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Hotel Evropa v Praze
14.6.2021
doc. Ing. Jan Masopust, CSc., ČVUT Praha, Fakulta stavební, katedra geotechniky

The paper deals with the monitoring of deformations during the completion and reconstruction of the Hotel Evropa in Prague. Part of the implementation design documentation was the detailed design of geotechnical monitoring of deformations of the foundation pit. This article presents the main features of the measurement outputs in the form of the vertical and horizontal deformations. Monitoring is one of the most extensive and detailed of all that has ever been implemented in our republic, both in terms of its scope and its duration.

10.5.2021
doc. Ing. Karel Vojtasík, CSc., VŠB TU Ostrava, FAST, katedra Geotechniky a podzemního stavitelství

The determination of the bearing capacity of the micropile from the tensile bearing capacity is based on a comparison of the results of compressive and tensile loading tests of micropiles, which were performed on an external test load frame. The micropiles were first tested with compressive forces and later after about one year the same micropiles were tested with tensile forces. Four grouted micropiles with a length of 3 m, which were installed in loess clays, were tested. The result of the tests are graphs of the dependence of the settlement and extraction of the micropile on the applied forces. These graphs are compared and it is looked for a dependency that would make possible an estimation of the bearing capacity of a micropile in compression from the tensile test.

22.2.2021
Ing. Aleš Jakubík, Ing. Radek Hermann

Example of rehabilitation of sewerage facilities, shafts and chambers in an environment of the historic city center with increased loads of chemical-biogenic corrosion. Possible causes and consequences for both, original and newly constructed, building structures. Modification of the proposed solution, including the design of an appropriate construction structure and installation technology solution.

28.12.2020
prof. Ing. Pavel Kuklík, CSc., ČVUT v Praze, Fakulta stavební, katedra mechaniky

This contribution deals with damage to buildings and building materials due to bad manage of rainwater regime. Effects are divided according to location of damage. First, the damage of roofs and roof trusses is presented, which are followed by examples of damage to the enclosure walls. The most attention, including numerical 3D modeling, is devoted to damage to foundation structures and foundations.

21.12.2020
prof. Ing. Jiří Witzany, DrSc., Ing. Radek Zigler, Ph.D., doc. Ing. Klára Kroftová, Ph.D.

Many historic buildings are located in areas where there is a specific type of earthquake activity, the so-called earthquake swarms, during which a series of thousands of weaker tremors take place for several days or months. Sometimes these shocks are strong enough to be felt by people, and in some cases they can even cause material damage to buildings. Knowledge of the response, especially of vaulted structures of historic buildings to dynamic loads, is the basis of remediation interventions on monumental buildings exposed to these effects. Due to the increasing intensity of wheel and rail traffic, there is also an increase in the effects of the so-called technical seismicity on structures located near roads and tracks. The proposed system of additional stiffening of barrel, cross or of spherical vaults by means of prestressed flexurally rigid segmental ribs contributes to the increase of their resistance to the natural and anthropogenic dynamic effects.

© Sailorr - Fotolia.com
16.12.2020
prof. Ing. Jiří Witzany, DrSc., Ing. Radek Zigler, Ph.D., Ing. Jan Kubát, Ph.D., doc. Ing. Tomáš Čejka, Ph.D., Ing. Jiří Karas, CSc., doc. Ing. Klára Kroftová, Ph.D.

Within the research project NAKI DG16P02M055, an extensive experimental and theoretical research of the influence of grouting on the physical and mechanical properties of brick and stone masonry is carried out. The focus of the research is to verify, in particular, the strengthening effect of selected grouting mixtures based on hydraulic lime (nano-lime), resins and silicates. The influence of grouting on the change of porosity, pore distribution, absorptivity and strengthening effect of grouting of historical brick, marl, sandstone, trachyte, limestone and mixed masonry with lime binder using various types of grouting mixtures in comparison with ungrouted masonry is evaluated. Particular attention is paid to the masonry damaged by cracks and cavities.

21.9.2020
Ing. Ivan Hollý, PhD., Ing. Iyad Abrahoim, PhD.

The present experience has shown, that the most serious effect of the accidental load on prefabricated panel buildings in our conditions is a gas explosion. In addition to the explosion of gas, the effect of elevated temperature during a fire is also significant. During a fire, the mechanical properties of building materials may change. These may not return to their original value at the end of the temperature load. The article describes the design of repair of the load-bearing members the panel building after fire on the 11th floor of the panel system type T-06.

24.8.2020
doc. Ing. Eva Burgetová, CSc., Ing. Denisa Boháčová

The aim of the study was to determine the functional reliability of the historic wall of the Hvězda summer house and to assess its applicability. The article presents the possibilities of freestanding wall renovation design using optimal technologies, analysis of solution proposals and evaluation of risk factors. The actual design of the renovation was preceded by a detailed structural survey. At the end of the article, the course of implementation work is described, including the selected material solution of restoration. The Klokner Institute of the Czech Technical University participated in the material analyses and the renewal proposal was consulted with the National Heritage Institute.

22.7.2020
Ing. arch. Štěpán Mančík, Ph.D., ČVUT Praha, pracoviště UCEEB, Ing. Antonín Lupíšek, Ph.D., ČVUT v Praze, pracoviště UCEEB

The main aim of the project TiCo is to facilitate advantages of prefabrication in building residential houses by connecting two major systems with their strong points – reinforced concrete skeleton for load bearing structure and wooden panel system for facades and partition walls.

