few slabs with dimensions 2 x 2 m with thickness from 0.12 to 0.2 m. Complex testing comprises measurement of slab deformations, stress in the subsoil and measurement of stress in foundation slab using strain gauges. Slabs were made of plain concrete, reinforced concrete, pre-stressed concrete and fibre concrete. In the paper there are particular test results of stress measured in the foundation structure. Measured values are compared with calculated values. Strain gauge measurement efficiency and optimisation is discussed.

Abstract: Foundation of building on concrete piles is often used when it is necessary to carry the load into larger depth as by common foundation. Bearing capacity of piles or piled raft foundation is wide area to research. This paper deals with experimental load test of concrete pile and with their numerical modelling. Several types of foundation construction were tested and two kinds will be presented and compared in this paper - reinforced concrete foundation slab and raft foundation (made of reinforced concrete foundation slab supported by drilled reinforced concrete pilot). These types of foundation constructions were constructed as models, in a reduced scale, approx. 1:10. The size had to be adjusted due to limited capacity of the testing equipment and financial reasons. Except measuring of the foundation behaviour, there was also carried out measurement of the adjacent terrain.The aim of this paper is to compare the behaviour of rigid slab and the piled raft. The measurement results will be then compared with the results of numerical modelling.

Abstract: Classic connection between prefabricated reinforced concrete columns on a foundation slab using the concrete plinth base can sometimes be very problematic, especially in limited construction conditions and / or foundation on sandy terrain where the groundwater is very close to the ground surface. By applying the screw connection between a prefabricated reinforced concrete column and the foundation structure using anchor bolts and column shoes, the overall height of the foundation is successfully reduced. The established connection between prefabricated reinforced concrete column and the foundation can immediately sustain the design force after assembly and it is considered to be a rigid connection that acts as an equivalent conventional connection with concrete plinth base, without any other additional support and welding. The successful implementation is possible with underground levels of structures where the inverted concrete plinth bases are implemented - the indentation in the foundation slab for the connection of prefabricated columns with base plate is avoided.Application of the screw connection also enables the design of the continuation of the column at higher altitude (column to column) or connection of the upper part the element with the monolithic structure. Screw connection is particularly suitable for use in seismic areas because the performed tests showed very good ductility of the connections under cyclic load.

Abstract: Drying masonry building structures using high-frequency electromagnetic radiation, so-called microwave technology in construction practice is becoming more common. It is an innovative method which can be used to remove excess moisture with significant speed. This article focuses on the description of physical phenomena that occurs during drying and compares the most commonly used processes for drying buildings. This article describes the heating of building materials (basement spaces built from full burnt bricks) using microwave radiation. It assesses the depth of the heating process achieved under different conditions while taking account of various moisture content of irradiated material and varied length of heating.

Abstract: Like the foundation structure, their proper design and good execution plays an important role in the issue of durability of structures, it is also very important to properly design and implement the base layer of foundation structures. Usually, the base layer formed viable subsoil, which are located in the subsoil. Substructure then form the base layer interaction system. The subsoil is not always such a layer that would allow the establishment directly to solid ground. Also, the material (mass concrete, reinforced concrete) foundation structures determines whether it is possible to establish a building directly on the hard soil or underlayer is necessary. Often such a base layer performs building materials arising as waste during mining (eg. coal) or as waste generated in blast furnaces (slag). Often the buildings are well established on the embankments. Individual types of base layers (subsoil) will be evaluated by a team of experts. The team consisted of 43 experts. These experts conducted an evaluation of each type of subsoil individually using the universal matrix of risk analysis - Umra. Umra method is based on the principle of comparative logical and numerical analysis assessing the degree (severity) of a danger to the the project or its component parts. A team of experts assesses the identified part of the problem (the project), which is subject to a certain risk. Number of parts of the problem evaluated by a team of experts is arbitrary, with different (or identical) parts can be handled independently by different expert teams with different number of experts.