El objetivo principal de la presente investigación es idear un sistema que logre disminuir el costo y el tiempo de elaboración de muros no portantes de albañilería confinada. Para lograrlo se ha diseñado un sistema de bloques de arcilla apilables en seco y autoencajables que cumple con todas las normas imputables. Para determinar el rendimiento del sistema diseñado se fabricaron las piezas y se construyó un muro con medidas típicas. Los resultados para dicho caso de estudio se resumen en un ahorro de 17% en el costo directo (considerando todo el muro en su conjunto) y 76% en el tiempo empleado (solo en el asentado de bloques). / The principal objective of this research is to design a system that manage to reduce the cost and time in the construction of non-structural masonry walls. To achieve this, it has been designed a Mortarless Dry-Stacked Interlocking Masonry Clay Bricks which verifies all the imputable codes. To determine the performance of the system, the bricks were made and a wall with typical measurements was built. The results for this study are 17% of reduction in the direct cost (considering the whole wall) and 76 % less time used (alone in the brick seating). / Tesis

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / The aim of this article is to use artificial neural networks (ANN) to perform the structural design of confined masonry buildings. ANN is easy to operate and allows to reduce the time and cost of seismic designs. To generate the artificial neural network, training models (traditional confined masonry designs) are used to identify the input and output parameters. From this, the final architecture and activation functions are defined for each layer of the ANN. Finally, ANN training is carried out using the backpropagation algorithm to obtain the matrix of weights and thresholds that allow the network to operate and provide preliminary structural designs with a 10% margin of error, with respect to the traditional design, in the dimensions and reinforcements of the structural elements.

The Casimiro Ulloa Hospital is a confined masonry structure more than 60 years old that does not satisfy the requirements of the Peruvian seismic code E.030 and it is located at high seismic zone. Therefore, this hospital is susceptible to collapse and becomes an essential deficient structure. Therefore, the present study is based on a comparative analysis between reinforced concrete wall and CFRP sheets through the nonlinear Push Over method in order to obtain which is the best reinforcement in structural capacity. The reinforcement with eight L-shaped concrete walls of 15 cm thick located at the corners of the structure, increased the strength of the hospital by 115% in longitudinal direction (Axis X) and 108% in transversal direction (Axis Y), and also increased the ductility by 3% and 117% in the directions respectively. The other reinforcement was carried out with CFRP sheets and anchors. The sheets were designed with a width of 9 inches and were placed in an X-shape in the masonry load-bearing walls and the anchors were implemented in the corners of the laminate walls in order to ensure adequate load transfer between the sheets and the surface. This reinforcement increased the strength of the structure by 345% in axis X and 150% in axis Y and increased the ductility by 59% in longitudinal direction and 331% in transversal direction.

The structural damage after the Christchurch earthquake (2011) led to extensively damaged facilities that did not collapse but did require demolition, representing more than 70% of the building stock in the central business district. These severe economic losses that result from conventional seismic design clearly show the importance of moving towards resilience-based design approaches of structures. For instance, special reinforced masonry shear walls (SRMWs), which are fixed-base walls, are typically designed to dissipate energy through the yielding of bonded reinforcement while special detailing is maintained to fulfill ductility requirements. This comes at the expense of accepting residual drifts and permanent damage in potential plastic hinge zones. This design process hinders the overall resilience of such walls because of the costs and time associated with the loss of operation and service shutdown. In controlled rocking systems, an elastic gap opening mechanism (i.e., rocking joint) replaces the typical yielding of the main reinforcement in conventional fixed-base walls, hence reducing wall lateral stiffness without excessive yielding damage. Consequently, controlled rocking wall systems with limited damage and self-centering behavior under the control of unbonded post-tensioning (PT) are considered favorable for modern resilient cities because of the costs associated with service shutdown (i.e., for structural repairs or replacement) are minimized. However, the difficulty of PT implementation during construction is challenging in practical masonry applications. In addition, PT losses due to PT yielding and early strength degradation of masonry reduce the self-centering ability of controlled rocking masonry walls with unbonded post-tensioning (PT-CRMWs). Such challenges demonstrate the importance of considering an alternative source of self-centering. In this regard, the current study initially evaluates the seismic performance of PT-CRMWs compared to SRMWs. Next, a new controlled rocking system for masonry walls is proposed, namely Energy Dissipation-Controlled Rocking Masonry Walls (ED-CRMWs), which are designed to self-center through vertical gravity loads only, without the use of PT tendons. To control the rocking response, supplemental energy dissipation (ED) devices are included. This proposed system is evaluated experimentally in two phases. In Phase I of the experimental program, the focus is to ensure that the intended behavior of ED-CRMWs is achieved. This is followed by design guidance, validated through collapse risk analysis of a series of 20 ED-CRMW archetypes. Finally, Phase II of the experimental program evaluates a more resilient ED-CRMW is evaluated, which incorporates a readily replaceable externally mounted flexural arm ED device. Design guidance is also provided for ED-CRMWs incorporating such devices. / Thesis / Doctor of Philosophy (PhD)

