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Risk-based seismic design of reinforced concrete frame buildings using simplified nonlinear models
Get PDFMost current standards that are concerned with the seismic design of buildings do not provide sufficiently clear information about safety against collapse. For this reason a new procedure for the risk-based seismic design of buildings is proposed, which is iterative and based on the use of nonlinear methods of analysis. The proposed design procedure starts by the selection of an initial structure, which is gradually adjusted by means of iterations until the estimated seismic risk is lower than the target risk. Since the number of such iterations may become excessive, simple guidelines have been developed for the structural adjustment of reinforced concrete frame buildings, which can be used to improve the building's strength and deformation capacity by appropriately adjusting the structural elements selected on the basis of the results of pushover analysis from the current iteration. The concept of differentiation in the reliability of design is also implemented, so that less demanding analytical methods are used in the initial iterations, whereas more demanding, and usually more accurate methods are used to verify the design results obtained by using simplified methods. Part of the research was aimed at the improvement of the accuracy of seismic risk estimation, which is an important component of the proposed design procedure. New equations for seismic risk assessment, which take into account the physically defined limits of ground-motion intensity, have been derived. It was found that sometimes, if the lower and upper limits of the ground-motion intensity are insufficiently taken into account, overestimated values of the seismic risk may be obtained. The suitability of the proposed design procedure, which takes into account the newly developed equations for seismic risk assessment, was demonstrated on two examples of reinforced concrete frame buildings, one having 8 storeys and the other 15 storeys. The target risk was achieved after only four and three iterations, respectively, even though their corresponding initial structures had been only roughly defined. Taking into account the upper bound of the seismic intensity can result in a reduction in the estimated probability of collapse, which can in turn have a significant effect on the final design of the structure
Interdisciplinary Definition of a Sustainable Approach to the Environmental Protection - the Case of Castle Heritage
Get PDFTopic of dissertation is integrated preservation of architectural heritage on the case of castles in Slovenia. The aim of dissertation is to contribute to heritage preservation in a way that allows its integration into development\ud
of space and of local environment. Based on research work, presented in dissertation, we therefore developed\ud
multi-criteria methodology for monuments properties assessment. Methodology, as proposed by thesis, embraces\ud
properties of monuments, which can be explored by different disciplines, yet at the same time defines heritage\ud
“potential” for its future use, especially in relation to the planning of its management and function, which would\ud
ensure efficient link of monument with local development. At the same, methodology can be used for science\ud
based renovation and maintenance interventions planning, as the number of castles, in urgent need of such\ud
interventions, exceeds resources available. Methodology is designed to suggest allocation of resources for\ud
interventions to those monuments first, whose assigned priority is the highest according to the state strategy and\ud
respective criteria and objectives of the call. The need for such research has been strong, while at the same time\ud
results of this research come before the state strategy (even though it is prescribed by the law), which would stop\ud
monuments deterioration and introduce clear criteria of state subsidies. In defining criteria of the methodology\ud
we proceeded therefore from the art historical, historical, civil engineering, environmental, administrativeeconomic\ud
and sociological aspects of monument conservation. Methodological approach is interdisciplinary\ud
research, covering methods of art history (style analysis, values assessment and comparative analysis of art\ud
monuments etc.), historiography (critical analysis of primary and secondary sources), sociology (interview\ud
method, analysis, synthesis, method of participant observation), civil engineering (multi criteria decision making\ud
methods, AHP – Analytic Hierarchy Process method, visual inspection of the building state of conservation,\ud
assessment of risks) and partly of the economy and environmental protection field (multi criteria decision\ud
making methods). Castles in Slovenia, declared as monuments of national importance, are the case study for\ud
verification and validation of the methodology, whilst methodology offers also important platform for the\ud
treatment of monuments of local importance, however this approach has not been introduced systematically and\ud
requires further consideration. Research work, presented in dissertation, confirmed the hypothesis that\ud
professionally and science-based multi-criteria decision-making methodology can be important support in\ud
monuments analysis and their integrated preservation. Test methodology has been verified through interviews\ud
with experts from different disciplines and has served for the preparation of methodology proposal, which gives\ud
