Dissertations for Structural Engineering (Str.E)

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3- DIMENSIONAL CONCRETE PRINTING TECHNOLOGY
(The British University in Dubai (BUiD), 2022-01) ABDULJAWAD, NORAN AMER
The structural engineers are always in a challenge between the responsibility for the people life and the development in the structural engineering sector, the long spans or the height of the buildings also the modern design that needs flexibility required from the structural engineer to discover new ideas and seek for a new solution to break the limitation of the traditionally used manufacturing processes of the concrete, and move to a new page which is a smart structure-based new technology, such as 3D concrete printing, that will help the structural engineer and the construction sector to be more creative. Taking under consideration that every complex structure gives complex loads and dynamic nature, in addition to that it will increase time and cost which is very critical points in the construction stage. The present paper reviews all the properties, features, advantages, and disadvantages of 3D printing will be discussed with approval. This dissertation or thesis is surveying research, the type of the survey is a questionnaire, it was done online by using SurveyMonkey or Google Forms, and the design of the question was developed and selected carefully which includes a critical point about 3D printing, the questions were distributed between engineers with different engineering background, like civil engineers, structural engineers, MSc. in structural engineering, PhD. in structural engineering, and researchers. And it was targeting engineers in different locations and in different fields. This survey research includes questions that are divided into different sections. The types of the questions are closed-ended questions and that means quantitative research which provides numerical data that can be statistically analyzed to find correlation, trends, patterns. On the other hand, the result of the responses is static analysis, usually using computer programs like SPSS, Stata, or Excel. Knowing that survey results are organized and discussed in the conclusion.
ADAPTATION OF BIM WORKFLOW IN STRUCTURAL ENGINEERING PROJECTS & THE NEED TO ESTABLISH A NATIONAL BIM STANDARD
(The British University in Dubai (BUiD), 2020-02) Thomas Thampy, Tony
The Introduction of the concept of BIM into the construction industry, have made significant changes to the working standards and workflow pattern. This thesis examines the said changes in comparison to the traditional working methods in all phases of project starting from pre-concept to demolition with respect to the structural engineering discipline. Case studies are done to check the typical workflow in a BIM environment for structural design. Thus analysing the skills required and deliverables that are to be produced in BIM working environment for optimum workflow. The BIM implementation strategies and the rate of BIM adaptation in 5 selected countries including UAE are analysed. The relation between national BIM standards and the rate of BIM implementation in the respective countries are also evaluated. The current BIM awareness in the UAE is also analysed by a market survey conducted among industry experts in the UAE, focusing on the obstacles for the implementation of a national BIM strategy. The adaptation of the BIM into the structural engineering workflow has shown many improvements in comparison to the traditional workflow such as software interoperability, ease of production of schedules and drawings, 3D representation of reinforcement and other technical data, etc. National mandates and standards in relation to BIM have shown to increase the rate of BIM adaption in respective countries and also achieve a sense of regularity in the construction industry and authority standards. From the market survey conducted, the professionals have expressed the need for similar BIM standardisation in the UAE and also the current obstacles for the same.
Advanced Composites as Reinforcement for Concrete
(The British University in Dubai (BUiD), 2021-05) Alsamaraie, Ibrahim
Recently, the demand for building concrete structures reinforced with steel rebars is gradually increasing worldwide. The serviceability of these reinforced concrete structures is affected by multiple factors, one of which is exposure to extreme weather conditions. Deterioration of steel rebars is one of the most common issues caused by the harsh environment's weather. The degradation of concrete structure is mainly driven by steel corrosion. Fiber-reinforced polymer (FRP) rebar is considered an innovative and durable choice rather than conventional steel reinforcement for concrete structures. GFRP bars were classified as an excellent corrosion resistance compared to conventional steel due to their mechanical performance. Several researchers have performed numerous studies out to explore the flexural response of GFRP bars. As a result, it is crucial to establish effective FE models that can be employed to comprehend the essential structural behavior of such systems and the performance under applied loads. The flexural behavior of structural reinforced concrete beam components was presented in this study utilizing 3D ANSYS 21 FEA simulation. This study compares an FE model with experimental findings from previous works and the ACI 440.1 model. Graphical representations were discussed, including the deflection of the mid-span stress-strain relationship. The specimens are rectangular beams that are simply supported and have spans and clear spans of 2.4 m and 2.1 m. A four-point pseudo-static experiment was performed on the samples. The findings indicate that fibre-reinforced composites can be evaluated using ANSYS software with an adjusted model. The difference between FEA model results, experimental tests, and ACI 440.1 theoretical formulas predicting failure loads is within a 10% margin of error. The results have demonstrated the ACI 440.1 code conservatism compared to the remainder of the results obtained from environmental findings or FE simulations.
