STRUCTURAL BEHAVIOUR OF MASONRY VAULTS

This paper deals with the modelling and the analysis of masonry vaults. Numerical FEM analyses are performed using LUSAS code. Two vault typologies are analysed (barrel and cross-ribbed vaults) parametrically varying geometrical proportions and constraints. The proposed model and the developed numerical procedure are implemented in a computer analysis. Numerical applications are developed to assess the model effectiveness and the efficiency of the numerical procedure. The main object of the present paper is the development of a computational procedure which allows to define 3D structural behaviour of masonry vaults. For each investigated example, the homogenized limit analysis approach has been employed to predict ultimate load and failure mechanisms. Finally, both a mesh dependence study and a sensitivity analysis are reported. Sensitivity analysis is conducted varying in a wide range mortar tensile strength and mortar friction angle with the aim of investigating the influence of the mechanical properties of joints on collapse load and failure mechanisms. The proposed computer model is validated by a comparison with experimental results available in the literature

COMPUTATIONAL SIMULATIONS FOR HOMOGENIZATION OF MASONRY STRUCTURES

In this paper proposed the application of two-parameters damage model, based on non-linear finite element approach, to the analysis of masonry panels. Masonry is treated as a homogenized material, for which the material characteristics can be defined by using homogenization technique. The masonry panels subjected to shear loading are studied by using the proposed procedure within the framework of three-dimensional analyses. The nonlinear behaviour of masonry can be modelled using concepts of damage theory. In this case an adequate damage function is defined for taking into account different response of masonry under tension and compression states. Cracking can, therefore, be interpreted as a local damage effect, defined by the evolution of known material parameters and by one or several functions which control the onset and evolution of damage. The model takes into account all the important aspects which should be considered in the nonlinear analysis of masonry structures such as the effect of stiffness degradation due to mechanical effects and the problem of objectivity of the results with respect to the finite element mesh. Finally the proposed damage model is validated with a comparison with experimental results available in the literature

Reinforced Concrete Floors in Historic Buildings from the Beginning and the Middle of the 20th Century - Examples of Structural Strengthening in the Process of Revitalization

The paper presents a historical outline of structural solutions of reinforced concrete floors from the turn of the 19th and 20th centuries to the half of the 20th century in the Lower Silesia region of Poland. It is based on the analysis of archival documentation and expert research carried out during the design of the revitalization of historic public and industrial buildings. The structural typology of some simple RC floors slabs used in that time of introduction of concrete into construction life as well as constructional solutions of buildings erected in western Poland in those days are presented. Nowadays, while some of these buildings undergo refurbishment process to adapt them to new functional aims these RC floors have to be strengthened using different methods, depending on the assessment results. In some of the presented design study cases assessed technical state and load bearing capacity of floors ensure the possibility of their further use without the need for significant reinforcements, except for the need for surface material repairs. However, in some cases due to concrete deterioration processes and loss of its durability, despite necessity of material renovation, structural strengthening methods needed to be applied. For example, increasing the load bearing capacity of floors by making additional concrete layers cooperating with the existing reinforced concrete slab or by changing the static scheme by making new supports up to the complete replacement of floors (not only concrete ones) with modern, concrete rib-andbeam or composite ones were considered

Technological Advances and Trends in Modern High-Rise Buildings

The purpose of this paper is to provide structural and architectural technological solutions applied in the construction of high-rise buildings, and present the possibilities of technological evolution in this field. Tall buildings always have relied on technological innovations in engineering and scientific progress. New technological developments have been continuously taking place in the world. It is closely linked to the search for efficient construction materials that enable buildings to be constructed higher, faster and safer. This paper presents a survey of the main technological advancements on the example of selected tall buildings erected in the last decade, with an emphasis on geometrical form, the structural system, sophisticated damping systems, sustainability, etc. The famous architectural studios (e.g., for Skidmore, Owings and Merill, Nikhen Sekkei, RMJM, Atkins and WOHA) that specialize, among others, in the designing of skyscrapers have played a major role in the development of technological ideas and architectural forms for such extraordinary engineering structures. Among their completed projects, there are examples of high-rise buildings that set a precedent for future development

The Modern Trend of Super Slender Residential Buildings

The purpose of this paper is to present a new skyscraper typology which has developed over the recent years – super-tall and slender, needle-like residential towers. This trend appeared on the construction market along with the progress of advanced structural solutions and the high demand for luxury apartments with spectacular views. Two types of constructions can be distinguished within this typology: ultra-luxury super-slim towers with the exclusivity of one or two apartments per floor (e.g. located in Manhattan, New York) and other slender high-rise towers, built in Dubai, Abu Dhabi, Hong Kong, Bangkok, and Melbourne, among others, which have multiple apartments on each floor. This paper presents a survey of selected slender high-rise buildings, where structural improvements in tall buildings developed over the recent decade are considered from the architectural and structural view

Dynamic Diagnostic Tests and Numerical Analysis of the Foundations for Turbine Sets

This paper shows current trends in testing and numerical analysis of dynamic loading in relation to a real frame foundation for a turbogenerator set. The analysis of the machine’s foundations, which are subjected to static and dynamic loads, is a complex problem combining the issues of geotechnics, structural engineering, and vibration theory. The authors present a case study of the assessment of the foundation’s technical condition. The main objective of this study is to perform and compare experimental and numerical dynamic analysis which includes the measurement of the acceleration, speed, and amplitude of the natural vibrations of the foundation during the operational speed of the turbogenerator. In addition, auxiliary material tests were carried out to fully diagnose the foundation and obtain the material properties required for the numerical analysis. They included both destructive and non-destructive of concrete strength, the evaluation of the degree of its carbonation, and the scanning of the reinforcement distribution. The research presented in the paper is intended to facilitate the preparation of appropriate data for the design of the foundation renovation and strengthening

Adaptation of a Mid-Nineteenth Century Representative University Building to Office Functions

The rehabilitation of historical buildings plays an important role in enhancing the sustainable built environment of a city. Re-use of old buildings when adapting them to new functions has become a common way to protect the significance of historical buildings and keep them for future generations as examples of the achievements of former architects and construction masters. Issues connected with the adaptation of an old university three-story building from 1866 that has exceptional artistic qualities is the subject of the analysis presented in this paper. Originally, the building was multifunctional, and intended for the activities of various university units. During the II World War, the main body of the building was seriously damaged. After the war, the building was reconstructed using the current building materials and construction solutions, and was handed over to the Medical Department of Wroclaw University. The building is now undergoing renovation, the purpose of which is to change its function into an office building. The greatest value of the building is its façade - with excellent proportions - which perfectly fits into the spatial context and the development of this part of the city. For this reason, the preservation of the building's main structure was the most important aspect of the renovation design process. The paper presents the results of the assessment of the building’s technical state, analysis of the planned functional changes and renovation ideas, and finally, a description of the structural and constructional solutions adopted to solve the problems occurring during the renovation works

SolarMax Wireless Gateway Device [wireless solar panel control]

The wireless gateway device (WGD) is a system capable of acquiring status information from a solar panel charge controller using either onboard physical button inputs in realtime, or by viewing a log file generated by the device. Initially, in Tier 1, the WGD will be autonomously acquiring status data over a wireless link then dumping that information to an SD card. In further tiers of development, a user will be able to access the log data via TCP/IP over the internet