1.6.2020
Ing. arch. Jiří Kugl, ČVUT Praha, Fakulta stavební

This paper will focus on the question of how we can work with brownfields and it will deal with tools that enable the revitalization and rehabilitation projects in the area. Tools can be divided, for example in terms of spatial planning and urban design, from an environmental perspective, from the perspective of cultural heritage protection and from the perspective of investment opportunities. The result is that the issue of brownfields is handled by numerous institutions and instruments. The aim of this paper is to identify, classify and analyze these instruments. Paper will study instruments from other countries with long-term experience with this issue (eg. France, Great Britain, USA, Germany, Denmark) and analyse the feasibility of their implementation in the Czech Republic and their contribution. Because this theme is a very complex one, this paper is mainly focused on urban planning tools, economic tools (incentive and penalty) and building tools (designed to uphold the intentions of the municipality or the state by building mainly transport and technical infrastructure).

17.4.2020
Ing. Patrik Šťastný, Katedra technológie stavieb, Stavebná fakulta, Slovenská technická univerzita v Bratislave

The elementary aim of the described research is to prove the necessity of creating an additional impermeable layer acting as moisture insulation of historical structures by means of undercutting technology. From a technological point of view and also based on known research, it is obvious that this technology is one of the most effective remediation methods. Unfortunately, the use of this technology is from the point of view of Regional Monuments Authorities, which, due to adherence to the uncompromising Venetian Charter, is considerably limited, because, despite considerable efficiency, this technology disrupts the integrity of historical vertical structures. The methodology of research into undercutting technology consists in verifying and demonstrating the effectiveness of this technology in various historical buildings and recording individual moisture values in situ before and after the implementation of the technology. The results measured in this way should objectively prove the necessity of using the technology of undercutting masonry as a remediation method of wet historical structures, provided that this does not compromise the statics of the object and this intervention is necessary.

13.4.2020
Ing. Ivan Hollý, PhD., Ing. Iyad , Abrahoim. PhD.

The mass construction of apartment buildings using the technology of large-format prefabricated prefabricated elements in the former Czechoslovakia took about 40 years. The lifetime of these buildings is approaching their planned value. A common problem of prefabricated buildings is the creation of new openings in load-bearing structures without prior expert appreciation. The important details of the joints of the support elements have changed not only between the individual assemblies, but also during the development of the particular assembly. The article describes some problems of load-bearing structures of prefabricated buildings, which designers have to consider in their assessment.

6.4.2020
Ing. Ivan Hollý, PhD., Ing. Iyad , Abrahoim. PhD.

The construction of precast hous consists of prefabricated concrete walls and floor slabs. These elements through joints form rigid spatial (so-called box) load-bearing system. The prefbricated elements of this system were designed for certain layout and static possibilities of the panel system. All additional interventions in the load-bearing structure must be thoroughly investigated. If necessary, it is also necessary to propose a suitable way of strengthening the weakened parts of the load-bearing system.

Pražská Invalidovna, ilustrační obrázek © yakub88 - Fotolia.com
24.2.2020
prof. Ing. Milan Holický, Ph.D., DrSc., ČVUT Praha, Kloknerův ústav

The article presents the basic criteria in the evaluation of structures of historical buildings. The whole procedure is described in detail in EN 13822, Annex I. The intention is also to provide additional guidance on the application of this International Standard for the construction of cultural heritage buildings. The instructions given here are to be followed in conjunction with all other clauses of the internationally applicable standard EN 13822 and other regulations.

© Alterfalter - Fotolia.com
13.1.2020
doc. Ing. Vladimír Tichomirov, CSc., LL.M., Ing. Marek Kervitcer

In this paper, the authors consider the aspects of routine procedure compared to the expert approach in solving construction defects and failures. For better orientation in the issue the basic terminology of defects and failures sphere is given. Also, the authors describe in details the course of both solutions, contemplate their specific aspects and point out their consequences. An essential part of the article is presentation of the potential benefits of the expert approach, the advantages of the expert approach are emphasized in the conclusion.

6.1.2020
Ing. Dagmar Michoinová, Ph.D., Národní památkový ústav ČR, Technologická laboratoř,

The paper discusses the importance of water absorption of traditional building materials and the ability of traditional non-insulated buildings to withstand rising damp. It also draws attention to some of the risks involved in reducing the water absorption of building materials designed for remediation of moisture and salts problems of traditional buildings.

30.12.2019
doc. Ing. Petr Cikrle, Ph.D., Ing. Sabina Hüblová, Ing. Zuzana Oščatková, Mgr. Veronika Singrová

This article describes how to monitor panel house faults. Object movements are measured by a Hollan deformeter (used to measure changes in crack widths and joints) and by floor leveling.

11.11.2019
prof. Ing. Martin Jiránek, CSc., ČVUT v Praze, Fakulta stavební

The article describes all significant changes in the field of designing and implementing radon protective and remedial measures introduced by the revised version of ČSN 73 0601, which came into force on 1.10.2019. A new way of selecting measures according to the building type and new concept of designing according to the design values of input parameters are introduced. A new methodology for designing radon-proof insulations is described in detail. According to this methodology, only insulation with a radon resistance greater than the prescribed minimum radon resistance can be used for building protection.


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