ANALYSIS OF COMPOSITE ACTION OF PRECAST HOLLOW CORE SLABS AND CAST IN PLACE MESH REINFORCED CONCRETE TOPPING
(The British University in Dubai (BUiD), 2019-09) Omer, Sajjad
Considering composite action of hollow core slab with cast in place mesh reinforced concrete topping helps to provide longer hollow core slabs and reduces the overall weight of the structure. Research has shown that composite action normally can be attained through studs or other connecting elements from the bottom element but for hollow core slabs the roughness of the top surface is enough to attain the composite action. This study aims to analyze the composite action of hollow core slabs made of ELEMATIC sections with thicknesses 150mm and 265mm with cast in place mesh reinforced topping. The thickness of topping was considered as 65mm for 150mm thick hollow core slab and 70mm for 265mm thick hollow core slabs. A load test setup was made for both 150mm thick hollow core slab and 265mm thick hollow core slab which mirrored the actual site condition. The connecting reinforcements were provided as per normal practice and the supports were considered as simply supported after which the topping was setup with the wire mesh and the concrete poured. Readings from the three gauges below the hollow core slabs were recorded at 0% loading, 25% loading, 50% loading, 75% loading, 100% loading, 100% sustained loading and 0% released load condition after 24 hours. For 150mm thick hollow core slabs, 0.29mm was the deflection for 100% sustained loading and for 265mm thick hollow core slabs, 3.36mm was the deflection for 100% sustained loading. These two values are way less than the actual estimated values. The results indicate that composite actions are valid for uncracked hollow core slab sections considered in the tests. Further investigations can confirm the composite action for other hollow core slab sections and also for section which are cracked
Analyzing the structural cost, performance, and flexibility in the terminal design of Mumbai Airport
(The British University in Dubai, 2018-09) ZAMA, SYED MUDASSIR US
The recent growth in the aviation industry has led to the highest necessity for the development in designing the airports. Statistics are available for a few airports, but there is no comprehensive base of information on how airport terminal buildings operate or the conditions their user experience. The major aim of this research is to design a framework for analyzing the performance, cost and flexibility in terminal design of airports; to do so the main studies has been done exploring factors affecting the management and functionality of airport terminals considering the different parameters and the effectiveness of the terminal and the key challenges in designing functional aspects of an efficient airport terminal. The contribution of this research work will help approach to develop an efficient framework to overcome the problems occurring in airport terminals. The research paradigm will be positivism, carried out scientifically in order to analyze the performance and flexibility of the airport terminal. SPSS software has been used for the descriptive and regression data analysis for interpretation; the analysis presents an elaborate picture of the findings; other statistic tools are also used. The conclusions are based on the analysis of data presented, suggestions are made for, and that can be analyzed, in coherence with the research objectives further if any. Hence, posit certain areas of research that can be further extended and broadened by other researchers in near future.