Seismic Design Manual for Interlocking Compressed Earth Blocks Nicholas Edwards Kennedy This thesis presents a comprehensive seismic design manual to be used to design and construct simple Interlocking Compressed Earth Block (ICEB) structures in seismically active regions. ICEBs are earth blocks made primarily of soil and stabilized with cement. They have female and male stud mechanisms designed to interlock when stacked, eliminating the need for mortar. The blocks can accept reinforcement and grout after they are placed. While ICEB construction is similar to conventional masonry construction, current design code standards for masonry only partially capture the actual behavior of ICEB structures. This thesis seeks to supplement the existing masonry design procedures and tailor them for use with ICEBs. Additionally, this paper presents a preliminary design of ICEB shear walls for a disaster reconstruction project in the Philippines. While many structures in Southeast Asia and the Malay Archipelago are constructed from earthen blocks, very few are engineered. Of those that are, a lack of formal design guidance specific to ICEB construction leaves most engineers and designers with conventional concrete masonry design practices, some of which are not applicable for use with ICEBs.

No description available.

No description available.

<p>An experimental investigation was conducted to analyze the effectiveness of repairing and retrofitting the intersections of flanged concrete block shear walls using surface-bonded fiber-reinforced polymer (FRP) laminates for seismic load applications. A total of 18 specially designed flange-web intersecting wall assemblages were tested using 5 different schemes. Tests included wall intersections reinforced with unidirectional FRP with the fibers oriented perpendicular to loading direction (90°), parallel to loading direction (0°) and bi-directional (90°/0°), (90°/0°)2 and (45°/135°) to applied load direction. The behaviour of each wall specimen is discussed with respect to its failure mode, strength and deformation characteristics. Results showed that the laminates significantly increased the shear strength of concrete block shear walls junction. In addition, the fiber orientation influenced the failure mode, strength and stiffness. Moreover, depending on the fiber orientation, a significant enhancement to the post-peak load energy absorption capacity of the web-flange intersection can occur. The improved post-peak behaviour addressed the benefits of retrofitting concrete block wall intersections for seismic load applications. The FRP-retrofitted specimens were capable of reaching between 90% to 390% increase in strength compared to the umetrofitted specimen constructed with traditional steel joint reinforcement.</p> / Thesis / Master of Engineering (MEngr)

Masonry is an orthotropic material that exhibits distinct directional properties due to the existence of mortar joints acting as planes of weakness. Therefore, a constitutive model employed in the numerical analysis should be capable of describing the anisotropic behavior. The main objective of this research is to implement a macroscopic failure criterion which describes the failure conditions in structural masonry. For this purpose, a comprehensive framework is outlined for modelling of the mechanical behaviour of structural masonry. In this framework, the anisotropic material properties are described using the microstructure tensor approach (Pietruszczak and Mroz, 2001). Then, a mathematical formulation defining the conditions at failure is discussed. The formulation contains several material parameters as well as material functions that describe the anisotropic behaviour. The identification procedure for these functions is outlined and is verified using the experimental tests conducted by Page (1983). Later, an extensive numerical study, including a set of numerical simulations of biaxial compression-tension and biaxial compression tests for different bedding plane orientations, is conducted to evaluate the performance of the proposed macroscopic failure criterion. In the last part of the thesis, some 3D finite element simulations of a shaking table test are performed involving a reduced scale model of four storey masonry building subjected to seismic excitation. A linear dynamic analysis, in which the proposed macroscopic failure criterion is incorporated through the UMAT subroutine, is carried out to assess the plastic admissibility of the stress field. The results including the distribution of the value of the failure function are then compared with the crack pattern in the experimental test. / Thesis / Master of Applied Science (MASc)

This thesis investigates a constructive technique, within the materials and methods of conventional practice, which allows for a common building material such as concrete block to carry form and beauty. Furthermore, this project seeks to demonstrate the role human ingenuity, patience, attention, and perception can continue to play in architecture and construction. The project focuses on an experimental wall type consisting of regular eight inch concrete half-block masonry units, stack-bonded in elevation and subtly transformed in plan to reveal a gradual shift of the exposed faces of the units. A wall was constructed at the Building Research and Demonstration Facility to investigate one example of this wall type. / Master of Architecture