Effect of Nonlinear Modeling of Beam-Column Joint on Pushover Analysis
Amr.W.Sadek, Mohammed Moiz Khan
Page Numbers : 127-144
DOI : 10.36348/sjce.2022.v06i05.002
The present paper is concerned with the seismic risk assessment of buildings in the Kingdom of Saudi Arabia. A critical review of the existing literature is presented to identify the shortcomings of extant studies. None of the extant studies considered nonlinear action of the beam-column joint (BCJ) but rather they dealt with BCJ as a rigid element for simplicity and the only plastic hinging has been considered in beams and/or columns. Hence the main focus of this paper is to demonstrate the significant effects of the nonlinear action of BCJ in the pushover analysis and in turn the inadequacy of all previous studies which overlooked such effect. In this study, nonlinear static pushover analysis is performed on two-dimensional RC frames of existing buildings in Jeddah city, with and without using macro node elements and pushover curves are compared. The beam-column joint modelling approach adopted in this study is through macro node element which accounts for failure due to shear collapse of the joint, concrete crushing, flexural and/or shear plastic damage of the beams or columns connected and bond-slip failure. The results clearly indicate that the RC frame in which the beam-column joints were modeled using a macro node element, tends to have lesser base shear values and higher displacement capacity when compared to the RC frame modeled without using the macro node. Furthermore, the status of plastic hinges developed in building frames modeled without using macro node element was found to be within the Immediate occupancy (IO) performance level, but this hinge status drastically changed to Collapse prevention (CP) performance level when BCJ was modeled using macro node. Hence, the results highlight that the nonlinear action of beam-column joint has a significant effect on the nonlinear response of a structure.
Original Research Article
May 7, 2022
Analytical Studies on Retrofitted Anchorage System in Concrete using Strut and Tie Method
Padmanabham.K, Swapna B
Page Numbers : 115-126
DOI : 10.36348/sjce.2022.v06i05.001
Analytical studies were conducted on force transfer mechanism of retrofitted anchorage system in structural concrete by Strut-and-Tie modeling (STM). Post Installation of Headed anchorage (PIHA) as supplementary system introduced for implicit strengthening of anchorage system. The boundaries of STM are considered under direct tension pull-out test. Five different configurations of conventional reinforcement anchorage in concrete with straight bar, 90-degree bend, 180-degree hook, single head and double head bars are retrofitted by using PIHA technique. The mechanics of force transfer in anchorage system was analyzed by STM and validated the results by experimental program. The study parameters considered are (i) location of nodal zone, (ii) strut angle, (iii) size of strut (concrete) contributed during failure. The study variables are (i) configuration of anchorage system (ii) characteristic node formation and (iii) presence of supplementary reinforcement. The result shows good agreement with experimental findings against failure mode, stress pattern, and location of critical zone in conventional and retrofitted anchorage system. Use of this study may further extended to assess theoretical evaluation of failure mode, formation of critical section and stressed regions of discrete RC elements such as corbel projection, bracket connections and beam-column joints.
April 22, 2022
The Techniques of Cultural Heritage: Literature Review
Ahmed Kareem Jebur
Page Numbers : 108-114
DOI : 10.36348/sjce.2022.v06i04.006
Documentation of cultural heritage is basically a computerized or digital representation of objects contains the realistic portrayal of objects in 2.5 or 3D and other details. It is an unquestionable reality that the most vital thing for transmitting cultural heritage to posterity is a delicate documentation. Up to the present there have been numerous advancements in documentation of cultural heritage through technology development, and contemporary documentation techniques have progressed speedily. In time, current techniques have turned out to be desirable over conventional methods in engineering in the existent state and in assurance of disfigurements and preparation of measured drawing projects of historical edifices. Over the most recent ten years, direct 3D documentation techniques are very well known and that great advancement. Generally several main geomatics approaches are using for documentation , in first approach, image based such as close range photogrammetry, unmanned aerial vehicles, infrared (IR) images, second approach are non-image-based such as conventional measurements, terrestrial laser scanning, and In third approach, many researcher are using hybrid method that companied between different techniques. With ongoing improvements in PC and information technologies, this notable customary method has been change with digital close-range photogrammetry. This new technique offers us new open doors, for example, automatic orientation and procedure of the measurement, create of 3D vector information, advanced ortho-image and digital surface model. Laser scanning is another innovation that lately has turned out to be progressively well known for documentation which gives exceptionally thick 3D points on an object surface with high exactness. Also, the 3D model and ortho-photo can be effortlessly created utilizing produced 3D point clouds and recorded digital pictures. This paper gives an overview about the techniques related with documentation of cultural heritage and the uses of cultural heritage.
