Biodeterioration is the leading cause of failure in buildings. Organic materials, key components of our built infrastructure, are particularly vulnerable to biotic attack (i.e. fungal growth) and can suffer from pre-mature failure. These failures are responsible for billions of dollars of direct damage to wooden structures in Canadian buildings. The impacts of failure can range from mild surface disfigurement, allergic reactions, mycoses, to direct life-safety concerns from compromised building structures. These impacts all have different failure modes and it is therefore prudent to consider how these failures manifest. The limit state design framework is an approach used by engineers to describe the risks of failure. It defines the probabilistic failure envelope of an inherent resistance being exceeded by a given load. The competing loads and resistances, in this case, consist of the fungal growth potential versus the intrinsic resistance of the substrate. Another key feature of limits state design is that it describes differing thresholds of failure depending on the potential impacts. This framework is desirable in application for biodeterioration in buildings. However, prior attempts to adopt these concepts into biodeterioration models have met with limited success. This dissertation is the first to effectively apply a limit state design framework to biodeterioration by considering two key states: serviceability limit state (i.e. surface fungal growth), and ultimate limit state (i.e. incipient decay). First, a database of fungal deterioration was created using Penicillium chrysogenum and Gloeophyllum trabeum fungi inoculated on jack pine (Pinus banksiana) prisms. These prisms were careful controlled for both moisture content and temperature, while minimizing ambient contamination. Photo documentation using a 20x USB microscope permitted evaluation of the surface disfigurement of the ascomycete fungus (serviceability state), and non-destructive flexural testing permitted the identification of incipient decay with the wood rotting basidiomycete (ultimate limit state). A serviceability limit state model was created using a population growth equation to describe the probability of detecting fungal growth as a function of substrate type (heartwood or sapwood), moisture content, temperature, and time. The model was contrasted with empirical tests on a mouldy roof in Vancouver, BC, and shows promising results that surpass the limitations of competing mould models. The method to develop the ultimate limit state model has been delineated in this dissertation, but further work is required. Future scopes of work are provided to address the limits and areas of uncertainty revealed by this research, but the results can help reshape the narrative of biodeterioration risk assessments for the built environment. / Graduate

The aim of this study is designing steel structures with the same geometry, material and soil conditions but in the different countries, and comparing these designs in terms of material savings. According to three steel building codes, namely TS 648, LRFD, Eurocode 3, same structures with various stories (2, 4, 6, 8, and 10) are analyzed and designed. To calculate the design loads, Turkish Earthquake Code 2007 and Turkish Standard 498 (Design Load for Buildings) are utilized when TS 648 is applied. When LRFD is concerned, ASCE Standard 7-05 (Minimum Design Loads for Buildings and Other Structures) and AISC Standard 341-05 (Seismic Provisions for Structural Steel Buildings) are used for calculation of the design loads and earthquake loads. When Eurocode 3 is applied, Eurocode 8 (Earthquake Resistance Code), Eurocode 1 (Actions of Structures) and Eurocode-EN 1990 (Basis of Structural Design) are used in order to determine the design and earthquake loads. Weight of steel used on 1 m&sup2 / is almost the same for procedures of LRFD and EC3. It is important to note that those procedures consider 20 % of material saving compared to TS648.

This Ph.D. thesis represents a summative report detailing research processes and outcomes from investigating the ultimate and serviceability limit state short- and long-term behaviour and design of timber-concrete composite floors. The project enables the realization of a semi-prefabricated LVL-concrete composite floor system of up to 15 m long using 3 types of connection. Design span tables which satisfy the ultimate and serviceability limit state short- and long-term verifications for this system form the novel contribution of this thesis. In quantifying the behaviour of timber-concrete composite floors, 5 different experimental phases have been carried. 9 major achievements in meeting 9 sub-objectives have been concluded: 1) Three best types of connection system for timber-concrete composite floors have been identified; 2) The characteristic strength and secant slip moduli for these connections have been determined; 3) The short-term behaviour of the selected connections defined by their pre- and post-peak responses under collapse load has been established; 4) An analytical model for the strength evaluation of the selected connections based on the different possible modes of failure has been derived; 5) Easy and fast erected semi-prefabricated timber-concrete composite floor has been proposed; 6) The short-term ultimate and serviceability limit state behaviour of timber-concrete composite floor beams under collapse load has been investigated; 7) The long-term behaviour of chosen connections defined by their creep coefficient has been determined; 8) The long-term behaviour of timber-concrete composite floor beams under sustained load at serviceability limit state condition has been investigated; and 9) Design example and span tables for semi-prefabricated timber-concrete composite floors that satisfy both the ultimate and serviceability limit state in the short- and long-term using the gamma-method have been developed.

