Authors:Dimiter ALİTCHKOV Abstract: The analysis of the water use of thedifferent consumers is an important issue for the proper design, performanceand management not only for the water supply and sewerage systems in thebuildings, but also for the urban water infrastructure as a whole. Water use changes with time due to manyclimatic, socio-economic, cultural and technical factors and is tightlyconnected with the development of the society and technologies. When the changebecomes substantial, there is a need of upgrading and verification of thedesign parameters and methods, but also the construction practices andmaintenance requirements as well as the corresponding regulations, so that theybecome adequate with current and future development. Analysis of the differentmethods characterizing the water use in the buildings on quantative basis aswell as the determination of its seasonal, daily, hourly or shorter period oftime variation is made. The advantages and disadvantages of water demandmathematical models are discussed and on that basis of that, a statisticalmethod for estimation of the parameters of hybrid stochastic-regression waterdemand model is recommended to be used. The approach gives contemporarytheoretical basis of water demand on different spatial and temporal scales andcan be used for analysis of water consumption not only in the different typesof buildings but also in the settlements. PubDate: Sun, 01 Dec 2019 00:00:00 +030
Authors:Begum Yurdanur DAGLİ; Yesim TUSKAN, Dilay UNCU Abstract: In this study,fluid-structure interaction problem is investigated by solidity ratio approach.In the first case (Case I) steady flow conditions are defined by using air asfluid. The wind forces acting on the space lattice systems are determined byconsidering the solidity ratio dictated by ANSI/TIA-222-G (Steel Antenna Towersand Antenna Supporting Structures) technical specification. Stability of windtower is analyzed using SAP 2000 software program. In the second case (Case II)unsteady flow conditions are evaluated by utilizing water waves acting onlattice marine structures. Models are occurred two groups as three space framestructures and three porous media models. Hydrodynamic wave forces arerepresented by the Stoke’s Second Order wave theory. Morison equation isemployed to obtain lateral wave forces. The results of computational fluiddynamics are performed by using ANSYS-Fluent software. Solidity ratio is usedto observe vortex effect that is based on turbulence around the structuralmembers. The hydrodynamic forces acting on the marine structures are presentedindependent from configuration, depending on solidity ratio values. PubDate: Sun, 01 Dec 2019 00:00:00 +030
Authors:Kağan CEBE; Can Elmar BALAS Abstract: Coastal areas areheavily influenced by human actions such as urbanization of natural andagricultural areas. Besides pollution loads in discharges of the urban andindustrial wastewater, loads washed off from the land are the main sources ofcoastal pollution, both of which can have deteriorating effect for theenvironment. The point and non-point pollutants have become a growing concernfor Davutlar bay, a tourism district in the eastern Aegean Sea urbanized in thelast decades. In order to reduce the pollution in the bay, the construction ofa wastewater treatment plant has started in 2013. In this study, the surfacedischarges from the surrounding basin towards the bay are modelled and thepollutants buildup in surrounding basin are calculated by using EnvironmentalProtection Agency’s Storm Water Management Model (SWMM) for the year 2018considering different landuses defined in the CORINE system. The wastewaterpollutants, namely total suspended solids (TSS), biological oxygen demand(BOD), chemical oxygen demand (COD), total nitrogen (NT) and total phosphorus(PT); discharged from the urban area tothe bay are calculated before and after the wastewater treatment plant began tooperate in 2018. The effects of land-based pollutants and the reducing effectof the wastewater treatment plant for the coastal pollution are discussed inthe projections for the year 2019. PubDate: Sun, 01 Dec 2019 00:00:00 +030
Authors:Ayşe EDİNÇLİLER; Yasin Sait TOKSOY Abstract: Shallowfoundations on the weak soils result in low bearing capacity and/or excessivesettlement problems. This can cause structural damage, reduction in thedurability, and/or deterioration in the performance level. Some of the soilimprovement methods are to replace the weak cohesive soil by a strongergranular fill or to increase the dimensions of the footing, or a combination oftwo. Recently, the use of reinforced soils under the shallow foundations hasreceived considerable attention. The beneficial effects of reinforcements infoundation applications have been studied by several investigators. Inaddition, the use of geosynthetics under foundations is an innovative andalternative way of absorbing the seismic energy and mitigate excitationstransmitting to upper layers of soils and foundation of overlying structures.This comparative study presents the results of numerical simulations of mediumrise buildings on unreinforced and reinforced sand foundation to investigatethe effects of earthquake characteristics and reinforcement length to mitigatethe earthquake hazards of medium-rise buildings. Various reinforcement lengthsin terms of foundation length “B” have been decided. The study has been carriedout by using a finite element code, PLAXIS 2D. Numerical results revealed thatthe geosynthetic-reinforced sand is quite an effective method to mitigate theseismic performance of the mid-rise buildings and earthquake characteristics inaddition to the reinforcement zone play a very important role by means ofseismic performance. PubDate: Sun, 01 Dec 2019 00:00:00 +030
