Theses supervised by Prof. Dr. Zeki Hasgür
19 theses · Altınbaş University
Yatay yüklere maruz olan çelik elyaf takviyeli betonarme duvarların yapısal davranışlarının ANSYS programı ile incelenmesi
Reinforced concrete walls are considered one of the most important applications in the field of buildings construction, especially tall buildings, because of their ability to withstand high stresses caused by loads. Therefore, the purpos of this research is to investigate the capabilities of shear walls reinforced with fiber steel to discover the amount of deformations that occur in the presence of horizontal forces. The work in the research was divided into two phases. The first phase is to test the samples of concrete cubes to obtain the necessary data for the mechanical specifications of the samples. The second is the work of simulations using the ANSYS program. Walls of different heights were tested and subjected to different values of lateral forces to simulate normal use in civil engineering works. The results showed that the maximum horizontal load for walls reinforced with fiber steel exceeds the horizontal load values for ordinary concrete walls, safe in terms of bending capacity or shear strength. FE analytical tests performed for the two studied cases indicate that the load deformation response and final load behavior in concrete shear walls are in agreement. The study also showed that the optimal cohesion is when steel fibers are added to the concrete of the shear wall with a high loading effect. The midline distortion of the numerical model was compared with the experimental data, which showed the same distortion behavior
Comparison of the effect of the position of shear walls in high-rise buildings on the horizontal stiffness of the building under the effect of horizontal earthquake loads
The earthquake has turned into a menace to our lives and the infrastructure of countries. Several earthquakes have struck the world in recent years, causing extensive damage such as building destruction and material and human losses in various parts of the world. To reduce the number of casualties, we must make building construction structures more rigid so that they can withstand the force of an earthquake while it is occurring, as well as increase the thickness of the shear walls, which play an important role in resisting lateral forces because they are stiff and strong. In this PAPER, I will address the effect of shear wall position in buildings of 5 stories and 15 stories under seismic load in (zone c) as per code provision TSC 2018, which includes changes in base shear, storey displacement, and storey drift, as well as other data related to shear wall effect. The study was carried out to determine the effectiveness of the shear wall in a building by changing the position of the shear walls as a result of the analysis completed using ETABS software.
Investigation of the effect of taking together shear and bending deformations of reinforced concrete shear walls in high-rise buildings under horizontal loads
Natural hazards are considered primary concerns in engineering. Earthquakes' effects are crucial to take into consideration when designing. They cause ground motion under the structures. The buildings therefore vibrate under inertia loads causing excessive stresses on the structural components which result in collapses. High-rise buildings are subjected to a more critical acceleration because of its increased height. Normally, shear walls are provided to tolerate lateral loads and maintain a stiff-rigid system. In this thesis, using response spectrum dynamic analysis method and Erzincan's 1992 N – S spectra, 2 cases of a 20-storey high- rise office building are studied and analyzed to investigate the effect of taking both bending and shear deformations in reinforced concrete shear walls under horizontal loads. There will be 2 types of shear walls under study: frame shear wall and core wall. The analytical results show that there is a slight reduction percentage in a set of parameters such as periods, maximum core moments, frame shear wall moments, and deflections.
