El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / Since the last decade there is an important increase of high-rise buildings in Peru, especially in urban areas. Therefore, it is necessary to assess if the Peruvian Seismic Code is applicable for this type of buildings which have long natural periods as their main characteristic. The main objective of this article is to compare the results of the base shear and story drift ratios of Peruvian seismic design code E.030 with those of the ASCE 7-16 standard to the case of high-rise buildings, this due to the fact that there is limited information for tall buildings in Peru or comparison between national or international code for this type of structures. These high rise buildings have square and rectangular plan floors. Half of them have moment frames and reinforce concrete slab around the rigid core and the others have post-tensioned slab as their vertical load resisting system and central core walls with peripheral columns as the lateral force resisting system. Hence, the response spectrum analysis (RSA) is carried out for every case of the four tall buildings with different configurations using both seismic codes. Then results are compared with the linear response history analysis (LRHA) considering five Peruvian ground motions records, which were scaled to 0.45g PGA. It was verified that generally both the base shear and the interstory drifts calculated using ASCE7-16 are less than that obtained with the seismic code E.030.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第21364号 / 工博第4523号 / 新制||工||1704(附属図書館) / 京都大学大学院工学研究科建築学専攻 / (主査)教授 西山 峰広, 教授 竹脇 出, 准教授 倉田 真宏 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Yes / Reinforced piled embankment technique is becoming increasingly utilised for the construction over soft grounds due to its efficiency on reducing potential settlement, speed of construction and associated cost. Most of previous studies focused on developing understanding for the behaviour of thick embankments that are loaded with a static surcharge load. Data for the behaviour of shallow piled embankments under cyclic loadings are scarce. In this study, an experimental programme was undertaken using a fully instrumented testing rig to generate data and improve our understanding for the behaviour of unreinforced and reinforced shallow piled embankments subject to monotonic and cyclic loadings that were applied over a predetermined area of the embankment. The experimental results showed that collapse of soil arching is imminent and occurs during the first few cycles of load. However, regain of strength and recovery of the arching effect was observable during further stages of cyclic loadings due to densification of the embankment material and deformation of the soft subsoil. Inclusion of reinforcement layers was found to enhance the performance of load transfer mechanisms by concentrating stresses on pile caps. The results clearly showed a significant reduction in surface settlement, soft subsoil settlement and heaving with increasing the number of reinforcement layers.

The controlled rocking heavy timber wall (CRHTW) is a high-performance structural solution that was first developed in New Zealand, mainly considering Laminated Veneer Lumber (LVL), to resist high seismic loads without sustaining structural damage. The wall responds in bending and shear to small lateral loads, and it rocks on its foundation in response to large seismic loads. In previous studies, rocking has been controlled by both energy dissipation elements and post-tensioning, and the latter returns the wall to its original position after a seismic event. The controlled rocking response avoids the need for structural repair after an earthquake, allowing for more rapid return to occupancy than in conventional structures. Whereas controlled rocking walls with supplemental energy dissipation have been studied before using LVL, this thesis proposes an adapted CRHTW in which the design and construction cost and complexity are reduced for low-to-moderate seismic hazard regions by removing supplemental energy dissipation and using cross-laminated timber (CLT) because of its positive economic and environmental potential in the North American market. Moreover, whereas previous research has focussed on direct displacement-based design procedures for CRHTWs, with limited consideration of force-based design parameters, this thesis focusses on force-based design procedures that are more common in practice. A design and analysis process is outlined for the adapted CRHTW, based on a similar methodology for controlled rocking steel braced frames. The design process includes a new proposal to minimize the design forces while still controlling peak drifts, and it also includes a new proposal for predicting the influence of the higher modes by referring to previous research on the capacity design of controlled rocking steel braced frames. Also, a numerical model is outlined, including both a baseline version and a lower-bound model based on comparison to experimental data. The numerical model is used for non-linear time-history analysis of a prototype design, confirming the expected performance of the adapted CRHTW, and the model is also used for incremental dynamic analyses of three-, six-, and nine-storey prototypes, which show a low probability of collapse. / Thesis / Master of Applied Science (MASc) / The controlled rocking heavy timber wall (CRHTW) is a high-performance structural solution that was developed to resist high seismic loads without sustaining structural damage. The wall responds in bending and shear to small lateral loads, and it rocks on its foundation in response to large seismic loads. In previous studies, rocking has been controlled by both energy dissipation elements and post-tensioning; the latter returns the wall to its original position after a seismic event. This controlled rocking behaviour mitigates structural damage and costly repairs. This thesis explores the value of an adapted CRHTW in which the design and construction costs and complexity are reduced for low-to-moderate seismic hazard regions by using post-tensioning but no supplemental energy dissipation. A design and analysis process is outlined; numerical analysis confirms the expected performance of the adapted CRHTW; and the system is shown to have a low probability of collapse.

