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.

After the demolition of the brutalist Transgas building on Vinohradská street in Prague, whose buildings were situated above the historic Vinohrady tunnels II and III, the Vinohradská Administrative Center and the completion of building no. 345 “Above the Museum” will be built. Both buildings have a foundation joint immediately above the lining of the existing tunnels. The paper describes the main phases of construction, the character and size of the deformation affecting the stone block lining of tunnels.

In simplified engineering calculations, the thermal-technical properties of wood are considered to be constant, but in real conditions they are moisture-dependent. This paper deals with the long-term measurement of absorbency at different initial and boundary conditions for the formulation of the coefficient of liquid water transport in wood for advanced computer modelling. A measurement procedure was designed to eliminate the effect of moisture transport in the measurement of water capillary uptake during partial immersion.

The paper deals with the possibilities for use of glass recyclate from photovoltaic panels for concrete masonry units. It compares partivular recipes and its physical and mechanical properties with the main focus on the compressive strength. It then compares the values of these recipes with the values of commonly used composite materials for masonry units without recyclates.

The present time in the Czech Republic brings a number of diagnostic problems and therefore the diagnostics is currently a widely used field for structural assessment. Otherwise, this is not the case with wooden structures. The paper presents groups of diagnostic methods used for diagnostics of wooden elements built into the structure, which are divided according to invasiveness (non-destructive, semi-destructive and destructive). For each group, the methods that are appropriate to the appropriate group and their brief description are named.

Eurocode 1998-5 for the design of earth retaining structures in seismic conditions describes calculation using the Mononobe-Okabe method. This simplified quasi-static procedure is partly very conservative. The article describes the limits of this method, comparison with other approaches in American NHCRP 661 and Chen and Liu method.

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.

The field of diagnosis of structures has been experiencing a dynamic development in the last decades caused by the development and expansion of new NDT methods and instrumentation. At the same time, it is possible to observe changes in the focus of interest in this field, or more precisely, alternating waves of interest in specific types of diagnosis targeted at special types of structures. These waves of interest are always caused by a certain trend in the development of the society or building industry, and most often, by some major even in the field. In the last few years, particular attention has been paid to prestressed structures, especially to bridges, in connection with the recent accidents of bridges made from prestressed concrete in the Czech Republic and abroad. Considering the relatively large number of these bridges in the Czech Republic built in the second half of the 20^th century, attention is paid to basic changes in the pre-construction condition surveys aimed at determining the condition and the remaining life of these structures. The paper focuses on the analysis of possibilities of assessing the condition of prestressing steel at the level of the present state of diagnosis of structures.

This article deals with the possibility of using masonry aggregate from construction and demolition waste. The article summarizes the properties of concrete with a laboratory-optimized recipe with a full replacement of natural aggregate with recycled masonry aggregate. Testing of concrete samples was carried out according to valid standards. The result is a mixture with optimized properties for the production of construction parts.

Very quick process of digitalization in civil engineering is progressing also in the branch of geotechnical engineering. BIM is a part of this process. Mutual interconnection of the 3D model of ground with the 3D model of the geotechnical structure can help to give more clear view on the interaction of this structure with ground. However, at the same time it makes possible better control for all participants of the construction process, particularly if all conditions of this mutual interaction are fulfilled. Whether the main aim of the construction process – that the care devoted to the individual phases of the structure design and execution correspond to the risk with which this structure and ground are connected. Within this context a closer specification of the Eurocode 7 of the second generation will be specified, as it counts with different models.

Internal erosion is one of the most common causes of failure of hydraulic structures. A special case is a backward erosion piping during which an exceeding of critical hydraulic gradient occurs on the edge of the structure foundation interface. This becomes especially dangerous for the structure when the foundation consists of sand or very sandy soil that is very easy to erode. The sand property of erodibility is not yet fully described. In this paper, an experimental device used for the rate of erosion determination for a picked sand is presented as well as a calculation of the erosion coefficient which is usually used to describe soil erodibility. Furthermore, the paper contains critical hydraulic gradients during which the erosion occurred.