Authors:Ali ALMUSAWI Abstract: In order toobtain a better performance, different modifiers types have been adopted tocomplement the rheological characteristics of the bitumen used in the asphaltroad construction. To bring the asphalt mixture to the desired workability,bitumen and aggregate must be heated at an elevated temperature before mixing.Thus, estimating mixing and compaction temperatures is necessary to achieve therequired performance. The equiviscous method (ASTM D 2493) has been developedthrough the bitumen viscosity measurement to calculate the required mixing andcompaction temperatures. But a problem with excessive temperatures resultedthrough the implementation of this method when it is applied for the modifiedbitumen. Insufficiency of the equiviscous method led to a necessary need toinvestigate for an alternative method which should be more applicable for themodified bitumen. In this study, two methods named Zero Shear Viscosity (ZSV)and Steady Shear Flow (SSF) have been examined to measure the applicability forthe modified bitumen. For this purpose, 50/70 bitumen grade was modified with5% elastomeric type – Styrene Butadiene Styrene (SBS), and 1.5 % ReactiveElastomeric Terpolymer type – Elvaloy (RET). The results have shown that theapplication of the new alternative methods resulted in lower mixing andcompaction temperatures for the modified bitumen. PubDate: Sun, 01 Dec 2019 00:00:00 +030
Authors:Mohammad BEYKZADE; Sepide BEYKZADE Abstract: Studieshave shown that the building industry has the largest share in naturalresources consumption and has the greatest effect on the natural environment.Increasing human awareness of environmental issues, degradation and reductionof natural resources, global warming and rising pollution levels, along withsocial problems, lead to more stringent laws in this regard so that activistsin the construction industry pay more attention to environmental issues.Building performance is today the most important concern of actors in thebuilding industry. In this regard, achieving sustainable performance in linewith the sustainable environmental development has been considered. Sustainableperformance is based on acceptable environmental level, reasonable costs andtechnical feasibility of construction methods and such cases that should be inline with the comfort of the inhabitants. Today, green buildings are theleaders of sustainable development and balance among issues related to theenvironmental, economic and social health. It can be said that green buildingsare a subset of sustainable buildings that emphasize those projects thatconsider the particular importance of solar energy, lighting and ventilation,reduced consumption and the use of recyclable PubDate: Sun, 01 Dec 2019 00:00:00 +030
Authors:Mustafa KARASAHİN; Erdinç KESKİN, İlker ŞAHİNOĞLU Abstract: Theperformance of the superstructure in the transportation structures (railway,highway etc.) is directly affected by the characteristics of subgrade. However,it is not always possible to find the desired quality subgrade soil in theareas where both highway and railway routes. In such cases, it is an option toimprove the problematic soils in place by using additives (lime, cement etc.).The aim of this study is to investigate the effect of lime on the unconfinedcompressive strength (UCS) of a low plasticity clayey soil under differentcuring time (0, 1, 7 and 28 days) and different curing conditions (in adesiccator and soaked). Firstly, geotechnical tests (classification andcompaction) were conducted to determine properties of soil. UCS test samples atfive different lime contents (2%, 3%, 4%, 5% and 6% by weight) were preparedand cured in desiccator. Then UCS test was conducted immediately at the end ofthe curing time. On the other hand, the optimum lime content by weight wasdetermined as 4 % by using the pH method. After curing time in the desiccator,the samples prepared with optimum lime content were soaked in water for 4 daysand then UCS test was carried out. As a result, with the addition of lime,maximum dry density values decreased, optimum water content values increased.UCS significantly increased with both lime content and curing time. For 28days, soaked UCS of the samples prepared with 4% optimum lime content decreasedby approximately 50% according to unsoaked condition PubDate: Sun, 01 Dec 2019 00:00:00 +030
Open Access journal
