Strengthening historical buildings and evaluating their performances make great contributions to both the history of the country and the tourism of the country. In this study, performance analysis and evaluations of the historical cinema hall bal-cony, which was built in 1933 by a French company and served to Zonguldak prov-ince for a long time, are presented in detail. This cinema hall was frequently used by local people between 1933 and 1999 and hosted many Yeşilçam movies. Firstly, ex-aminations were performed in the historical cinema hall and the areas (columns, beams and floors) that were damaged in time were identified. According to the ob-tained information, it was determined that there were significant damages in the car-rier system of the building and there were visible cracks and damages in the columns of the cinema hall. It was also observed that explosions occurred in one of the main carrier columns of the balcony. After the core samples taken from the balcony were tested in the laboratory, the currentstatus of the carrier elements and reinforce-ments were determined with the help of an x-ray rebar scanner. After all these pro-cesses, the structure was modeled as three dimensional (3D) using a special com-puter program and performance evaluations were performed regarding the current state of the structure. As a result of the performance evaluation, it was determined that the balcony of the historical cinema hall could not survive anymore and would collapse over time. It was concluded that there were great damages especially on the balcony columns and a reinforcement should be made on a total of 6 columns. Strengthening was made to 4 different main columns and a performance analysis was performed again in strengthened structure. After strengthening, it was understood that the columns of the balcony of the cinema hall could survive for a long time.
|
The usage of computer software in civil engineering has expanded in last decades. Many general-purpose and special-purpose commercial programs perform a very important function, especially at the design stage. In this study, a computer program is introduced for the analysis and design of the axial symmetric cylindrical wall con-sidering the dome effects. Analysis processes are carried out according to Flexibility theory with long wall assumption and during the reinforced concrete (RC) design of the wall, ACI 318-Building code requirements for structural concrete are considered. In numerical investigation, the effects of the dome properties (thickness and height) on the analysis and design of the wall are investigated by performing a totally 72 case analyzes. These cases include different support condition at bottom of the wall, wall heights, dome thicknesses and heights. According to analysis results, it is concluded that effects of dome thickness and heights on the wall on the wall are very limited.
|
Tuned mass dampers (TMDs) are used to damp vibration of mechanical systems. TMDs are also used on structures to reduce the effects of strong forces such as winds and earthquakes. For the efficiency of TMD, optimization of TMD parameters is needed. Several classical formulations were proposed, but metaheuristic methods are generally used to find the best result. In addition, the metaheuristic based opti-mum results are used in machine learning of artificial intelligence-based models like artificial neural networks (ANN). These ANN models are also used in development of tuning equation via curve fitting. The classical and ANN-based formulations were found according to frequency domain responses. In the present study, the classical and ANN-based formulations were evaluated by comparing on time-history re-sponses of seismic structure. In comparison, near-fault ground motion records in-cluding directivity pulses are used. The ANN based methods have advantages by providing smaller stroke requirement and damping for TMDs.
|
The increase in the population day by day and urbanization has led to a rapid increase in the construction sector.With the increase in demand in construction, the product types of building materials are increasing.It is seen that wastes are formed during andafter the production of the materials used in the building. This highlights studies on waste management and recycling of waste.After construction activities, wastes are recycled or converted to secondary products.One of these is wood waste, a tra-ditional building material. In addition to the production of wood furniture, it is used in various areas from the beginning of construction to the end of the building. In this study, sawdust, which is the waste of a woodworking company, was used. Utilizing the advantages of wood, recyclable and sustainable cement bonded wood composite production practices have been explored. It is aimed to produce nature and environ-ment friendly, ecological and economic and durable composite materials. In this re-search, it is aimed to determine the optimum ratio by using different ratios of saw-dust-cement while keeping the water-cement ratio constant in production. The spec-imens taken from the production were exposed to high temperature after gaining strength. The strength results, unit weights and ultrasonic pulse velocityresults of cement bonded wood composite samples exposed to high temperature were exam-ined. Although cement bonded wood composites are exposed to high temperatures such as 400°C, it has been observed that strength is achieved. With this study, an al-ternative area was proposed for the evaluation of these wastes.
|
Slope stability analysis is performed in practical geotechnical engineering using the finite element method, which is an advanced method and is widely used by engineers. With the development of computer technology, it has become easy to study the slope's stability supported by frame prestressed anchor and sheet pile wall through the displacement-based finite element numerical analysis method, to calculate the safety factors. However, the expansion angle ψʹ is not widely covered. In this study, PLAXIS two-dimensional finite element method is using to establish the slope model supported by frame prestressed anchor and sheet pile wall, and the influence of ex-pansion angle on slope deformation is studied. The results show that the expansion angle has a differenteffect on the convergence of the two-dimensional slope model. In the model slope, a prestressed frame anchor and sheet pile wall reinforce the slope. The failure mechanisms were unclear when φʹ= ψʹ(flow base). Besides, when the slope has high soil strength parameters (c' or φʹ), the expansion angle will affect the calculation results and convergence. In general, the expansion angle significantly influences the slope's stability and is not affected. Therefore, it was necessary to note the effect of the angle of expansion on stability.