No description available.

No description available.

<p dir="ltr">Post-tensioned concrete is a popular structural system in modern bridge design, allowing for longer bridge spans and the construction of curved, spliced, and segmental girders. When designed and constructed properly, post-tensioned concrete can offer improved durability over reinforced concrete as it is more resistant to cracking. However, corrosion of prestressing strands can compromise the integrity of post-tensioned construction. Grouting has been the primary method of providing corrosion protection to the prestressing strands. However, grouting of tendons presents numerous limitations and results in multiple problems in practice. As a result, there has been increased interest in the use of unbonded tendons. Corrosion protection can still be achieved in unbonded tendons through the use of flexible fillers such as grease and microcrystalline wax. Limited research has been conducted on unbonded tendons, and no known research exists regarding the behavior of unbonded tendons subject to torsion. The objective of this research was to investigate the torsional behavior and strength of unbonded post-tensioned bridge girders. The scope of work included testing six specimens to investigate the difference in behavior between bonded and unbonded tendons as well as the influence of internal versus external ducts. The influence of transverse reinforcement was also considered.</p>

La corrosion dans le béton précontraint est considérée parmi les pathologies les plus dangereuses dans le secteur du génie civil. En effet ce phénomène se caractérise par la gravité de ses conséquences économiques et sécuritaires. L’objectif de ce travail consiste à évaluer l’efficacité d’un inhibiteur à base de phosphates Na3PO4.12H2O contre la corrosion des aciers de précontrainte. L’étude a été d’abord menée en milieu synthétique simulant le béton chloruré sur des armatures tendues à 80% Rm, puis d’une part sur des éprouvettes en mortier précontraint conçues à l’échelle laboratoire, et d’autre part en utilisant la technique de cellule de diffusion pour tester l’efficacité de l’inhibiteur à long terme. Les résultats issus de l’étude réalisée dans le milieu simulant ont révélé que la présence des phosphates entraine l’augmentation du seuil critique d’amorçage de corrosion localisée R=[Cl-]/[OH-] jusqu’à la valeur de 5 au lieu de 0,4. Ceci semble être dû à deux actions inhibitrices des phosphates à savoir : la stabilisation de la couche protectrice à base d’oxyde de fer et la formation de composés phosphatés très peu solubles qui bloquent les sites anodiques actifs, augmentant ainsi la résistance de l’acier à la corrosion localisée. L’emploi de Na3PO4.12H2O en tant qu’adjuvant diminue légèrement la résistance à la compression du mortier. Cependant les composés phosphatés provenant de la réaction de l’inhibiteur avec les hydrates de ciment colmatent les pores du mortier et freinent la diffusion des chlorures. Ceci améliore le comportement à la corrosion des armatures enrobées de mortier précontraint. Enfin, lorsque le triphosphate de sodium est utilisé comme inhibiteur migrateur ou comme moyen de prétraitement des armatures, la technique de la cellule de diffusion a montré son efficacité à long terme, grâce à l’augmentation de la période précédant l’amorçage d’une corrosion localisée, où l’armature est en état passif. / Corrosion in prestressed concrete is considered among the most dangerous pathologies in the civil engineering sector. Indeed, this phenomenon is characterized by the seriousness of its economic and security consequences. The objective of this work is to evaluate the efficiency of a phosphate based inhibitor Na3PO4.12H2O against the corrosion of prestressing steels. The study was first conducted on wires tensioned at 80% Rm and immersed in simulating concrete pore solution. Then it concerned, on one hand, prestressed mortar specimens designed on a laboratory scale and, on the other hand, the long term efficiency of the inhibitor using diffusion cell technique. The results obtained from the study carried out in the concrete simulating medium revealed that the presence of the phosphates causes the increase in the critical threshold of localized corrosion initiation R = [Cl -] / [OH-] up to the value of 5 instead of 0.4. This seems to be due to two phosphate inhibiting actions, namely: the stabilization of the iron oxide protective layer and the formation of very insoluble phosphate compounds which block the active anodic sites, increasing prestressing steel resistance to localized corrosion. The use of Na3PO4.12H2O as an additive slightly reduces the compressive strength of the mortar. However, phosphate compounds resulting from the reaction of the inhibitor with the cement hydrates clog the pores of the mortar and slow down the diffusion of the chlorides. This improves the corrosion behavior of prestressed mortar reinforcement. Finally, when sodium triphosphate is used as a migratory inhibitor or as a means of steel reinforcement pretreatment, the diffusion cell technique has shown its long-term efficiency, thanks to the increase of the period preceding the initiation of a localized corrosion, where the reinforcement is in a passive state.

