Analysis of Rectangular Reinforced Concrete Liquied Tanks by Using Yield Line Theory

In the analysis of rectangular reinforced liquid storage tanks, a method assuming linear-elastic behavior for material can be used, i.e., the strip method, the moment coefficient method, the finite element method, etc. In the analysis of these types of tanks, tank walls can be considered as slabs. In this study, tank walls were analyzed as slabs subjected to hydrostatic loading; in the analysis, the yield line theory is used because it is more suitable for the linear inelastic behavior of reinforced concrete slabs than the ones based on the linear elastic theory. An iterative algorithm based on yield line theory is presented for the design of isotropically reinforced recrangular concrete slabs supported along all four edges. A computer program is coded which predicts the location of yield lines for the slabs depending upon certain parameters. As a result of this prediction, the manual design of such slabs can be significantly simplified by the use of the coefficient obtained by using the program. It was shown that the analytical computation of the ultimate moment per unit length requires the solution of a highly nonlinear system of equations. This difficulty was overcome by utilizing an iterative technique within the computer program. It also gives the value of the ultimate moment per unit length of the yield line.

Experimental study on static response of prefabricated concrete bulb-tee bridge girder flange-to-flange connections

Prefabricated concrete Deck Bulb-Tee (DBT) bridge girder system requires precast girder flanges to be connected and formed bridge deck at site. In this study, a new bridge deck slab flange to flange connection system for precast DBT girders has been investigated. Two types of moment transferring connection and another two types of intermittent bolted connection were developed. A total of four full-scale bridge DBTgirders for the developed connection details were fabricated and then tested to collapse under simulated wheel load. This thesis reports on an experimental study on static behavior and ultimate load carrying capacity of bridge Deck Bulb-Tee girders jointed with proposed connection detail and technology. structural behavior, including stress and strain, crack formation and propagation, deflection, failure mode, and ultimate load capacity, has been identified. Experimental results are compared to those obtained using the Yield-Line Theory and the available Punching Shear Equations.

Experimental study on static response of prefabricated concrete bulb-tee bridge girder flange-to-flange connections

Prefabricated concrete Deck Bulb-Tee (DBT) bridge girder system requires precast girder flanges to be connected and formed bridge deck at site. In this study, a new bridge deck slab flange to flange connection system for precast DBT girders has been investigated. Two types of moment transferring connection and another two types of intermittent bolted connection were developed. A total of four full-scale bridge DBTgirders for the developed connection details were fabricated and then tested to collapse under simulated wheel load. This thesis reports on an experimental study on static behavior and ultimate load carrying capacity of bridge Deck Bulb-Tee girders jointed with proposed connection detail and technology. structural behavior, including stress and strain, crack formation and propagation, deflection, failure mode, and ultimate load capacity, has been identified. Experimental results are compared to those obtained using the Yield-Line Theory and the available Punching Shear Equations.

Propuesta de diseño estructural del pavimento rígido convencional y fibroreforzado de la Av. Sánchez Cerro en Piura usando la tecnología del reciclado mecánico

Debido al incremento tránsito, el poco o nulo mantenimiento de la vía, la falta de drenaje pluvial y los estragos ocasionados por el fenómeno de “El Niño Costero”, la infraestructura vial de la Av. Sánchez Cerro se ha deteriorado a tal punto de presentar fallas estructurales y nulos niveles de serviciabilidad que no permiten un tránsito adecuado de los vehículos y peatones que circulan por la zona, afectando el confort del ciudadano y el paisajismo de la ciudad. Ante ello, y debido a que la zona es altamente comercial, con muchas interferencias producidas por los servicios públicos, las tendencias de sostenibilidad a nivel global y los niveles existentes en el proyecto, se ha realizado optado por realizar una propuesta de rehabilitación del pavimento mediante una base reciclada de asfalto con colocación de una losa de pavimento rígido que permita cumplir con los objetivos del proyecto. El objetivo principal del estudio es realizar el diseño del reciclado mecánico, también conocido como RAP, y el diseño de la losa de concreto del pavimento rígido mediante las metodologías AASHTO 1993, PCA 1984 y la “Yield Line Theory” (basada en Technical Report N° 34 del Eurocódigo) utilizada para el diseño de losas reforzadas con fibras que permita verificar las condiciones de diseño, brindando soluciones tradicionales y alternativas que permitan mantener los niveles de la vía.

Development and Testing of a Test Level 4 Concrete Bridge Rail and Deck Overhang

A Manual for Assessing Safety Hardware (MASH)-compliant Test Level 4 (TL-4) concrete bridge rail was optimized to satisfy MASH TL-4 design loads, maximize vehicle stability, minimize installation costs, and mitigate the potential for deck damage by minimizing loads transfer to the deck. Additionally, the bridge rail was designed with a 39 in. installation height so that it would remain crashworthy after future roadway overlays up to 3 in. thick. The barrier had a front face with a 3-degree slope from vertical to promote vehicle stability during impacts while also providing some slope to allow for slipforming installations. Yield line theory was utilized to design both interior and end regions of the barrier. Further, minimum deck strengths were determined and a deck overhang design procedure was provided for users desiring to modify their existing deck details. Finally, MASH Test 4-12 was conducted on the new bridge rail to evaluate its safety performance criteria, damage to the barrier and a critical deck configuration, and its working width. In test 4CBR-1, the 22,198 lb single-unit truck impacted the concrete bridge rail at a speed of 57.6 mph and an angle of 16 degrees. The single-unit truck was successfully contained and redirected, and all safety performance criteria were within acceptable limits as defined in MASH. Therefore, test 4CBR-1 was determined to be acceptable according to MASH Test 4-12. Conclusions and recommendations for implementation are provided.

Assessing fragility of a reinforced concrete element to snow avalanches using a non-linear dynamic mass-spring model

This paper presents an assessment of the fragility of a reinforced concrete (RC) element subjected to avalanche loads, and more generally to dynamic pressure fields applied orthogonally to a wall, within a reliability framework. In order to obtain accurate numerical results with supportable computation times, a light and efficient Single-Degree-of-Freedom (SDOF) model describing the mechanical response of the RC element is proposed. The model represents its dynamic mechanical response up to failure. Material non-linearity is taken into account by a moment–curvature approach, which describes the overall bending response. The SDOF model is validated under quasi-static and dynamic loading conditions by comparing its results to alternative approaches based on finite element analysis and the yield line theory. Following this, the deterministic SDOF model is embedded within a reliability framework to evaluate the failure probability as a function of the maximal avalanche pressure reached during the loading. Several reliability methods are implemented and compared, suggesting that non-parametric methods provide significant results at a moderate level of computational burden. The sensitivity to material properties, such as tensile and compressive strengths, steel reinforcement ratio, and wall geometry is investigated. The effect of the avalanche loading rate is also underlined and discussed. Finally, the obtained fragility curves are compared with respect to the few proposals available in the snow avalanche engineering field. This approach is systematic and will prove useful in refining formal and practical risk assessments. It could be applied to other similar natural hazards, which induce dynamic pressure fields onto the element at risk (e.g., mudflows, floods) and where potential inertial effects are expected and for which fragility curves are also lacking.