Structural Safety Review of a Building Damaged by Explosion in Mexico City

2016 ◽  
Vol 713 ◽  
pp. 111-114
Author(s):  
Jorge A. Avila ◽  
Jorge Arturo Avila-Haro
Keyword(s):  
Reinforced Concrete ◽  
Mexico City ◽  
Longitudinal Direction ◽  
Present Condition ◽  
Structural Safety ◽  
Seismic Zone ◽  
Joint Work ◽  
Lateral Capacity ◽  
Capacity Curves ◽  
Reinforced Concrete Slabs

The structural assessment of a building damaged by the effects of an explosion located in Mexico City is presented. The structure consists in 12 complete levels, a thirteenth partially completed level for elevators, and a basement. The building is mainly conformed of steel frames with box columns, I-beams and trusses; peripherally reinforced concrete slabs attached to girders through shear connectors; its reinforced concrete box foundation (basement slab, grade beams and floor slab) is supported on control piles at a depth of 5.9 m. The building did not present any damage in the 1985 Mexico City earthquake; the original structural design is from the 1960’s (RCDF-66) [1], for a reduced seismic coefficient cs= 0.06. A review of the present condition of the structure against the requirements of the current RCDF-04 (transition seismic zone: Ts~1.0 s and cs=0.32; Q=2) was performed in this work [2]. Based on the three-dimensional structural behavior, spectral modal dynamic analyses were performed, including the joint work of the super-structure and the foundation. The structure does not present any lack of lateral stiffness and/or resistance problems, even after the explosion. According to the non-linear static (Push-over) analyses (with and without over-strenghts effects), the lateral capacity curves prove that the building has a slightly higher lateral capacity in the longitudinal direction and, to a lesser extent, in the short direction, than the one required in the current regulation. No corrective structural actions were needed, except for the rehabilitation of the structural elements affected by the explosion.

scholarly journals Modeling of joint work of steel beam constructions with reinforced concrete ribbed floor slabs

2021 ◽  
pp. 44-57
Author(s):  
Yevhen Dmytrenko
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Precast Concrete ◽  
Concrete Slabs ◽  
Effective Width ◽  
Joint Work ◽  
Load Bearing ◽  
Reinforced Concrete Slabs ◽  
Industrial Buildings ◽  
Floor Slabs

Traditional methods of calculation of beam constructions of floors and coverings of industrial buildings assume their consideration when calculating separately from the frame structures, in particular, reinforced concrete slabs, without taking into account their joint work, which leads to a significant margin of safety. Today in Ukraine there is a significant number of industrial buildings and structures that need strengthening and reconstruction. In this regard, of particular importance are studies of the actual load-bearing capacity of the frames of single-storey and multi-storey industrial buildings, and both in the reconstruction and in new construction, the results of which will significantly reduce costs and more rationally design structures. At the same time, one of the most relevant areas is the study of the joint work of metal load-bearing structures with prefabricated reinforced concrete structures of rigid disks of coatings and floors in their calculation.           Moreover, in the national building codes, as well as in the educational and methodological literature, the calculation methods of taking into account the joint work of such constructions are not fully covered. The purpose of this work is to estimate the reduction of mass of the metal beam structure in its calculation in bending, taking into account the joint work with the rigid disk of the floor consist of precast concrete. As part of the study, the calculation of the floor beam according to the traditional calculation scheme - without taking into account the joint work with the floor slab, the calculation of its cross-section taking into account the joint work with floor slabs and experimental numerical study of the floor by the finite element method. Modeling of the floor fragment was performed in the software packages "SCAD Office" and "LIRA CAD 2019". Numerical research is aimed at verifying the feasibility of using the calculation methodology of DBN B.2.6-98-2009 to determine the effective width of the shelf when calculating the T-sections for prefabricated reinforced concrete slabs, which are included in the joint work with the floor beams. A comparative analysis of the obtained cross-section of the beam with the beam which was previously calculated by the traditional method of calculation  in stresses in the most dangerous cross section and the total mass of the beams. According to the results of the analysis, the correctness of the application of the above normative method for determining the effective width of the shelf of T-bending reinforced concrete elements was confirmed.

scholarly journals Does the design according to the seismic zone affect the environment and the manufacturing cost of a 5-storey R/C building with a conventional plan?