ASSESMENT OF STRUCTURAL ELEMENTS DETERIORATED IN SEMI ARID ENVIRONMENTAL CONDITIONS
(The British University in Dubai (BUiD), 2022-10) KHAN, MOHAMMED FARAAZ
Deterioration of concrete is a prominent occurrence that happens due to several factors surrounding a structure making the place inhabitable with a risk to life and property. These factors and the impact of deterioration depend upon the surrounding environmental conditions of the structure and vary for different geographical locations. The deterioration of concrete in a structure if assessed properly can be stopped from propagating further and economical solutions can be proposed to rehabilitate the structure. This dissertation aims to find the most prominent type of deterioration using different testing methods in semi-arid environmental conditions like the United Arab Emirates. It further aims to assess the data retrieved by statistical analysis to find its effect on the structural elements, such as the slabs, column and beams. The statistical assessment of the data provides significant information about the deterioration and its effect on the structural elements. Furthermore, the dissertation progresses by investigating the effect of deterioration on the design forces by modelling a structure with the acquired data from the site and comparing it with a non-deteriorated structural model of the same. Analysing the design forces helps to assess the effect of deterioration on various structural elements. Moreover, the dissertation also portrays the effect of deterioration on the most effected structural element which are the columns and asses the loss in capacity due to deterioration. The assessment and the interpretation using statistical analysis and modelling of the structure along with design helps to understand the effect of deterioration on structural elements in semi-arid environmental conditions.
The behavior of Tapered High Strength Concrete Filled Steel Tube (CFST) Column connected to Encased Steel Reinforced Concrete Composite (SRC) Column
(The British University in Dubai (BUiD), 2020-06) Abdelhamid Azzazy, Yasser
The use of Convectional Concrete Column is often limited in high-rise Buildings due to the constraint from the architects on increasing size of the columns, so the composite columns provide appropriate solution to satisfy the architect and the Client with smaller column size. Nowadays, Composite Columns have been widely developed in the construction of the high-rise buildings, long span structures, and bridges. Composite columns have two main types, encased composite columns (SRC) and concrete filled steel tube columns (CFST). This research is focusing on the behavior of a tapered concrete filled steel tube column (CFST) connected to encased composite column (SRC). The purpose of having two different sections along the column height is to enhance the flexure resistance of the column at the top edge by introducing CFST element, while the lower part is modeled as SRC element and it is mainly subjected to axial compression with significant reduction in bending moments compared to the top part of the column. The behavior of the tapered CFST column connected to SRC column has been studied using two main different parameters. The first parameter is the type of loading, such as pure axial compression, axial compression and uni-axial bending, and axial compression and bi-axial bending. The second parameter is the concrete strength, with different concrete strengths ranging from C40MPa to C70MPa. Both parameters have been carefully considered in the analysis of the composite column. The steel section used in the research design model has a yield strength of 355MPa. The steel reinforcement used in the model has a yield strength of 500MPa. The column has been modeled using 3D-Fiber (Solid) Finite Element Method. The cross sectional of the columns has been divided into tiny fiber (solid) elements. The advantage of using a fiber (solid) element is easy to assign the tiny element as concrete or steel, even stiffeners plates have been modeled by adopting the fiber element methodology. The maximum size of the fiber (solid) element is (10mm x 10mm) which warrant more accurate results in terms of stress and strain. The vertical rebar was ignored from the 3D Fiber Model. The stresses and strains extracted from the 3D-FE models have been compared to the simplified formulas adopted by EUROCODE-4 and American Standards AISC / ANCI . The research illustrates the load path and stress / strain distribution through different structural elements connected to each other under deferent type of loading. The results demonstrate that the 3D-FEM displays some differences in the composite section capacity under different type of loading compared to the simplified formula adopted by Eurocode and AISC/ANCI. The stress and strain distribution demonstrate a smooth transition between CFST element and SRC element with local stress concertation on the concrete and steel at the interface between CFST element and SRC element. The concentration in the stresses is not considered in the simplified formula by the standards codes, so it should be carefully considered in the section capacity.