Beton mukavemetinin kirişlerin yapısal performansı üzerindeki etkisinin değerlendirilmesi ve simülasyonu
The tensile strength of concrete as it in less ability to resist the tension stress formed by the external loading, the increasing of the concrete strength can enhance the capability of the tension zone in the cross section to handle the effect of the tension stress for more upper limits without reaching the cracking section state. The study aimed to build effective analysis of the scope of increasing the strength of concrete to rise the internal strength of the tension region. The study took the effect of the width of beam, the height of the beam, and the reinforcement area into account then evaluated each parameter percent of impact. The height of the section showed the bigger impact percent so that the study derived equations based of the effect of the height F(h) on the strength index which referred to the compressive strength of concrete divided by the square of the load for concentrated load case and by the square of the distributed loading for uniform loading case. The study then modified the equation for various width of beam values to get F(h), b then for various span length values to get F(h),b,h. the study used the two cases loading (concentrated load and uniform loading to examine the possibility of the derived equation for each case to show the close to actual state of cracked load and cracked uniform loading based on various heights and widths of the RC beam. The strength index for the two cases was examined after the processing the equation by building many charts including curve fitting techniques. The strength of concrete was examined fro range 30 to 50 MPa, the study explained the results by the derived formulas and by the working stress steps with low differences indicating the applicability of the new equations to improve the decision making for increasing the strength of the concrete under specific conditions of the RC dimensions. The study built 3d images simulation using ANSYS program. The stress on the cross section for Fc in the mentioned range was investigated according the safety factor values
Betonarme yapının, temeline yataklık eden eğimli zemin katmanlarının sonlu elemanlarla modellenerek çözümü
This study deals with the use of finite element analysis to study the response of an RC building that has inclined supporting leads in the foundations. These buildings have a lot of weaknesses that need to be found and then properly developed. Therefore, shear walls had been built for these buildings to reduce seismic forces. A verification study was performed to analyze the RC building using SAP2000 software, which was collected from previous literature. Several RC buildings were studied to evaluate the seismic performance of these buildings under the influence of change in the degree of inclination of the foundations (0°, 10°, 20° & 40°), the number of storeys (8, 12, 16 & 20 storey), the span length (4, 5 & 6) m, and the storey height (3, 3.5 & 4) m. The buildings were analyzed using the SAP2000 software using the time history and response spectrum analysis methods under the influence of the EL-Centro N-S 1940 earthquake acceleration record. The results were shown that the values of base shear, time period and roof displacements decreased by 23%, 33% and 55% respectively, when the degree of foundation inclination of the building increased from 0° to 20°, due to the difference in stiffness and geometry of the buildings having inclined foundation. While these values increased by 68%, 53.28% and 137.6% respectively, when the No. of stories increased by 50%. The increase of base shear due to increase the height of building, also the increase lateral displacements of the buildings. The increases in time period due to decrease the stiffness of RC buildings and it has more displacements at tip of the buildings. Using the response spectrum method, when the storeys number were 12 the values of displacements decreased by 56% when the degree of the foundation inclination increased from 0° to 40°, at the 12th storey level. In the case presence of shear walls, the values of base shear, time period and roof displacements increased by 50% and decrease by (48% and 60%) respectively, under the influence of the increase in the degree of inclination of the foundations.
Assessment of hybrid RC building having various bearing isolators
Approaches to isolating the base have become a crucial element in enhancing quality stability during a seismic earthquake. In the present day, base detachment is routinely utilized as an essential arrangement technique for structures and frameworks in seismically active zones. The important objective of earthquake engineers is to design and build a structure in such a way that damage to the structure and its structural components during an earthquake is minimized. This thesis aims towards the dynamic analysis of a multi-story building with various parameters. For the sake of study and verification, a model of a ten-story RCC building with a symmetrical floor plan is considered. The study was conducted using SAP 2000's time-history-based software. Several structural compositions (RC, steel, and hybrid structures), different isolators (lead rubber bearings (LRB), friction pendulum bearing, fixed, and hinged), number of bays (3, 4, and 5), and number of floors were explored in 168 models in this thesis (7, 10, 13, and 19). The response of the structure, such as time period, base shear, and story displacements, is examined and compared. The study demonstrated the effectiveness of isolation approaches for earthquake resistance. Due to the building's lowest drift story, the friction pendulum support has been favored above other types of support systems. However, although the findings demonstrated a high time period when utilizing lead rubber bearings (LRB), which demonstrates the model's capacity to endure Earthquake load, a fixed support system is not favored for seismic loads due to the larger story drifts compared to other bearing support types. The steel structure was found to be superior in terms of base shear. Combining steel and concrete for the creation of new hybrid structural systems looks to be a potential strategy for earthquake-resistant design.