This task deals with the properties and the possibility of recycling of thermal insulation materials such as polystyrene and mineral wool, not only from buildings after demolition but also from discarded materials left over after the construction of new buildings. This newly developed material is being tested as a filler for ultra-lightweight concrete where it fills the cavities of ceramic hollow bricks, as a filler for self-compacting concrete (SCC) and for the production of acoustic facing.

The paper offers an overview of the performed analyses, which evaluated the leakage into underground garages in the densely built-up area of the Prague city centre. Only after a comprehensive reassessment of geological conditions, the project and other available information was it possible to determine the probable causes of leakage into large underground parking spaces.

The aim of the paper is to summarize and evaluate individual diagnostic procedures that diagnose reinforced concrete structures damaged by fire. Based on our experience, we tried to design a methodology for the selection and use of individual diagnostic methods and procedures. Knowledge of the objective state construction after a fire is the basis for determining the procedure of its subsequent remediation.

The subject of the complex repair of the ceiling structure of the water reservoir Pasohlávky was the remediation and static provision of the unsatisfactory reinforced concrete structure. The original condition was inadequate, parts of the concrete structure were dropped due to steel due to steel corrosion and small cover layers of concrete.

The article presents a stability analysis of circular arches under various uniform loadings (vertical to the arch plan, vertical to the arch length or radial to the arch axis). Linear bifurcation analysis resulted into critical loadings used for determination of the arches buckling length factors. With the exception of the radial loading the variable axial arch forces need to be taken into account also for the relative Euler basic strut. The analysis covers various boundary conditions of the arches in supports. The study embodies arches with both closed and open cross sections and proved the significant impact of the cross-sectional shape on out-of-plane buckling values. The article outcomes are tables with correct buckling length factors of arches.

This paper deals with new methodology of design and verification of the limit state of punching of ceiling slabs in the prepared prEN 1992-1-1 [2]. The current methodology does not described with sufficient accurancy and with sufficient reliability the behavieur of the slabs structures in the area of supporting on columns and on ends and corners of walls.

The circular economy in construction is currently absolutely essential in the context of limited primary resources. This applies in particular to the use of inert mineral materials created during the demolition of buildings. It is proven that in the period from 2011 to 2018, the share of recyclates from C&DW in the total production of inert mineral materials more than tripled. One of the barriers to higher production of recycled aggregates is the low level of demolition of buildings, which often makes it impossible to carry out quality recycling.

The paper deals with the new Czech standard ČSN 731004 Geotechnical Design – Foundations, Requirements for calculation methods, published in July 2020. The subject of this standard ase simple calculation methods for the design of foundation structures based mostly on conventional analytical methods validated by long-term use not only in the Czech Republic. The standard applies to flat foundation structures, bored piles and displacement piles, micropiles and jet-grouted columns for axial loading. The standard is primarily intended for structures falling under 2. geotechnical category.

The paper is focused on the current issues of protection and strengthening of wooden structures. The wood used for them is a construction material whose mechanical properties are shaped by the nature and because it is also an organic material, it is subjected to various degradation processes. Types of wood protection includes all measures which would protect wood from influences of fungi, insect, weather (temperature, humidity, wind, fire etc.) and can be divided into chemical protection and radiation protection. Chemical protection can be further divided into protection against weather, biological pests and against fire. In our paper the solution of this weakness by photocatalytic materials (namely TiO₂) is presented. Those materials are efficient UV absorbers and they are able to destroy biological aggressors as well. Nowadays, there is not enough information about the interactions between wooden surface and non-photoactive or photoactive form of TiO₂. TiO₂ exists in many morphological forms. The planar particles were chosen for purpose of the experimental investigation. This material was applied on wooden surface for creating a transparent layer. The results are presented in the first part of the paper. If it is necessary to increase the load-bearing capacity of wooden elements, one of the possibilities is to strengthen them by applying a high-strength layer containing carbon fibers. The second part of the paper is devoted to this procedure with a detailed description of how to implement and design this reinforcement.