Journal of Structural Engineering & Applied Mechanics - Golden Light Publishing ® | Trabzon

Journal of Structural Engineering & Applied Mechanics

ARTICLES

K. Senthil Iwansh Gupta S Rupali Loizos Pelecanos

An explosion on the elevated structures caused by terrorist activities or manmade events can induce significant deformations in the Civil Engineering structures. Therefore, it is necessary to review the response of the structural behavior such as reinforced concrete slab, reinforced concrete beams, and columns. On the basis of this objective, a detailed literature review is conducted to understand the scope for protecting such structures and the structural behavior under blast loading. Based on the detailed literature survey, the investigations about the behavior of conventional reinforced concrete columns and slab initiated in 2005 however, the behavior of reinforced concrete beam was focused since the year 2010. Also, the literature reveals that the investigations on structural elements using analytical techniques are limited in comparison to experiments and simulations. In addition to that, the response of the structural elements was predicted and the trend was calibrated and fitted logarithmically with the experimental results. The predicted spall diameter in the reinforced concrete slab is 0.95 m corresponding charge weight of 100 kg however the influence of spalling was found to be negligible after the 100 kg of charge weight. The predicted spall length in the reinforced concrete beam is 1.6 m corresponding charge weight of 100 kg and the effect may be negligible after 100 kg of charge weight. The predicted deflection in the reinforced concrete columns is 30 mm corresponding to a peak reflected impulse of 1000 MPa-ms, whereas the deflection was found to be negligible after the 1000 MPa-ms of peak reflected impulse.

https://doi.org/10.31462/jseam.2020.04216228


Mohd Firoj Sauhardra Ojha Prince Poddar Sanjeew Kumar Singh

The present paper focuses on the nonlinear static pushover analysis of a 3-span existing RC bridge located in Indian seismic Zone IV as per IS1893-2016 using the Finite Element Method (FEM). The 3D model of the RC bridge is simulated using the FEM technique and pushover analysis is performed to analyze the structure for modal mass participating ratio, performance level, spectral demand, and capacity of the structure. The bridge pier and longitudinal girder are modeled using the two noded beam element and bent cap and abutment of the bridge structure is modeled using the 8 noded brick element. The base of the column is assumed fixed condition. The pushover analysis is performed using Displacement Modification (FEMA 440) and Capacity Spectrum Method (ATC 40). The outcomes of results appear that the considered bridge has inadequate capacity to cope up with any of the desired performance levels because spectral demand is greater than the spectral capacity. The modal analysis of the 3D bridge exposes that it has many closely-spaced modes. The mass participating ratio for the higher modes is not very high. After performing pushover analysis of the exiting RC bridge structure it has been concluded that the existing bridge structure does not meet seismic criteria of spectral demand as per the ATC 40 and FEMA 440, therefore retrofitting is required for bridge component i.e. piers, abutment, and bent cap.

https://doi.org/10.31462/jseam.2020.04229243


Ahmed K. Ghoraba Salah El-Din E. El-Metwally Mohamed E. El-Zoughiby

The strut-and-tie method (STM) can serve as a tool for a safe design of concrete structures or members. It aids to trace the flow of forces, appropriately lay-out the reinforcement, and safely predict the structure capacity. On the other hand, the linear elastic finite element can be utilized as an alternative in the development of the strut-and-tie models besides the load path method. In addition, the nonlinear finite element analysis assists in the optimization of the design results obtained from the STM. Hence, the two methods work well as companions in structural design. In order to demonstrate such understanding, different examples which include a deep beam with large opening and recess, continuous deep beams with and without openings, and beam ledges, have been utilized. In the STM solutions, the ACI 318-14 failure criteria have been adopted. In the nonlinear finite element analysis, material nonlinearity has been accounted for. The obtained solutions from the two methods, along with the experimental data of the selected examples of this study, revealed the reliability of the STM in obtaining a safe solution. Besides, the nonlinear finite element proved to be an efficient tool in obtaining an economic design.

https://doi.org/10.31462/jseam.2020.04244275


Mohammed Salem Al-Ansari Muhammad Shekaib Afzal

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.

https://doi.org/10.31462/jseam.2020.04276288


Embiya Tilki Arif Velioğlu Baris Sayin

Masonry buildings are ordinarily complex construction systems and there is a lack of knowledge and information concerning the behavior of their seismic response. Due to the life safety of masonry buildings under seismic effects are very essential, numerical modeling and analysis of the buildings are an important issue. Because of the insufficient seismic resistance on structural members such as jack arch slabs and masonry walls, numerical studies have become necessary to determine the level of the structural strength of the structures. The tensile strength of load-bearing walls in the buildings is lower whereas, the compressive strength is higher. In this way, tensile cracks occur at structural members due to insufficient tensile resistance. Therefore, the tensile stress locations in the structure are critical. The study focuses on the assessment of historical masonry buildings from the point of seismic resistance. The entire process is performed using a case study from a historical masonry building. In this study conducted in this respect, the existing situation of a historical building using numerical analyses were presented with the cross-disciplinary study of civil engineering and architecture. The linear elastic analysis is selected as an analysis method. The seismic parameters are determined based on the Turkish Earthquake Code (TBEC 2018). Consequently, the study is performed to determine the seismic-resistant of historical buildings within the scope of numerical analyses.

https://doi.org/10.31462/jseam.2020.04289294