|
In this paper, a comparativeresearch obtaining the time-consuming exact solution and approximate solution of linearly damped linear frame buildings has been carried out. State-space method and mode superposition method are respectively utilized to analyze the exact and approximate vibration solution of frame buildings. In mode su-perposition method, the proportional damping matrix of frame buildings has been constructed in two different schemes, such as modal combination of mass with stiff-ness matrices (Rayleigh) and disregarding the off-diagonal elements of non-classical damping (DOEA) matrix. Meanwhile, the damping matrix in state-space method is non-proportional and constructs in exact circumstance. By imposing different initial conditions on the system, it has been proved that the transient vibration is mostly greater than the steady-state vibration. These observations have individually been investigated to render the approximate response as close as possible to the exact re-sponse. The findings of current research indicate that the most suitable parameter which brings closer the approximate response to the exact response is DOEA ap-proach. In addition, a MATLAB code, which solves the equation of exact and approx-imate method, is generated in this research.
|
Concrete has a significant place in construction structures, is a material that can be
easily damaged due to incorrect design, incorrect material selection. Concrete may
be damaged by physical and chemical factors. One of these factors is the alkali-silica
reaction (ASR). ASTM C1260, is a short-term test method, and ASTM C227, is a longterm test method, are used to measure effect of alkali-silica reaction. In this study,
the effect of fly ash additive use with 0, 5, 10, 15, and 20 wt.% replacement of cement
was investigated in short- and long-term ASR test methods. For this purpose, while
samples prepared for ASTM C1260 were kept in NaOH solution 14-days, samples prepared for ASTM C227 were waited 360-days in normal water solution. As a result;
mortar bars with 20% fly ash additive ratio were classified as harmless for ASR in
both test methods.
|
Dynamic behavior is one of the most crucial characters in the railways structures.
One of the items which leads to precise identification of the dynamic behavior of railways is the soil depth beneath them. In this paper, an Euler-Bernoulli beam on a finite
depth foundation under accelerated moving load is presented. The dynamic equilibrium in the vertical direction is only regarded in accordance with the factor of finite
beams. In this study, the dynamic equilibrium of the soil in the vertical direction and
the sensitivity of soil depth are considered. The governing equations are simulated
by using Fourier transform method. Eventually, by considering the sequences of
shear waves, and different kinds of damping, displacement of the beam is obtained
for the various acceleration, times and soil depth. As a result, it is shown that, higher
acceleration is not dramatically effective on the beam displacement. Also, foundation
inertia causes a significant reduction in critical velocity and can augment the beam
response.
|
A previously benchmarked finite element model of a previously tested composite
plate shear wall-concrete filled (C-PSW/CF) was used to investigate the influence of
three concrete material models on in-plane cyclic inelastic wall response, using LSDyna. The concrete material models considered were the Winfrith, KCC and CSCM, all
available in LS-Dyna. Wall moment hysteresis, using the three concrete material
models, were obtained and compared. Individual contribution of the steel and concrete to total base moment was investigated for each wall with the three concrete material models. The numerical results obtained using the KCC and CSCM were compared
against the benchmarked results obtained using the Winfrith concrete material model.
Moment contribution of the steel web and the steel boundary on total base moment of
the steel part of the wall and moment contribution of the concrete web and concrete
boundary on total base moment of the concrete part of the wall were individually
investigated. The wall models with the KCC and CSCM concrete models were observed to cannot capture wall pinching which was captured by the Winfrith concrete
model. The wall strength was overpredicted by the CSCM concrete model and predicted reasonably by the KCC concrete model. Average axial stress distribution of the
infill concrete was obtained to investigate wall neutral axis and the maximum attained concrete strength using the three concrete models. Concrete axial stress distribution showed some level of confinement for the concrete models considered.
|
Building codes follow a common concept in designing buildings to achieve an acceptable
seismic performance. The objective underlying the concept is to ensure that
the buildings should be able to resist minor earthquake without damage, resist moderate
earthquake with some non-structural damage, and resist major earthquakes
without collapse, but some structural as well as non-structural damage. This study
aims to evaluate the performance-based seismic to come up with necessary recommendations
for both future practices, essential review, and restoration of existing
structures in Yemen. To do this real case studies incorporated, and nonlinear pushover
analysis is carried out. The analysis results presented and then assessed to find
out the conformity with the required performance. The structural sections assumed
at the beginning of the design, then the design repeated many times to achieve the
selected performance criteria (the plastic hinge properties and the maximum displacement).
|