2021 ◽  
Vol 899 (1) ◽  
pp. 012032
Author(s):  
Theodoros Chrysanidis ◽  
Athina Gkigki ◽  
Grigorios Papageorgiou ◽  
Nikolaos Alamanis
Keyword(s):  
Reinforced Concrete ◽  
Cross Sections ◽  
Manufacturing Cost ◽  
Seismic Zone ◽  
Structural Members ◽  
Reinforced Concrete Building ◽  
Reinforced Concrete Slabs ◽  
Concrete Building ◽  
The Cost ◽  
Bearing Structure

Abstract The main scope of the present research is the analysis, dimensioning and estimation of the cost of a five-storey reinforced concrete building, which is similarly constructed in three different seismic hazard zones (ZI, ZII, ZIII). The ground plan of the building is a conventional floor plan with solid reinforced concrete slabs. The cross-sections of the structural members remain stable, except for the columns whose cross-sections are reduced in height. The aim of the present study is to analyze how the cost of manufacturing the load-bearing structure of a reinforced concrete building is affected by the seismic risk of the area, if that influence is significant and in what extent. Moreover, along with the construction cost, the possible influence to the environment is studied, too.

scholarly journals Structural analysis and design of irregular shaped reinforced concrete slabs using a simplified design method

2020 ◽  
Vol 3 (4) ◽  
pp. 276-288
Author(s):  
Mohammed Salem Al-Ansari ◽  
Muhammad Shekaib Afzal
Keyword(s):  
Reinforced Concrete ◽  
Numerical Solutions ◽  
Design Method ◽  
Structural Safety ◽  
Concrete Slabs ◽  
Analysis And Design ◽  
Finite Element Software ◽  
Reinforced Concrete Slabs ◽  
Simplified Method ◽  
Simplified Design Method

This paper presents a simplified method to analyze and design the irregular reinforced concrete slabs based on structural safety and economy. The triangular, trapezoidal, and curved slab sections are selected in this study to be analyzed and designed using a simplified design method approach (SDM) as these sections are the most common type of irregular slab sections used in the construction industry. Flexural design formulas for triangular and curved slabs are derived based on the theoretical principles of plate and yield line theories and ACI building code of design constraints. Numerical examples are presented in this study to illustrate the method capability of designing the most commonly used irregular slabs sections. The complete design of four triangular slabs (TS-1 to TS-4) and four curved slabs (CS-1 to CS-4) is provided in this study. Besides, the required equivalent (triangular and rectangular) shaped sections are provided to deal with irregular trapezoidal slab section. The selected irregular slab sections (triangular and curved slab sections) are also analyzed and designed using the computer software (SAFE) and the results obtained are compared with the numerical solutions. The percentage difference of the simplified method with the finite element software (SAFE) ranges from 4% to 12%. The results obtained for all the selected irregular shaped slab sections indicates that the SDM is a good and quick approach to design irregular (triangular and curved) slab sections.

scholarly journals COMPOSITE REINFORCED CONCRETE BRIDGE GIRDERS FOR POST-CONFLICT RECONSTRUCTION OF THE DESTROYED TRANSPORT INFRASTRUCTURE

2021 ◽  
pp. 28-37
Author(s):  
M. HERNICH ◽  
S. KLUTCHNIK ◽  
D. SPIVAK
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Transport Infrastructure ◽  
Joint Work ◽  
Advantages And Disadvantages ◽  
Post Conflict ◽  
Reinforced Concrete Slabs ◽  
The Impact ◽  
Concrete Girder

Purpose. The purpose of this work is to analyze the existing composite reinforced concrete girder structures of bridges, determine their advantages and disadvantages, study of stress changes in the elements of the girder structure and its deflections caused by the coupling of metal beams and reinforced concrete roadway, the possibility of using these structures in post-conflict reconstruction. Methodology. Examination of the data covered in the literature. Studying the experience of design and construction of reinforced concrete girder structures of bridges in our country and abroad. Construction of the calculation model, its loading, change of thickness of a reinforced concrete plate, the analysis of results. Findings. The result of this work is collected data on the advantages and disadvantages of reinforced concrete girder structures of bridges under the railway, the impact on stress in the elements of the girder structure and on its vertical deflections by the joint work of metal beams and concrete slab, analysis of the possibility of using such girders for fast resumption of train traffic. Originality. It lies in that for the rapid and high-quality restoration of destroyed transport infrastructure, including railways, it is proposed to use metal beams of long-term storage (mobilization reserve), which are made on standard projects in the middle of last century, combined with reinforced concrete slab included in joint work, thereby obtaining composite reinforced concrete girder structures. This will allow rational use of the available reserve of materials, high recovery rates and reliable recovery of train traffic. Practical value. Based on the obtained data, it is possible to conclude that the method of combining the long-term stored metal beams and reinforced concrete slabs of the carriageway increases the load-bearing capacity of the obtained girder structures, so the use of these structures can ensure the effective restoration of war-torn railway structures in a short time.