Birlikte almanın etkisinin araştırılması takviyeli kesme ve bükme deformasyonları yüksek binalarda beton kesme duvarları yatay yükler altında
The need for buildings is growing in developing nations as their populations and cities expand. Natural disasters like earthquakes can have a negative impact on human civilization. To quote a popular saying, "earthquakes don't kill people; buildings do." This is due to the fact that the majority of earthquake fatalities result from the collapse of buildings. Buildings designed to withstand seismic activity, such as by employing core walls and/or shear walls, should have some lateral stiffness to prevent excessive swaying even during moderate earthquakes. In this thesis, the effect of taking both bending and shear deformations in reinforced concrete shear walls under earthquake load is studied and analysed in four different cases of a 20-story high-rise office building in both directions (X and Y) using the response spectrum dynamic analysis method and Erzincan's 1992 N -S spectra. Shear walls with frames and those with core walls will be examined. According to the calculations, as the shear forces, maximum displacement, and maximum moment for the shear wall and core increased, the stiffness of the structure decreased. Data shows that shear deformations, in comparison to bending deformations (without shear deformations), increase time periods.
Yatay rüzgar yüklerinin etkisi altında yüksek binalardaki perde duvarlarının konumunun bina yatay rijtliğine etkisinin karşılaştırılması
In developing countries, the demand for high-rise buildings is increasing due to urbanization and population growth. Also, there is more demand for "tall buildings" as there is less land for buildings. It is imperative for these buildings to withstand lateral loads and prevent excessive displacement and swaying of the building. Buildings must be strong enough to withstand vertical forces and rigid enough to withstand lateral forces. In making a building resistant to lateral loads, the primary consideration is to ensure the location, dimensions, and symmetry of the shear wall, and to construct shear walls around the building and around a central core. The aim of this study is to analyse the behaviour of a 20-storey hotel building under the effect of equivalent earthquake force according to the Turkish Building Earthquake Code of 2018, by using the Muto method in the analysis of the shear-frame interaction with Group Loads, by using the "Force Method", and to analyses the results in Eurocode at 30 m/sec. To compare the effects of wind force obtained using (EN 1991-1-4) The results found that the forces that have the greatest impact on the building are the seismic effects due to the seismic activity in the area where the building will be built.
Perde yapısı ve çerçevelerden oluşan yüksek beton binaların deprem etkisi altında grup yükleme ve etablar ile hesaplanması
Structural Engineers are primarily responsible for determining the characteristics of a structure while exposed to lateral force, and high-rise buildings must be sufficiently stiff to withstand horizontal forces generated by storms and earthquakes. It is possible to prevent substantial displacement and, as a result, damage caused by displacement by utilizing shear walls in buildings. The previous latest damaging earthquake in Turkey was the Van 2011 earthquake, which damaged several structures, the majority of which were constructed with moment-resisting frames. This research investigates the use of shear walls over moment resisting frames at various points in a G+50 multi-story building, as well as the earthquake exposed character of the structure using Response Spectrum Analysis. The Multi storied building was analyzed for various structural irregularity induced by the ground motion. The numerical results indicate that adding shear-wall at all the corners of the structure can be the most effective against seismic effect.
Hesaplanması ve karşılaştırılması ile yüksek yapıların dönemlerikuvvet yöntemi – grup yükleme ve etab'lar
In view of the huge possibility for the deployment of current reliability systems in the structures, it is imperative that the efficiency of each method be evaluated, analyzed, and demonstrated in order to persuade the firms that design buildings to adopt them. Attributed to the reason that time history impulses recorded at a specific location are the result of a random process that is nearly impossible to replicate, a substantial amount of effort has been invested in recent years into the processing of actual records in order to make them "representative" of future input histories to construction that is already in place as well as construction that is planned to be built in areas that are prone to earthquakes. In this investigation a G+20 story structure with various structural systems including moment frame, bracing system and shear wall was analyzed to find the actual structural response under the dynamic analysis. Further the brace frame and the shear wall model were analyzed according to the site dependent spectra and for this the EI-Centro earthquake data was taken for the analysis. From the analytical result both the model consists of shear-wall and bracing system depicted significant improvement in the stability and the time period of the structure in the linear dynamic analysis. While comparing the nonlinear time-history analysis against the EI-Centro earthquake data both the shear wall and brace frame model was comparable and depicted enough structural stability, however, the shear-wall depicted the over-all vi performance improvement when comparing the data against the earthquake time acceleration.