Traditionally, flexible pavement design relies on past experience and semi-empirical methods developed through a combination of element testing and modelling. Element testing in this area especially, has centred on the performance of clean sands. This is in conflict with actual practice where a wide range of fines and soil gradations could be present in a real-world project. This research investigates the characteristics of natural sands and examines the influence of these marginal materials in pavement design using element testing and controlled modelling of an actual flexible pavement system. The element tests concentrated on separate, natural soils sourced from Kazakhstan which had similar mineralogy, but varying amounts of fines. One of the key parameters examined was equivalent void ratio and its efficiency to account for the behaviour change in granular materials which comes from increased fines content. Starting with monotonic triaxial results combined with strength-dilatancy methods it was shown that prediction of shear strength in a silty-sand could be improved by 13%. Incorporating this finding into repeat load triaxial tests, the transitions between elastic, plastic, and ratcheting failure behaviours (i.e. shakedown boundaries), commonly used to help predict the lifespan of a flexible pavement, were examined. It was seen that cycling a silty-sand, the stress path and yield surface could change depending on the fines content. The Cambridge Airfield Pavement Tester (APT) was designed and constructed to measure permanent subgrade deformation resulting from various surface loads. The number of input variables required to design flexible pavements is one of the most frequently stated problems in the field; variation of aircraft types, environmental conditions, and materials makes mechanistic design of the soil foundation problematic. Accordingly physical pavement modelling continues to be the only experimental method that allows input parameters and material characteristics to be examined simultaneously. Digital image correlation (DIC) was incorporated into the system; the first time this technology has been used in flexible pavement research. A Null Pressure System was also installed to measure soil stress distributions. It was observed that the critical failure mechanisms for thin and thick surficial layers are different, resulting in changes in the rates of surface rutting. Finally, by combining element and APT results, knowledge of the causal relationships between subsurface deformation and failure mechanisms in flexible pavement were advanced. In-situ soils, which are frequently incorporated into subgrade designs, were found to have a substantial role in the serviceability of the pavement. Correlations between element tests and APT results highlighted the complicated loading and boundary conditions present in a pavement.

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The partial safety factor method is the main safety concept applied across structural design standards. This method is also presented in EN-1990 as the basis of structural design in Europe. In the review of this code for the new generation of Eurocodes, analysis of the partial safety factor method seems necessary. The origin of the partial safety factor method is related to probabilistic methods and reliability analysis. Therefore, the latter is selected as tools for the evaluation of the partial safety factor method in the EN-1990 framework. Consequently this research begins with an explanation of the background of partial safety factor methods and reliability analysis. Different aspects of this safety concept are investigated through this study. The analysis strategy is based on the study of partial safety factor method according to the different part of EN-1990. The research is divided into two main parts, according to the basic components of limit state functions: load and resistance. Aspects related to loading are investigated first. The available load combinations and the recommended partial factors are investigated based on their reliability levels. The load combinations are compared with each other according to the sustainability of their design. An increased factor for the application of snow load is proposed to overcome safety problems related to snow load on structures. Consequently, a proposal for simplifying these load combinations is offered and verified according to reliability analysis. In the final step, regarding the load’s partial factors, a method of calibration is proposed, based on Monte Carlo reliability analysis. Afterwards, the aspects related to the resistance are analyzed. Resistances depend mostly on experimental data. Therefore, the relationship between the partial safety factor of resistance and test numbers is investigated. A probabilistic analysis based on Annex D of EN-1990 is then applied to calculate the model uncertainty partial factor and the resistance partial factor for a database from masonry shear walls. A comparison is made to show the influence of different way of partial safety factor utilization in a limit state function.:1 Introduction 2 Partial safety factor method and EN-1990 3 Reliability analysis 4 Load combinations and partial safety factors 5 Resistance partial safety factor 6 Summary and outlook

Nowadays / design, fabrication and erection of steel structures can be taken place at different locations as a result of rapid globalization / owners may require the use of widely accepted steel design codes. Therefore, engineers are faced with the challenge of being competent with several design specifications for a particular material type. AISC-360 and EC3 are widely accepted steel structure design specifications that utilize limit state principles with some similarities and differences in application. Hereby a study has been undertaken to put together the nominal strength expressions presented in both AISC-360 and EC3 codes in a single document, to identify the similarities and the differences in calculated strengths and to facilitate rapid learning of either of the specifications with prior knowledge of the other. Because of the wide scope of specifications, only fundamental failure modes are considered in this thesis. Resistance equations are directly compared with each other wherever possible. For cases where the treatment of specifications is entirely different, representative members were considered for comparison purposes.

The thesis deals with the design and assessment of monolithic reinforced concrete structures tanks and wastewater treatment plants in accordance with applicable standards and drafting drawings. The tank is divided into individual solved parts: base plate, walls and ceiling plate. These parts are designed according to the ultimate limit states and serviceability. Resolves an assessment of the foundation structure according to the second geotechnical categories.

Subject of the dissertation is a probability analysis on creation of embankment subsoil filtration deformations. Out of the broad topic of filtration deformations, the dissertation is focused at initiation of the process. At this phase, the overlying layers downstream of levee get uplifted, and eventually get breached. The process of downstream subsoil failure probability estimation is formulated using mathematical and statistical modelling. Within the scope of parametrical study the suggested method is applied onto a test environment. Results of the probability estimation are compared with results obtained using Limit state design method. The results of stochastic modelling can be used for improvement of Limit state design method precision.

This thesis deals with the design and static assessment of a concrete part of a sewage treatment plant. Specifically, the calculation and assessment of the base plate, external walls, internal walls and ceiling slabs, elaboration of shape and reinforcement drawings of selected structural element. The concrete part of the Sewage disposal plant is all below ground level. Static system and the calculation of internal forces was carried out in Scia Engineer 2011 - student version.