Comparative Study of the Structural Behaviour of Cast Acrylic & Laminated Glass Under the Impact of Dynamic Loading in Aquatic Applications
(The British University in Dubai (BUiD), 2023-12) ABUZOUR, MOHAMMED A. E.; Dr Gul Ahmed Jokhio
Laminated glass (LG) and cast acrylic (CA) materials have differences in their structural behaviors regarding the impact of dynamic loading in aquatic applications. The difference can be due to these materials' consistency and mechanical properties. This study aimed to distinguish the differences in structural behaviors of cast acrylic and laminated glass in aquatic applications under the impact of dynamic loading and what industry guidelines and standards can be developed to ensure their safe and effective use in this setting. The study starts in Phase I by selecting the strip method for both LG and CA to observe the deflection magnitudes of hydrostatical pressure of a 40mm thickness tank wall that has a depth of 6m, and then a shell element model for both materials was built using CSI SAP software to establish accurate statistical modeling of the tank with same wall thickness and exerted hydrostatic pressure depth. The results in Phase I exhibited that CA sheets had 10% to 15% more deflection than it was in LG, and experienced negative bending moments of about 90 kN.m near the base edges, and around 40 kN.m as maximum positive bending moments. Whereas LG’s straining actions recorded a magnitude close to 100 kN.m as positive bending moments and almost 180 kN.m as negative bending moments near the edges at the same parameters of the study. In Phase II of the study, the materials were submitted to dynamic loads analysis to examine their structural boundaries. The model was established using LS Dyna software to mimic an accidental collision incident of amphibians and/or mammal creatures to the LG and CA tank walls. Masses, velocities, hydrostatic pressure, and wall thicknesses were all included in Phase II of the study to assess the impact of each variable on the built model. The study achieved accurate simulations since there were four different parameters in each analysis running cycle allowing sophisticated investigations of both materials by pushing their structural behavior under the impact loads of collisions to their extreme boundaries, especially when gradual incremental changes in the magnitude of each parameter are applied. The model was adjusted to compare the actual deflection and applied stress criteria with the aforementioned four variable parameters. The obtained results exposed the superiority of CA sheets in most of the collision cases in contrast with LG. CA sheets had the least deflection and stress values in regard to wall thickness, however, they showed a gradually increasing deflection against higher velocities in contrast with LG which revealed rather constant deflections versus the same set of velocity increments. LG sheets expressed a dramatic increase in the applied stress against the increment of the colliding mass, however, they could remain more conservative against recorded deflection magnitudes under the same increment set of moving mass. Finally, CA sheets recorded slightly lower deflection values than it was in LG under the increasing effect of hydrostatic pressure (collision depth) and eventually showed almost a constant behavior of stress but significantly lower than those recorded in LG sheets.
Comparison and Critique review of Durability Provisions and Design Requirements of Various International Design Codes and Standards.
(The British University in Dubai (BUiD), 2022-09) AL-HADDAD, DIALA BASEM
Codes and standards establish a standardized language and set of rules for building design, construction, and operation. Such codes and standards have long been the primary mechanism used by governments to establish agreed-upon norms within a territory. These codes are under continual development and update to respond to the outcomes of proven search and the ongoing evolvement of technology and construction processes. Building codes are primarily concerned with establishing a framework for structural capacity and serviceability; nevertheless, many do not effectively consider durability design. In the absence of clear standard guidelines for design engineers, insufficient design and failures or an expensive over-design to provide for the worst-case scenario may occur. Failures in durability design endanger public safety and put a strain on the government's budget. The ACI 318 code is the most widely used code for the design of new concrete structures. Adapting this code will result in a cost-effective concrete structure that is sufficient to withstand the applied loads, however, the provisions about durability are not well understood or thoroughly documented. The goal of this study is to compare the development of the ACI 318 durability design approach to international codes and to suggest improvements to the provisions in light of this comparison. The proposed upgrade may be a beneficial start for the ACI code committee to begin updating the following ACI code generation. The study revealed that the provisions of the ACI 318 code are not comprehensive and well documented, the requirements are prescriptive and dispersed throughout the code chapters, the terminology lacks crucial terms related to durability, and that complex structures and a highly aggressive environment are not included. On the other hand, in the European code and British standards, provisions are more detailed, harmonized, and comprehensive. Additionally, the investigation uncovered inconsistencies in the way ACI publications provided durability criteria for corrosion caused by chlorides, resistance to freezing and thawing, and chemical sulphate attack. Inadequate durability design and implementation can lead to structural failures; as a result, design codes need to be improved to enable code practitioners a coherent, understandable foundation for creating designs that can withstand the environment for their specified service lives.