Üç farklı maliyet karşılaştırması yüksek binalardaki zeminler
The aim of the research is to compare three different types of floor systems (Conventional, Flat, Waffle) from an economic perspective for tall buildings. For the purpose of this study, three models of a typical 25-story RC building structure with different spans length will be utilized. These models have all been checked and analysed under the influence of gravity loads and lateral loads. Three different models were compared. According to the comparison of materials costs for each model with different floor systems, it has been found that conventional floor systems are more cost-effective in tall buildings with intermediate span lengths, waffle floors are more economical for buildings with longer spans, and flat floor are the most expensive in both cases.
Yapı yapısı uygulamasında geri dönüştürülmüş beton ve cam elyaf ile geri dönüştürülmüş betonun mukavemetinin incelenmesi
The durability of recycled concrete reinforced with glass fiber over time is essential to its use as a construction material. While it's true that recycled materials have a number of immediate advantages, you need also think about how they'll hold up in the long run. Due to its environmental benefits, the use of recycled materials in building construction has gained appeal in recent years. Using recycled products helps conserve energy, lessen trash, and lessen the environmental impact. Research done so far suggests that recycled concrete's compressive strength can be improved by incorporating glass fibers into the mix. Recycled concrete with 1.5% glass fiber had 11.4% greater compressive strength than recycled concrete without glass fiber. Fibers of Glass Glass fibers can be used to mechanically improve recycled concrete, but the right proportion needs to be identified in advance. The production costs go up and the strength goes up as more glass fiber is used. The optimal glass fiber composition for strength and durability is established by weighing the costs and benefits.
Kendiliğinden yerleşen betonarmanın dış davranışıçelik lif içeren kirişler ve nanocam tozu
This study examined the impact of nano-glass powder and two SFRC distributions on self compact concrete beams. it is found that adding 5% nano-glass powder has higher compressive strength than coarser materials due to its fineness. also, 7.5% replacement fracture strengths reached 3.51 MPa. This method reduces waste and maximizes concrete recycling, according to the results. in addition, the bending test includes tensile and compressive forces, flexural strength is usually higher than tensile strength. These two forces boost fiber flexural strength. At 26 kN, or 40% of the final failure load, the flexural zone fractured initially. Concrete lasts longer when steel fiber is added between 0 and 1%. Natural and manmade fibers reinforce concrete. A slight variation in load-deflection behavior, which was linear up to the yield point where it was measured. The load-deflection curve entered the plastic zone well after the reinforcement yielded, remaining practically horizontal until the ultimate/failure load.
Güçlendirilmiş malzemelerin yapısal davranışıçelik içeren beton kirişler lifler ve nanocam tozu
Structural concrete performance has a different characteristic from those of regular concrete at the different levels of structural elements and their effects on capacity. This is done by evaluating the structural acts that steel fibers and nano glass particles in molding the behavior of concrete material and affect the shear resistance. This thesis investigates the impact on concrete of varying the concrete percentage, water-to-cement ratio, nano-glass powder content, and SFRC impacts based on 331 kg and 486 kg of cement. The results show that increasing the nano glass powder decreased the cement beam reliability properties while SFRC percentages were shown to increase beam reliability. The splitting results were reduced by the nano glass powder, and the flexural results improved as the SFRC was raised.