Les travaux présentés dans cette thèse contribuent au développement du contrôle non destructif des conduits de précontrainte extérieure dans les ouvrages d'art. Une sonde capacitive a été développée pour ausculter ces conduits. L'objectif est d'en améliorer le diagnostic.Dans un premier temps, une cellule de mesure en transmission coaxiale a été développée pour caractériser les matériaux présents dans le conduit sur la bande de fréquence 50 MHz - 1 GHz. Le ciment, les produits de la ségrégation du ciment et la cire d'injection ont été étudiés.La deuxième partie du travail exploite ces résultats dans une modélisation directe du problème global. Une étude paramétrique nous a permis de proposer une méthode d'estimation de l'épaisseur de vide à l'intérieur du conduit à partir des signaux délivrés par la sonde, qui a pu être validée sur une maquette de conduit. A partir de ces résultats sont proposées plusieurs améliorations du dispositif visant à l'obtention de signaux plus riches issus des capteurs, afin de pouvoir estimer un plus grand nombre de paramètres. / The work presented in this report contributes to the development of Non Destructive Evaluation of the external post-tensioned ducts in bridges. A capacitive probe has been developed for bridge monitoring applications. The aim of this work is to improve its diagnostic.In a first step, a coaxial transmission line was developed to characterize the materials involved in the duct over the frequency range 50 MHz - 1 GHz. The cement grout, segregation products of the cement grout and the injection wax were studied.In the second part of this work the previous results are used in the modelling of the devices. A parametrical study has shown the ability to get from the signals an estimate of the thickness of the void in the duct. This estimation method has been validated using a laboratory duct. Further, several improvements of the probes are proposed to get signals containing more information in order to get a better estimation of the target parameters.

[pt] Nesta tese relato aplicações das estruturas leves de bambu. Na primeira parte do trabalho trato da história passada e da história contemporânea do emprego no mundo das estruturas estabilizadas pela união entre bambus e cabos. Os objetivos dessas estruturas, alguns dos seus precursores e suas experiências são citadas. O uso popular de estruturas feitas com esses materiais é tornado manifesto com imagens e textos referentes. A seguir tratamos dos modos artesanais de suas feituras e da passagem de sua técnica para espaços de convivência sendo enfatizado o efeito cultural do trabalho amoroso e detalhado de transmitir a maneira de fazer os objetos. Na segunda parte do trabalho apresento o estado da Arte no Laboratório de Investigação em Living Design (LILD), do Departamento de Artes e Design (DAD) da PUC-Rio, no campo destas estruturas. São narradas atividades de passagem das técnicas em 3 (três) comunidades situadas no estado do Rio de Janeiro: a) na aldeia dos professores indígenas KUAA MBO E Guarani em Parati, no LILD e no CENAM (Centro de Acolhida Missionária); b) no Parque Estadual da Ilha Grande (PEIG), na Escola Municipal Brigadeiro Nóbrega; c) na Escola de Circo no espaço Crescer e Viver com o grupo Nós nos Nós - tragédias e comédias aéreas. Relato também a metodologia utilizada em sua dinâmica as suas relações e vínculos, com a graduação e pós-graduação em Design e com outros setores da Universidade. São narradas a passagem das técnicas, a elaboração e uso dos protótipos. Distingo as conexões utilizadas nestas estruturas feitas com bambus e cabos, chamadas do tipo vigas recíprocas, popularmente chamadas de giro, que vem sendo utilizadas nacionalmente e internacionalmente. / [en] In this thesis report applications of lightweight structures with bamboo. In the first part of the tract of past history and contemporary history of employment in the world of structures stabilized by the union of bamboo and cables. The objectives of these structures, some of its precursors and their experiences are cited. The popular use of structures made with these materials is made manifest in images and texts related. Below we deal with the ways of their craft and making the passage of his technique for living space and emphasized the cultural effect of loving work and detailed way forward to make the objects. In the second part of the present state of the art in the Research Lab in Living Design (Lild), Department of Art and Design (DAD) of PUC-Rio, in the field of these structures. Activities are recounted in passing techniques in 3 (three) communities located in the state of Rio de Janeiro: a) teachers in the village of indigenous Guarani KUAA MBO E in Parati, and Lild CENAM (Center Welcoming Mission), b)State Park of Ilha Grande (Peig), the Municipal School Brigadier Nóbrega c) at Circus School Living and Growing in space with the group We We - air tragedies and comedies. Account also the methodology used in its dynamics and its relations ties with undergraduate and graduate design and other sectors of the University. Are told the passage of the techniques, the development and use of prototypes. Distinguish the connections used in these structures made of bamboo and wire, called the reciprocal type beams, popularly called spin, which is being used nationally and internationally.