Methodology of studying the mechanical properties of composite materials (reinforced concrete)

2018 ◽  
Vol 84 (12) ◽  
pp. 61-67
Author(s):  
V. A. Eryshev
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Experimental Studies ◽  
Analytical Relationship ◽  
Hardened Concrete ◽  
Deformation Model ◽  
Joint Work ◽  
Concrete Shrinkage ◽  
Axial Tension ◽  
Tension And Compression

The mechanical properties of a complex composite material formed by steel and hardened concrete, are studied. A technique of operative quality control of new credible concrete and reinforcement, both in laboratory and field conditions is developed for determination of the strength and strain characteristics of materials, as well as cohesion forces determining their joint operation under load. The design of the mobile unit is presented. The unit provides a possibility of changing the direction of loading and testing the reinforced element of the given shape both for tension and compression. Moreover, the nomenclature of testing equipment and the number of molds for manufacturing concrete samples substantially decrease. Using the values of forcing resulting in concrete cracking when the joint work of concrete and reinforcement is disrupted the values of the inherent stresses and strains attributed to the concrete shrinkage are determined. An analytical relationship between the forces and deformations of the reinforced concrete sample with central reinforcement is derived for axial tension and compression, with allowance for strains and stresses in the reinforcement and concrete resulted from concrete shrinkage. The results of experimental studies are presented, including tension diagrams and diagrams of developing axial deformations with an increase in the load under the central loading of the reinforced elements. A methodology of accounting for stresses and deformations resulted from concrete shrinkage is developed. The applicability of the derived analytical relationships between stresses and deformations on the material diagrams to calculations of the reinforced concrete structures in the framework of the deformation model is estimated.

scholarly journals Effect of the Geometrical Constraints to the Wenner Four-Point Electrical Resistivity Test of Reinforced Concrete Slabs

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4622
Author(s):  
Kevin Paolo V. Robles ◽  
Jurng-Jae Yee ◽  
Seong-Hoon Kee
Keyword(s):  
Experimental Investigation ◽  
Electrical Resistivity ◽  
Reinforced Concrete ◽  
Concrete Slab ◽  
Plain Concrete ◽  
Electrode Spacing ◽  
Concrete Slabs ◽  
Reinforced Concrete Slabs ◽  
Spacing Ratio ◽  
Geometrical Constraints

The main objectives of this study are to evaluate the effect of geometrical constraints of plain concrete and reinforced concrete slabs on the Wenner four-point concrete electrical resistivity (ER) test through numerical and experimental investigation and to propose measurement recommendations for laboratory and field specimens. First, a series of numerical simulations was performed using a 3D finite element model to investigate the effects of geometrical constraints (the dimension of concrete slabs, the electrode spacing and configuration, and the distance of the electrode to the edges of concrete slabs) on ER measurements of concrete. Next, a reinforced concrete slab specimen (1500 mm (width) by 1500 mm (length) by 300 mm (thickness)) was used for experimental investigation and validation of the numerical simulation results. Based on the analytical and experimental results, it is concluded that measured ER values of regularly shaped concrete elements are strongly dependent on the distance-to-spacing ratio of ER probes (i.e., distance of the electrode in ER probes to the edges and/or the bottom of the concrete slabs normalized by the electrode spacing). For the plain concrete, it is inferred that the thickness of the concrete member should be at least three times the electrode spacing. In addition, the distance should be more than twice the electrode spacing to make the edge effect almost negligible. It is observed that the findings from the plain concrete are also valid for the reinforced concrete. However, for the reinforced concrete, the ER values are also affected by the presence of reinforcing steel and saturation of concrete, which could cause disruptions in ER measurements

Critical shear crack theory-based punching shear model for FRP-reinforced concrete slabs

2020 ◽  
pp. 136943322097814
Author(s):  
Xing-lang Fan ◽  
Sheng-jie Gu ◽  
Xi Wu ◽  
Jia-fei Jiang
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Shear Crack ◽  
Concrete Strength ◽  
Weight Ratio ◽  
Punching Shear ◽  
Concrete Slabs ◽  
Crack Theory ◽  
Reinforced Concrete Slabs ◽  
Rc Slabs

Owing to their high strength-to-weight ratio, superior corrosion resistance, and convenience in manufacture, fiber-reinforced polymer (FRP) bars can be used as a good alternative to steel bars to solve the durability issue in reinforced concrete (RC) structures, especially for seawater sea-sand concrete. In this paper, a theoretical model for predicting the punching shear strength of FRP-RC slabs is developed. In this model, the punching shear strength is determined by the intersection of capacity and demanding curve of FRP-RC slabs. The capacity curve is employed based on critical shear crack theory, while the demand curve is derived with the help of a simplified tri-linear moment-curvature relationship. After the validity of the proposed model is verified with experimental data collected from the literature, the effects of concrete strength, loading area, FRP reinforcement ratio, and effective depth of concrete slabs are evaluated quantitatively.

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