Comparison between Nonlinear Analysis and ACI Simplified Effective Stiffness Analysis Methods for Reinforced Concrete Frames Under Lateral Load
(The British University in Dubai (BUiD), 2023-11) ELMUTASHY, HAJER; DR GUL AHMED
When reinforced concrete frames subjected to lateral load manifesting in inelastic damage in the form of cracks that diminish the structural element's stiffness. Evaluating this damage often employs non-linear analysis, yet simplified methods prescribed by international codes and numerous studies estimate the effective stiffness of these elements are used for elastic linear analysis. The accurate estimation of effective stiffness is crucial as it profoundly impacts the overall structural performance. This research endeavors to compare the non-linear performance of the structure with the linear performance using the assumptions proposed by ACI-318-19, permitting the use of 0.7EIg and 0.35EIg as effective stiffness values for columns and beams, respectively. To achieve this, 66 one-bay one-story frames are modelled and subjected to non-linear static analysis using ETABS software. The model parameters encompass compressive strength, reinforcement ratios, column height and axial load. The analysis presents load-deflection characteristics for the entire frame which used to calculate the effective stiffness. Results subjected to statistical analysis which indicate that increasing compressive strength augments structural stiffness, whereas heightened axial load and frame height notably diminish stiffness. Conversely, employing the non-linear analysis method result in higher effective stiffness than simplified method by mean value of 1.36, 1.44 and 1.57 for frames with compressive strength 40,80 and 120mpa respectively. Keywords: effective stiffness, static nonlinear analysis, simplified stiffness method
Comparison between the American code ASCE7-16 and the Australian code AS1170.4 against the seismic design effects
(The British University in Dubai, 2018-11) AL-OBAIDI, ALI
Engineering is a professional art of applying science to the efficient conversion of natural resources for the benefit of man. Engineering, therefore, requires above all creative imagination to the innovative, useful application for natural phenomenon.” (International Journal of Engineering Research & Technology (IJERT), Vol. 3 Issue 3, March – 2014). This work implemented to compare two codes, American and Australian by designing a sixty -floors building using reinforced concrete structure from the economic point of view. Two critical structural codes adopted, ASCE-7 16 and AS1170. These codes compared in term of strength design necessities of structure elements and the shear design included as well. During this study, calibration and elaboration of the models adopted along with the criteria consecration revealed. Though the main principles are the same and the seismic zone will moderate, the details were different and made the comparison accurately, the analysis implemented via ETABs software from CSI Company established in the USA. This work will show the development of the Australian code especially for the earthquake loading using the AS1170.4, 2007. The Australian engineers established new response spectrum design contains a better illustration of the acceleration, displacement and velocity for the type of site soil (soft and rock). The used procedure to establish the spectrum could use in another country which has a low/ moderate seismicity. The AS1170.4 used a tiered approach for the earthquake load starting from simple force to complicated displacement method. One of the significant advantages of this method especially on the low seismic zone is given the engineers to design against the vertical and wind loads then perform the displacement checking for the earthquake impact. In parallel, the ASCE-7 16 deliver the all the possible design requirements for general structures along with the dead, live, snow, flood, rain, soil, wind load, and atmospheric ice with the proper combinations which is fit for the building code. The standard is a revision of ASCE-7 10 which is a revision of ASCE-7 5 respectively and it's providing a full update and re-arranged of the wind load. Also, it has a new ultimate wind load maps along with the reduced load factors and it has an update on the risk targeted seismic maps. This standard is a comprehensive and important version as a part of the building codes which are used in the United States.
Comparison between theoretical and practical compression capacities of deep / long piles
(The British University in Dubai, 2017-11) OMAR, MOHAMED NABIL
The rate of build of high-rise buildings has accelerated rapidly, especially in the Arabian Gulf, over the last few decades, due to rapid urbanization and significant improvements in the field of the high-rise construction and technology. Many challenges were faced by the engineers in the design and construction of such buildings. One of the major challenges was the foundation systems, which are required to ensure the stability of the buildings. The common type of foundation system which is used in case of high- rise buildings is piles foundation system. In the most standards and codes of practice such as British Standard and ASTM, the piles specifications and recommendations are stated for short piles which has a maximum depth range between 18.0 to 20.0 m. Theoretical equations for pile design, charts and different soil factors and parameters are based on old studies of short piles behavior. In this research, a comparison was conducted between the theoretical pile compression capacity which is calculated from the theoretical equations and the practical pile compression capacity which is derived from the results of pile’s static load test. The study covered three different cases of bored piles constructed in U.A.E especially in Dubai. The piles used in this research have a depth ranging from 30.0 to 65.0 m. This type of piles is classified in this research as long or deep piles. A finite element model of each pile was modeled by using PLAXIS 2D software, to compare the practical and theoretical piles capacities. It was found that the theoretical compression pile capacity is 60 to 70% of the practical pile capacity with the same specifications (pile diameter and pile depth). As a conclusion of the results, the theoretical equations which are used to calculate the pile compression capacity can be improved to give results very near from the practical condition.
