La thèse s’inscrit dans un axe de recherche visant à améliorer l’analyse par éléments finis (EF) des structures aéronautiques soumises au crash et à l’impact. L’étude s’intéresse, en particulier, à la modélisation des assemblages rivetés dans les calculs de structures, qui sont des zones de concentrations de contraintes propices à l’initiation de ruptures. Si la rupture de la fixation est maîtrisée, les modes de rupture dus aux perforations sont, quant à eux, difficiles à simuler dans un calcul sur structure complète. Afin de prendre en compte avec précision l’influence des perforations sur la réponse mécanique de telles structures, un super-élément perforé à 8 nœuds a été formulé lors d’une précédente thèse. Cependant, sa frontière interne est analytique et libre de chargement, ce qui rend difficile la connexion avec un élément rivet, et donc la modélisation de l’assemblage. L’étude proposée ici consiste donc à développer un super-élément perforé qui soit capable de tenir compte de l’influence de la perforation sur les champs mécaniques, d’une part, et qui soit formulé de façon à rendre possible l’interaction avec un macro-élément rivet, d’autre part. / The thesis is made in a context which consists in improving the finite element (FE) analysis of full-scale aircraft structures subjected to crash and impact loadings. The study is focused, in particular, on the rivetedassemblies modeling in structural computations, which are stress concentrations areas where ruptures initiation can occur. If the fastener rupture is mastered, the rupture modes due to perforations are, however, difficult to simulate in a complete structure computation. In order to accurately take into account the perforations influence on the mechanical response of such structures, a perforated super-element featuring 8 nodes have been formulated in a previous thesis. Nevertheless, its internal boundary is analytic and free of loads, which makes difficult the connection with a rivet element, and consequently the assembly modeling. The study proposed here consists in the developement of a perforated super-element which is, on the one hand, able to take into account the perforation influence on the mechanical fields, and which is, on the other hand, formulated such as the interaction with a rivet macro-element is possible.

Urban construction sites require strict control of their environmental impact, which, for vibratory sheet pile driving, can include damage to nearby structures due to ground vibrations. However, the lack of knowledge concerning the generation of soil vibrations makes the prediction of ground vibration levels difficult. This MSc. thesis in particular, focuses on a crucial link in the vibration transfer chain: the sheet pile – soil interface, which is also one of the least documented. The aim of this thesis is first, to carry out a full-scale field test consisting in the monitoring of sheet pile and ground vibrations during sheet pile vibratory driving. And second, to analyze a selected portion of the collected data with focus on the sheet pile – soil vibration transfer. Both aspects of the thesis work aim, more generally, to contribute to the understanding of ground vibration generation under vibratory sheet pile driving. The full-scale field study was performed in Solna in May 2013. It consisted in the vibratory driving of seven sheet piles, out of which three were fitted with accelerometers. During the driving, ground vibrations were measured by accelerometers, the closest ones placed only 0.5 m from the sheet pile line. The design and installation of the soil instrumentation was innovative in as much as accelerometers were not only set on the ground surface but also at three different depths (~ 3 m, 5 m and 6 m). The analysis presented in this thesis is primarily a comparison between sheet pile vibrations and ground vibrations measured 0.5 m from the sheet pile line. The principal aspects considered in the comparison are: the influence of penetration through different soil layers, the sheet pile – soil vibration transfer efficiency, the frequency content of sheet pile and soil vibrations, and differences between toe- and shaft-generated vibrations. The main conclusions from this study are:  Most of the vibration loss occurs in the near field: 90-99% of the sheet pile vibration magnitude was dispersed within 0.5 m from the driven sheet pile. Moreover, the sheet pile – soil vibration transfer efficiency was reduced for higher sheet pile acceleration levels and higher frequencies.  The soil characteristics strongly influence the sheet pile vibration levels. A clear distinction could be made between "smooth" and "hard" driving, the latter being associated with an impact situation at the sheet pile toe.  The focus of ground vibration studies should not only be the vertical vibrations. Indeed, the ground vibrations’ horizontal component was found to be of the same or even higher magnitude than the vertical component.