April 22, 2022
Application of 3D City Model and Method of Create of 3D Model- A Review Paper
Ahmed Kareem Jebur
Page Numbers : 95-107
DOI : 10.36348/sjce.2022.v06i04.005
In the last decades, 3D city models appear to have been predominantly used for visualisation; however, today they are being increasingly employed in a number of domains and for a large range of tasks beyond visualisation. In the past, the virtual 3D models are being built using primary materials, (e.g. wood), because of the flexibility and easy handling of this material, where the measurements are taken in traditional methods, so that the work is done in direct contact with the target . However, with the advancement and development of techniques, the virtual 3D models are produced by computer-aided design and by using of auxiliary software's such as, AutoCAD but with manual measurements. To overcome these difficulties, many techniques and remote sensing devices have been developed. These techniques are considered as the leaders in this respect and are commonly used in extracting 3D models nowadays such as photogrammetry and Light detection and ranging (Lidar). These techniques provide lots of information with high accuracy standards and reliability without direct contact with the real world (except for assessment and validation purposes). In this paper, we seek to understand and document the state of the art regarding the utilisation of 3D city models across multiple domains based on a comprehensive literature study including hundreds of research papers, technical reports and online resources.
Original Research Article
April 15, 2022
Static Pullout Tests on Retrofitted Anchorage System in Concrete Using Supplementary Reinforcement
Padmanabham K, Rambabu K
Page Numbers : 79-94
DOI : 10.36348/sjce.2022.v06i04.004
This paper presents experimental results of retrofitted anchorage system of structural concrete by using Post-Installation of Supplementary Anchorage (PISA) as a implicit strengthening measure and to improve the nonlinear performance of conventional anchorage system in hardened concrete. A total sixty specimens of M25 grade concrete (150x150x300mm) with two different size of rebar anchorage of 12mm, 16mm and five different configuration of conventional anchorage system was retrofitted by PISA technique is verified under direct tension pullout quasi static loads. The configuration of anchorage comprised by straight bar (A1), 90degree bend (A2), 180degree hook (A3), single head bar (A4) and double head bar (A5). The test parameters considered are bond strength, ductility, stiffness and bar-slip and test variables are configuration of anchorage, size of rebar and presence of supplementary steel. The obtained results validated by ANSYS modeling. This study concludes that a considerable improvement of nonlinear parameters such as ultimate load (3-8%), stiffness (4%-17%), ductility (16%-52%) and concrete contribution (6%-23%) by using PISA technique.
Original Research Article
April 11, 2022
Mixture Experiment Model for Predicting Static Modulus of Elasticity of Laterite-Quarry Dust Cement Block
Enang Egbe, Desmond Ewa
Page Numbers : 72-78
DOI : 10.36348/sjce.2022.v06i04.003
Laterite-quarry dust cement block are masonry unit produce by full replacement of natural sand with appropriate mix of laterite and quarry dust. Static modulus of elasticity is an important parameter in predicting the structural behavior in service under load action and determines the deformations and displacements distribution concrete and similar other structural members like blocks. In this work, a mathematical model is formulated using Mixture experiment for predicting the static modulus of elasticity of laterite-quarry dust block. The model is tested for lack of fit and found adequate.
Original Research Article
April 6, 2022
Deterioration and Failure Rates of Maintained Roads in Nigeria
Ezeagu CA, Ezema NM
Page Numbers : 64-71
DOI : 10.36348/sjce.2022.v06i04.002
This study evaluated failure rates of roads maintained by FERMA in Delta state and its effects. The three roads investigated are: Benin-Asaba dual carriage way (266km), Warri-Sapele-Benin dual carriage way and Asaba -Allah-Ebu Edo state border road(47km). Road condition survey was carried out on the three roads to ascertain the extent of deterioration. Sieve analysis, liquid limit, compaction and CBR tests were conducted on the material used for the maintenance works for quality control purpose. Liquid limit, optimum moisture content, unsoaked CBR values were 21%, 8.5% and 117% respectively. These were observed to be within the FMW highway manual guidelines. It was observed that beyond 12months, Benin-Asaba and Warri-Benin roads experienced 2% and 5% failure rates while Asaba-Illah recorded 30% failure rate within a 12month period. These failures were attributed to heavy traffic with heavy duty wheel. Challenges of road maintenance in the field and remedial measures for highway maintenance is also discussed. The authors recommend that FERMA should seek redress and go back to the establishing blue print for operations and funding and also refers to Federal Roads Authority bill (2015) for backups. These tools have been provided to equip the agency to carry out her mandate effectively keeping the road infrastructures in good condition.