Comparison of the Provisions of ACI318-19 Code and Eurocode on the Structural Design and Cost Analysis, of a High-rise Concrete Building Subjected to Seismic & Wind Forces
(The British University in Dubai (BUiD), 2021-05) Oussadou, Samy Elhadi
This work aims to compare two codes; ACI 318-19 and Eurocode in terms of lateral effect on high-rise building, focusing on the seismic and wind provisions, and since these two forces effect the structural elements geometry, thus the cost comparison was included, by comparing the amount of reinforcement used. Since both of the codes have different standards and factors, therefor it is expected that there will be some differences in the structural design. This research contain design and analyses of a high-rise building consisting of 50 storeys reinforced concrete structure and comparison of several provisions. This research study investigates the difference between seismic and wind results between the two codes and if there might be any differences in the structural elements reinforcement amount, which will affect the cost of the building.
A Correlation between Theoretical and Actual Column Shortening and Lateral Sway in a Vertically Asymmetric High-Rise Concrete Building
(The British University in Dubai (BUiD), 2016-11) Habrah, Alaa
The consideration of columns shortening in high-rise buildings becomes more complex and needs more attention when the building is vertically asymmetric. The inherent complexity is attributed to the dramatically unequally loaded vertical members due to mass shifting after the separation floor (the floor after which the plan is significantly reduced), which consequently leads to building rotation toward the higher side causing more lateral and vertical displacements. The gravity loads induced sway and settlement of a 360m height vertically asymmetric building in Dubai are investigated in this research. The columns and core walls elastic and time-dependent shortenings are predicted using the ACI 209R-92 model considering all the compensation measures taken, the construction method adopted, and the site conditions revealed during the construction of the tower. Sophisticated calculations including all the influencing factors of this model were performed using an Excel sheet to provide a simple interface for calculating the elastic and time-dependent columns shortening. The building was also analyzed by finite element method software, Etabs where the columns shortening and settlement were predicted using CEB-FIB 90 model for time-dependent effects which was built-in the software. The results of the two models were evaluated by comparing them to site survey readings conducted each five floors during the tower construction. It was found that both methods overestimated settlements in all floors compared to actual ones. Whilst the average overestimation of the developed Excel sheet based on the ACI 209R-92 model was 630%, Etabs analysis based on the CEB-FIB 90 model had more accurate results with average overestimation of 258%. The lateral sway induce by gravity load was predicted by the same Etabs model using two different analyses, linear and nonlinear staged construction analysis. The sway results of the two models where compared to each other to get a comprehensive overview of this behavior. Further investigation was done on a modified building model where the vertical asymmetry was removed and the building was re-analyzed by the two analyses again. The advantages and disadvantages of each analysis were provided. It was found that the linear analysis significantly overestimated the lateral sway for the original model, whereas the two analysis had close results for the modified model. The analyses results clearly evidenced that nonlinear staged construction analysis is essential to capture the real behavior of vertically asymmetric buildings.