The Utah Department of Transportation (UDOT) is interested in the application of rehabilitation techniques to strengthen their AASTHO prestressed bridge girders for shear. Utah's bridges are exposed to deterioration from rain, snow, and the introduction of salt for ice removable. This requires innovative rehabilitation techniques to address the deteriorations of their highway bridges, especially the ends of bridge girders where water and salt are more common due to construction joints. Carbon Fiber Reinforced Polymers (CFRP) are becoming more prevalent as a tool in highway bridge rehabilitation. This research investigates the application of various CFRP systems that can be used as shear reinforcement for prestressed concrete girders. The experimental program involved full-scale destructive testing of six 40-year-old, AASHTO prestressed I-girders that were salvaged from the 45th South/I-215 bridge in Salt Lake City, Utah. The testing involved retrofitting five of the girders with various configurations of CFRP fabric. Based on the initial tests, the most effective configuration was then applied to another set of I-shaped concrete girders for verifications. After the experimental testing, two analytical models developed for predicting the additional shear contribution of the CFRP reinforcement were compared with the measured results from the experimental program. After testing and comparisons, a CFRP reinforcement configuration and theoretical model was selected as a reliable and effective method for application of external shear reinforcement of AASHTO prestressed I-shaped girders.

Nowadays, many different efficient solutions are being studied to solve engineering problems. Inside this group of solutions we can find the Soil Steel Composite Bridges (SSCB) as an alternative to traditional bridges. SSCB are being used more often every day and they are showing themselves as competitive structures in terms of feasibility and constructability. This project was started to achieve two different goals. The first one was to create a general database of SSCB including few selected tests all around the world and the second one was to compare and discuss full scale tests using the Pettersson-Sundquist design method. To create the database and the following comparisons, twenty-five different full scale tests were used. From this tests all the necessary information was extracted and used to create the database. After creating the database, the project continued with the discussion and comparison of the full scale tests. Specifically those discussions and comparisons were related to the resistance of the soil (the soil modulus) used in the construction of the SSCB. All the values of the different soil modulus of each full scale test used in the comparisons were calculated using the Swedish Design Manual (SDM). Two different types of soil modulus were calculated in this project using SDM, ones are the soil modulus back calculated using the values reported from the live load tests performed on the culverts and the others are theoretical soil modulus calculated using the detailed information of the soil. The report continues with the explanation of the different conclusions ended up with during this project. It can be highlighted within this group of conclusions, the one related to the importance of reporting all the necessary information from the full scale tests including the soil parameters, the measures of the culvert, the cross sectional parameters and the vehicle dimensions among others. Another important conclusions are the effect of using the slabs over the top of the culvert and how it would effect to the sectional forces over the culvert and also the limitations using method B of the SDM regarding the type of soil used as backfilling Finally, the project finishes explaining some proposals for future research about other fields of the study of SSCB.

Although it is well established that spacing of piles within a pile group influences the lateral load resistance of that group, additional research is needed to better understand trends for large pile groups (greater than three rows) and for groups in sand. A 15-pile group in a 3x5 configuration situated in sand was laterally loaded and data were collected to derive p-multipliers. A single pile separate from the 15-pile group was loaded for comparison. Results were compared to those of a similar test in clays. The load resisted by the single pile was greater than the average load resisted by each pile in the pile group. While the loads resisted by the first row of piles (i.e. the only row deflected away from all other rows of piles) were approximately equal to that resisted by the single pile, following rows resisted increasingly less load up through the fourth row. The fifth row consistently resisted more than the fourth row. The pile group in sand resisted much higher loads than did the pile group in clay. Maximum bending moments appeared largest in first row piles. For all deflection levels, first row moments seemed slightly smaller than those measured in the single pile. Maximum bending moments for the second through fifth rows appeared consistently lower than those of the first row at the same deflection. First row moments achieved in the group in sand appeared larger than those achieved in the group in clay at the same deflections, while bending moments normalized by associated loads appeared nearly equal regardless of soil type. Group effects became more influential at higher deflections, manifest by lower stiffness per pile. The single pile test was modeled using LPILE Plus, version 4.0. Soil parameters in LPILE were adjusted until a good match between measured and computed responses was obtained. This refined soil profile was then used to model the 15-pile group in GROUP, version 4.0. User-defined p-multipliers were selected to match GROUP calculated results with actual measured results. For the first loading cycle, p-multipliers were found to be 1.0, 0.5, 0.35, 0.3, and 0.4 for the first through fifth rows, respectively. For the tenth loading, p-multipliers were found to be 1.0, 0.6, 0.4, 0.37, and 0.4 for the first through fifth rows, respectively. Design curves suggested by Rollins et al. (2005) appear appropriate for Rows 1 and 2 while curves specified by AASHTO (2000) appear appropriate for subsequent rows.