possibility for integrated interdisciplinary monuments assessment, as well as for definition of methodology for\ud
financing renovation of deteriorated objects and for financing maintenance of those objects, which are in\ud
function and are in satisfactory state of conservation. As crucial it has been pointed out that the state needs a\ud
comprehensive and long-term approach to define function of castles, while at the same time it should not to\ud
expect that the majority of objects will sustain themselves
The analysis of real property registration procedures within the land administration system in Slovenia
Get PDFMaster's thesis presents the results of an analysis of land administration in Slovenia. The data part of\ud
the system of land administration in Slovenia represents three basic land records: land cadastre,\ud
building cadastre and land registry. In the first part of the thesis we examined the legislative\ud
framework where we presented some legal changes, studied processes in the system of land\ud
administration that are necessary for real estate registration, we reviewed the content of public real\ud
estate registration and described the procedures how to access data in public records. The practical part\ud
of the thesis contains analysis of the data from the public registry.For the case study we selected real\ud
estate from chosen company and we formed list of real estate. This list we filled with data from public\ud
registry. We examined the regulation for each type of the real estate. Our analysis was done for plots,\ud
building and part of the building. In thesis we tried to assess how data from the public registry is\ud
consistent with each other
Influence of the connections on the seismic response of precast reinforced concrete structures
Get PDFThe dissertation describes the results of an extensive experimental and analytical investigation into the\ud
effect of connections on the seismic response of precast concrete buildings, which was performed within\ud
the framework of the two European projects: SAFECAST and SAFECLADDING. The investigation was\ud
concerned with two important groups of connections, i.e. those between columns and beams, and those\ud
between the cladding panels and the main structure. Cyclic tests were first performed on specimens from\ud
both groups of connections, after which the failure mechanisms, based on the obtained experimental\ud
results, and making use of detailed 3D numerical analyses, were explained. A number of robust engineering\ud
models were developed, which take into account some of the key characteristics of the cyclic\ud
response of connections of the investigated types. In the case of dowel connections, the effect, on the\ud
load-carrying capacity of the connection, of stirrups, as well as of the large relative rotations between\ud
columns and beams, was investigated. This represents one of the main contributions of the dissertation.\ud
In order to evaluate the effect of connections on the seismic response of whole buildings, an extensive\ud
parametric study was then performed, which examined the fragility and seismic risk of typical singlestorey\ud
and three-storey precast buildings located in Ljubljana. It was found that if the load-carrying\ud
capacity of the dowel connections was inaccurately assessed, then the safety of such structures could be\ud
seriously affected, since the ability of connections of this type to dissipate seismic energy by means of\ud
plastic deformation is relatively low. In the case of the connections between the cladding panels and the\ud
main structure, it was shown that the probability of failure was, in the case when vertical panels are used,\ud
relatively high (between 2.0 and 30% over a period of 50 years), whereas in the case of horizontal panels\ud
it was significantly less (between 1.0 and 5.5%, or between 0.1 and 1.3%, depending on the type of\ud
connections used). Based on the new findings, guidelines were prepared for the design of beam-column\ud
dowel connections, and connections between cladding panels and the main structure. Dowel connections\ud
have to be designed according to the capacity design method, for which their load-carrying capacity\ud
needs to be accurately estimated. In this part of the dissertation some expressions for the calculation of\ud
this capacity are proposed. Methods which can be used to verify the adequacy of connections between\ud
facade panels and the main structure are also given. If the performance of such verification methods is\ud
infeasible, then second-line back-up devices, i.e. restrainers, need to be installed. The design, testing,\ud
and evaluation of the necessary load-carrying capacity of such systems are presented in the final chapter
Energy certificate For single Family houses From three diferent time periodes
Get PDFThe thesis describes and analyses the three typical single family houses, which were built in\ud
1967, 1999 and 2015. A calculated energy performance certificate was done for all three\ud
houses. Measures were also proposed for the older two houses to increase energy\ud
efficiency. It describes issues focusing on legislation governing the areas related to energy\ud
issues and energy certificates with an emphasis on Slovenia and partly on the European\ud
Union. The computer programs TEDI and TOST were used to develop the Thesis. TEDI\ud
allows us to calculate the heat transfer coefficient of construction and TOST is used to\ud
calculate energy balance in accordance to Pravilnik o učinkoviti rabi energije v stavbah\ud
taking into account SIST EN ISO 13790 and TSG-1-004-2010. The main purpose of this\ud