Corrosion Monitoring Technologies for Reinforced Concrete Structures: A Review
(The British University in Dubai (BUiD), 2023-06) SHEHADEH, KHADIJA; Dr Gul Ahmed
Reinforced concrete (RC) structures are susceptible to many problems which would lead ultimately to the degradation of RC structures or a total loss in the worst-case scenario. Corrosion represents one of the main degradation sources. Due to the vital impact size of corrosion of RC structures in the form of high maintenance demand and an increase in the total life cycle cost, corrosion monitoring, early detection, and timely remediation is considered a necessity and a crucial proactive measure to control corrosion and limit its impact. In this work, the main classifications of corrosion monitoring systems were explored, highlighting their features, advantages, disadvantages, and future recommended works. To achieve that a state-of-the-art literature review was employed. Six main categories were identified from the literature: visual inspection, electrochemical methods, elastic wave methods, electromagnetic methods, fiber optic sensing methods, and mechanical methods. The subcategories of each of these were reviewed highlighting its concepts, pros, cons, and outlook and future works. Irrespective of the adopted processes for corrosion monitoring, it was concluded that none of these methods represent an optimum solution by itself, where employing a combination of multiple systems is one way of optimizing its results. New technology, algorithms, data processing, and AI are new approaches to improving corrosion monitoring processes. However, it needs further development and research.
Critical Review of Reinforced Concrete Design Codes and Their Relevance to the United Arab Emirates
(The British University in Dubai (BUiD), 2018-11) GOWRISHANKAR, PRATHIBHA
The United Arab Emirates, is a home to structural engineers from different nations who hold expertise in their regional building concrete design codes. Since the 1980’s and 1990’s The British Standard (BS 8110) and the American Standards (ACI 318) have been of significance and widely used within the Municipalities in UAE. To maintain a uniformity and consistency in design and analysis of structures, it is required to critically review design codes to closely examine the similarities and differences among code provisions. This could help structural engineers to switch between codes. Hence, an attempt is made to carry out a general and parametric comparison of some international design codes followed by a three-tier critical review of ACI 318-14 and BS 8110-97 considering the fact that these codes are widely used within UAE. The three-tier comparison involves examining the results of literature review, theoretical investigation and practical design of frame elements of a G+40 story building using ETABS software. The results were compared in terms of dead and live loads and their combination, flexural and shear capacity of beams, columns and slabs, deflection and minimum and maximum amounts of longitudinal and transverse reinforcement, to arrive at a more economical solution without compromising strength and stability requirements. The results of the three-tier critical review showed that designs conforming to British Standards are preferred over the ACI Standards owing to their adaptability to the construction industry and environment in UAE which contributes the best possible solution.
Critical Review of Steel Column Base Plate Design Codes and Their Relevance to United Arab Emirates
(The British University in Dubai, 2019-05) SREENIVASAN, SREEJU
Structural engineers are often posed with a question for an economical design of a structural building which would decide the overall economic and the time concern in a construction. If the design is at optimum by choosing a suitable code the involvement of the materials would be less which will help to decrease the pollution caused in the environment as well. In short where structural steel works are being used with other structural materials the importance of various connection plays to be indispensable. One of which the steel column base plate connection that would perform adequately for the specified demand. This is the most critical element in the entire structure which would carry the load of the entire building through the columns to transfer to the base plate and then to the ground and ensuring the stability of the structure. Hence this dissertation intends to bring about a requirement of workability such as the easy and efficient construction, working the connection with high loads and deformation with sufficient capacity ensuring least cost, maintenance and with long durability with an economical design code. In the United Arab Emirates where the country is home to all the high rise structures will need this aspect as the cost involved is at high steak. The three codes which are thus reviewed in this are the Eurocode, American and the British standard codes emphasizing more on latter two codes (British and American). The involvement of the computer analysis supporting the work will provide much understanding to choose which code is more suitable for a desired project for the municipalities and consultancies in U.A.E.