Boy farkının etkisi sismikte sismik düzenlemeleriuzun betonarme tasarımı binalar
This thesis as mentioned in its title, will discuss the different between the high-rise buildings (tall buildings) and the normal height ones. The domain of the comparing will be held among several aspects that affect the design and occupancy of the constructions such as: the response of these two types to the lateral loads, the drafts, the lateral settlements, the amount of loads occurs, the needed reinforced concrete and so on. As a sample, 5 floors building (will be assumed for the normal height prototype while a 20 floors building will be taken as a high rise building example. To have a fair comparison, collect correct data and get true information, the same working plane will be chosen for both cases of study. The huge development of the technologies has contributed to reduce the efforts and help the designers to solve the problems in no times comparing with the past decades. So, the simulation of the samples will be performed on a computer software which is ETABS 18.0.1. I hope it will be a useful and valuable thesis.
Yüksek binalarda üç tip betonarme zemin için bina maliyeti karşılaştırması
After the increase in the population, the world resort to high-rise buildings and a lot of researchers and engineers developed this type of building, and because the cost of high-rise buildings is expensive, must search for the best type of flooring to get the best quality of building and the best price, in this thesis a High-rise Building designed with structures software (ETABS-SAFE), with three types of floors and calculating the quantities of concrete and rebar to compare between them and to find which is more economical.
An efficient concrete compressive strength prediction method based recurrent neural network and particle swarm optimization algorithm
One of the greatest dangerous parameters in concrete project is compressive strength. As the compressive strength of concrete is properly slow, cost and time can be reduced. Concrete strength is comparatively hardy to influences on the situation. The manufacture of concrete compressive strength is importantly predisposed by severe climate environments and growths in moisture rates. In this study, efficient method presented combined RNN with PSO to predicate the Concrete Compressive Strength. The proposed method compared with two classical methods neural network and naïve bayes classifier. The proposed method presented best results than classical techniques when several metric parameters are compared such as mean error, mean squared error, mean percentage error, and root mean squared error.
Comparison of two statically solution methods of special factory frame
The manual methods for structural analysis entail a lot of complexity and repetitive computations. From the standpoint of structure design, the bending moment is a critical metric. To compute the bending moment, various approaches were used in this study, which including Moment Distribution, moment redistribution, Flexibility matrix method and the ETABS software. Moment Distribution, moment redistribution where used in the analysis of beams whereas Flexibility matrix method and ETABS where used in the analysis on the frames. The results show that the bending moment produced using both approaches is almost identical. Because the number of checks that were carried in the Flexibility matrix method is not significantly high, the findings produced using this method are highly precise. KEYWORDS: Flexibility Matrix Method, ETABS, Moment Distribution
Filistin'deki devlet hastanelerinin sismik değerlendirilmesi
Due to their diverse complexities, hospitals have specific regulatory construction requirements to mitigate physical and functional vulnerabilities that can arise during seismic events. Special considerations in seismic risk mitigation are needed to create a safe environment for patients and staff during disasters as well as play a crucial role in saving lives and reducing the suffering after disasters. The importance of safe and reliable hospital structures makes it abundantly clear that the engineers' primary duty to the public is ensuring that hospitals can withstand disasters related to seismic events. Our main concern is seismic parameters that take into account site conditions. In this research, we present a topographic influence and the effect of its modifications on seismic behavior, as well as differences in the design of public-hospital facilities in Palestine based on the time period of the basic mode of construction according to codes of practice .It has been shown that seismic behavior varies from one region to another and from one structure to another according to many variables including the type of soil to be built on, and the seismic behavior variables across regions and structures , different terrains directly affect seismic design elements, system considerations, and structural analysis methodologies. This study chose different types of public hospitals in Palestine and collected various statistical information about the nature of their practice in the previous years. The data were used to build three distinct hospital models based on three different topographies: Qalqilya, Ramallah, and Jericho. To complete the analysis and provide the required suggestions, the time frame for the basic model of the structure should be established as a minimum to reach the safety of public hospitals in multiple building systems of the same structure. The local code-based assessment was carried out using a variety of tools, including the ETABS program, which employed the capacity spectrum method. Pushover analysis is a form of non-linear static analysis that is used in the construction industry. Results have been reached that put the structural designer on the right track for safe structural design within the engineering specifications and conditions