study was to calculate the energy efficiency of buildings and to compare the obtained results.\ud
Analyses showed that the new house (2015) is very energy effecient in comparison with\ud
older houses. It spends forty times less heating energy per square meter of usable area as\ud
the oldest house (1967), and ten times less than the house built in 1999. It turns out that\ud
alredy minimal thermal insulation greatly reduces heat demand of the house, and that we\ud
have witnessed significat progress in use of insulation materials in last fifteen years
The analysis of traffic safety in the area around Trebnje
Get PDFMy thesis focuses on safety on roads R1 215, section 1490, R2 448, section 0220, and R3 651, section 1198. Car accidents and the suitability of geometrical elements on these roads have been looked into and studied. Besides field measurements I made use of the digital orthophotograph. Using the traffic counter that includes speeds I carried out the analysis of the speed and volume of vehicular traffic on sections where speed limits are often exceeded. \ud
I put forward ideas and suggestions to improve road safety on those sections where most offences have been committed. In my thesis I used the following software programs:\ud
AutoCAD, Access, Excel and ViaGraph
Pedestrian crossing safety - evaluation methodology
Get PDFPedestrian crossings are an important part of road transportation systems. They should provide a safe environment for crossing streets. Many crossings are poorly equiped or placed at risky locations with an exessive vehicular traffic volume and high speed limits. To recognize dangerous pedestrian crossing locations and improve their safety, first the criteria for evaluating adequacy of pedestrian crossing should be defined. The thesis proposes methodology for traffic-safety evaluation of pedestrian crossings. It explains factors, which affect crosswalk safety, such as: stopping sight distance, vehicular speeds, pavement surface skid resistance, lightning and appropriate traffic calming treatments. It also describes the method for determining pedestrian delay and crosswalk level of service, which can be included in the analysis of crossing location. Pedestrian crossing safety evaluation methodology is based on EuroTest safety assessments. These have been implemented in Slovenia on AMZS (National Automobile Federation of Slovenia) initiative in the past few years. The traffic safety factors were divided into four groups: crossing system, daylight visibility, nighttime visibility and accessibility. Each group was rated from inadequately to excellent by grades from 1 to 5, whereby the final safety performance is expressed as the average grade of all groups. Using this methodology, pedestrian crossings in the\ud
municipality of Kočevje have been tested. Results are presented in the last part of the thesis
Določanje kazalnikov nizkih pretokov – prikaz na primeru vodomerne postaje Kokra I na reki Kokri
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Buckling of longitudinal reinforcement in RC columns subjected to seismic load
Get PDFExperimental research, as well as analysis of buildings and bridges damaged in earthquakes shows that in reinforced concrete columns longitudinal reinforcement often buckles under seismic loads. The onset of phenomena, the numerical modelling and effect of phenomena on the ductility of reinforced concrete columns are the focus of this thesis. We have summarized a portion of the current research efforts in the field. Then we have described numerical models for nonlinear analysis of reinforced concrete columns and material models which are used to describe buckling of longitudinal reinforcement.\ud
From a wider database of experimental data we have selected a group of specimens that shows signs of buckling. Experimentally observed ultimate displacements of selected specimens were determined from hysteretic responses that were included in the database. We have conducted nonlinear\ud
analysis to predict ultimate displacements of specimens, with or without buckling. Calculated ultimate displacements were compared with experimentally observed. For one specimen we have calculated hysteretic response using different finite elements available in OpenSees.\ud
We have gathered that the buckling of longitudinal reinforcement has little influence on columns that have unsupported length to bar diameter ratio smaller than 6 and have adequate diameter of transverse reinforcement. Although existing numerical models can describe lower resistance of the reinforcing bar in compression, they still have problems predicting displacements of the whole column. For better modelling of reinforced concrete columns models that take into account the interaction between confined concrete core and longitudinal reinforcement should be developed
Glass as a construction material
Get PDFThe goal of this thesis is to analyse tehnical characteristics and usability of glass, used in construction not just as main element of glazing, but also as construction material, which has ability to carry the loads. I will represent recent procedures of planing with carry – load glass construction element. Presented are the current procedures in the design of load-bearing glass construction elements.\ud
In the introductory part of the thesis is presented the history of glass and glass features. Followed by an overview of the chemical and physical properties of glass, and the production of glass. Later, I focused on the current standards, and calculations in the use of glass as a carrier material