Effect of location of thickened concrete slabs and type of material on the seismic behavior of structure buildings
(The British University in Dubai (BUiD), 2021-11) EL-FEQY, KHALED HAMED ABD ELHADY
The design against lateral force (wind load and seismic load) is mandatory for high rise buildings. There are many factors that should be considered while estimating the seismic force that shall be applied to a building as well as certain checks to ensure building safety against that seismic force. Many structural engineers attempt to keep the seismic drift within the allowable value given by code of practice. The common problem is the seismic drift exceed the allowable values. Different solution is used to overcome this issue such as increasing in shear wall size, use larger size of beams, use thickened slab, use bracing, use advanced mass damper etc.. Practically, the idea of use thickened slab appears to author while design building with transfer slab. The more thickened transfer slab, the less seismic drift is obtained. This idea may not studied before from this point of view. Thus, this research focuses on the estimation of seismic behavior of concrete structures by performing many structure models with different heights at moderate seismic zones. The seismic force in this research is based on UBC97 code of practice. All the structural models have been analyzed and compared in similar circumstances. The research also attempts to find a practical solution which doesn’t need advanced technology by increasing the slab thickness in certain floors to reduce the seismic drift. The increase in slab thickness causes a complete change in all structural analysis results of a building (the total displacement and the total base shear). This research covers the results of increasing the slab thicknesses to obtain a good comparison between all models. Results show that the thickened slabs is good solution for seismic drift. The thickened slab should be located at certain floors to get the optimum reduction in seismic drift as well as the seismic drift shape of the structure. On the other hand, another approach using Ultra High Performance Concrete (UHPC) is used in certain floors without changing the slab thicknesses to observe the effect of using UHPC on the seismic behavior of structural building. Results of second approach show using of UHPC has a minor effect on the seismic behavior compared to results using the thickened slabs.
Estimating Bridge Deterioration Age Using Artificial Neural Networks
(The British University in Dubai, 2017-09) AL HUSSEIN, ASEEL
Deterioration of reinforced concrete bridges is major issue in structural engineering due to the difficulty of estimating or predicting the service life of the bridge. Two types of models were developed to estimate the service life, the deterministic and probabilistic models. Nevertheless, the reliability of these models is questioned since they do not account for the many factors involved. Therefore, for this research artificial neural network is used to estimate the deterioration age for RC bridges based on deterioration data. Historical records of bridges located in London is used to train and test ANN. Feedforward neural network is designed to be able to estimate the deterioration age. ANN inputs are bridge type, member type, exposure, and defects while the target is the defects age. Since there are no standard neural network deterioration models, Design of experiment is conducted to select and monitor the most important parameters that would affect ANN performance. Learning algorithm, Number of hidden layers, number of hidden neurons and Transfer function are the four parameters selected for factorial design. Each factor has low and high-level options making 16 different combinations of neural networks. ANN analysis is run on MATLAB and Mean Square Error (MSE), regression and error histogram results are used to evaluate the performance of ANN. The results were mediocre reflecting the type of data provided in neural network training. ANN models could successfully train more than half of the data to achieve the target, However, the rest of the data were not able to achieve the desired output. Furthermore, Analysis of Variance (ANOVA) is used on MSE to determine which parameter influenced the outcome. Hidden neurons are significant factor were MSE of 10 neurons is smaller than MSE of 20 neurons, indicating a better performance for ten neurons models. Then, the deterioration scenarios are compared with ANN output age. Footbridge bridge and compression members had the longest average for service life.
Evaluation of Compressive Strength for Recycled Aggregate Concrete Reinforced with Polypropylene Fibers
(The British University in Dubai (BUiD), 2021-05) Omar, Turk
The compressive strength of recycled aggregate concrete reinforced with polypropylene fibers was investigated. The possibility of using polypropylene fibers (PPF) in the recycled aggregate concrete (RCA) was extensively studied. Moreover, the mixes experimented were using different RCA replacement ratios and different PPF content. The results present the compressive strength behavior of Recycled Aggregate Concrete (RAC) with and without addition of Polypropylene (PP) fibers. The normal coarse aggregate was replaced by recycle aggregate in the percentage of 0, 25, and 50%. The polypropylene fibers (PP) were used in the recycle aggregate concrete by 0.2% and 0.35% by volume. The values of compressive strength of the natural aggregates concrete (NAC) were set as a control. 27 concrete cubes (150x150x150mm) for each RAC and NAC were casted making a total of 54 concrete cubes. Three cubes for each designed mix were also cured for 7 days and 28 days. The test results revealed that the incorporation of PP fibers did not considerably change the compressive strength and the density of concrete, but the compressive strength of RAC was satisfactory at the early ages until the later ages where NAC was higher than RAC. Therefore, use of recycled aggregate concrete showed tolerable performance with respect to compressive strength and will have a better employment at fast setting concrete where early strength is required. Furthermore, more studies are necessary to determine the effect on durability and enhancement to the workability.

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