Studies of seismic and impact loading on foundation piles is an important and a focused interest in the engineering world today. Because of seismic and other natural events are unpredictable, uncontrollable and potentially unsafe it is a vital study to understand the behavior and relationship structures in motion have on there foundation. Statnamic Loading has become a popular method of studying this relationship in a controlled environment. Two groups of 9 and 15 driven hollow pipe piles were tested in saturated clay at the Salt Lake City Airport in July of 2002. The 9-pile group (3x3 configuration) was separated at 5.65 pile diameters and the 15-pile group (3x5 configuration) was separated at 3.92 pile diameters. The testing consisted of five target deflections. Each target deflection consisted of 15 cyclic lateral static loadings and a 16th lateral statnamic load. This study focuses on the statnamic loading. Damping ratios ranged from 23 to 50 percent for the 15-pile group and 29 to 49 percent for the 9-pile group. Both pile groups increased in damping as the deflections increased. The optimized mass in motion for the entire system was found to be roughly 21,000kg for the 15-pile group and 14,000 kg for the 9-pile group. Stiffness for the 15-pile group started at 50kN/mm and ended at 21kN/mm. The 9-pile group ranged from 28kN/mm to 12kN/mm.

This research consists of full-scale shake table tests to investigate liquefaction of sandy soils. Consideration of the potential and consequences of liquefaction is critical to the performance of any structure built in locations of high seismicity underlain by saturated granular materials as it is the leading cause of damage associated with ground failure. In certain cases the financial losses associated with liquefaction can significantly impact the financial future of an entire region. Most liquefaction triggering studies are performed in the field where liquefaction has been previously observed, or in tabletop laboratory testing. The study detailed herein is a controlled laboratory test performed at full scale to allow for the measurement of field-scale index testing before and after cyclic loading. Testing was performed at the Parson’s geotechnical and Earthquake Laboratory at Cal Poly San Luis Obispo on the 1-dimensional shake table with a mounted flexible walled testing apparatus. The testing apparatus, originally constructed for soil-structure interaction experiments utilizing soft clay was retrofitted for the purpose of studying liquefaction. This research works towards comparing large-scale simple-shear liquefaction testing to small-scale simple-shear liquefaction testing of a #2/16 Monterey sand specimen. The bucket top was modified in order to apply a vertical load to the soil skeleton to replicate overburden soil conditions. Access ports were fitted into the bucket top for instrument cable access and to allow cone penetration testing before and after cyclic loading. A shear-wave generator was created to propagate shear waves into the sample for embedded accelerometers to measure small strain stiffness of the sample. Pore-pressure transducers were embedded in the soil sample to capture excess pore water pressure produced during liquefaction. Displacement transducers were attached to the bucket in order to measure shear strains during cyclic testing and to measure post-liquefaction volumetric deformations. The results of this investigation provide an empirical basis to the behavior of excess pore water production, void re-distribution, shear wave velocity, shear strain and cone penetrometer tip resistance of #2/16 Monterey sand before, during, and after liquefaction in a controlled laboratory environment at full-scale.

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