Yer yuzunun guclu titresimlerini incelenme ve analizi yapi muhendisligi (yapi davranis analizi) ve deprem muhendisligi ( zemin davranis analizi) iki muhendislik dalinda onem tasimaktadir. Bu arastirmada faya yakin olan depremler soz konusudur. Genel olarak 15 km den yakin olan depremler faya yakin ve 15 km den uzak olan depremler faydan uzak depremler denilir. Faya yakin depremler daha yuksek frekans ve daha yuksek ivmeye sahiplerdir. Faya yakin depremler de etken suresi daha az ama daha etkilidir. Sundan dolayi rijit yapilar icin daha esnek yapilar tasarlamak gerekmektedir.
This research is carried out to investigate and assess the critical role of soil properties and their content in influencing the soil liquefaction phenomenon that takes place when an earthquake happens. A case study is taken into account in this work, representing the Karakaya Dam. Two research approaches were implemented to achieve the research goal, including extrapolation in Excel and numerical optimization using linear regression. The outputs revealed that the annual temperature in the future of zones around the Karakaya Dam, including Azami, Ortalama, and Asgari, would witness a moderate increase of about 3 to 6 degrees Celsius next decade. Moreover, the research confirmed that the Euphrates River discharge rate at the Karakaya Dam would witness a significant increase from (100-350 m3) to (2,590-2,640 m3) in 2029, explaining that temperature and discharge rate may influence the liquefaction. Meanwhile, the research outputs indicated that soil temperature under the Karakaya Dam and chemical elements would not variate significantly next decade. Notwithstanding, the pH number will change widely from 4.14 to 9.74 in 2029. Besides, the most significant chemical molecule concentration in the soil under the Karakaya Dam is the phosphite anion, corresponding to a minimum and maximum concentration of 1 and 2 μg/m2, respectively.
Fixed offshore jackets are principal substructures widely used in offshore industries. An accurate consideration in finding an advantageous alternative to traditional steel material in the construction of this essential structure could be very efficient. The focus of this study is to simplify the construction procedures and to increase the serviceability life of the offshore jacket. To this aim, as a new low-cost material, high-specific-strength steel has been considered. With using ANSYS software, transient dynamic analysis has been implemented on two hypothesized three-legged jackets located in the Persian Gulf region. It is assumed that the modeled jackets are made of traditional steel and high-specific-strength steel material. The effects of an extreme wave load and a supply vessel impact load have been considered for the structural analysis. It has been shown that structural performances of the high-specific-strength steel jacket under the effects of the mentioned loads, are better compared to the traditional steel jacket.
A total of four reinforced concrete (RC) columns were tested to compare the structural capacities of RC columns produced by natural perlite aggregates and conventional concrete. The structural performance of the RC columns made from natural perlite aggregates was compared to conventional RC columns regarding the same concrete strength levels, sectional properties, and reinforcement layouts of conventional RC columns. The RC columns were tested under a combined constant axial load ratio of 30% with cyclic loading for two concrete strength levels, namely, 25 and 40 MPa. Load–displacement curves, energy absorption capacities, stiffness degradation, the moment-curvature relationship, the plastic hinge mechanism, and the ductility index were experimentally obtained at two different concrete types along with the measured stress–strain properties of the conventional and perlite concrete. The test results showed that the construction of the RC columns using only perlite may become possible in the future by providing an adequate concrete stress–strain capacity, which will be improved. Additionally, the use of natural perlite aggregates can contribute to sustainable construction practices by reducing the reliance on conventional aggregates.
Since the earthquakes in Northridge and Kobe in 1994 and 1995, respectively, many investigations have been carried out towards improving the strength and ductility of steel beam to column pre- and post-Northridge connections. In order to achieve these objectives, recent researches are mainly focused on three principles: reducing the beam section to improve the beam ductility, adding different kinds of slit damper to beam and column flanges to absorb and dissipate the input earthquake energy in the connection and strengthening the connection area using additional elements such as rib plates, cover plates, and flange plates to keep the plastic hinges away from the column face. This paper presents a reduced beam section approach via the introduction of multilongitudinal voids (MLV) in the beam web for various beam depths varying from 450 mm to 912 mm. ANSYS finite element program was used to simulate the three different sizes of SAC sections: SAC3, SAC5, and SAC7. Results showed an improvement in the connection ductility since the input energy was dissipated uniformly along the beam length and the total rotation of the connection was over four percent radian.
Sewage sludge is a product of wastewater treatment plants.This study aims to evaluate adding different percentages of sewage sludge as a weight ratio to gypsum soil to develop some physical and mechanical soil properties.Samples of soil were obtained from the city of Ramadi, and the sewage sludge was accumulated directly at the Al-Rustamiyah wastewater treatment plant located north of Baghdad, Iraq.The laboratory experiment was undertaken on the original gypsum soil samples and the soil treated with sewage sludge ash.This study also involves testing XRF and energy-dispersive X-ray spectroscopy (ESD) of the sewage sludge material.There was a rise in the liquid limit and plasticity index for Atterberg limits.The compaction results indicated increased maximum dry density and optimal moisture content.The optimum unconfined compressive strength (UCS) value is obtained by adding 20% of sewage sludge.The best maximum dry density was achieved with 20% sewage sludge ash.After adding sewage sludge ash, the dry density of gypsum soil increased significantly to 1.65 g/cm 3 .Also, the optimum water content is gradually increasing.The bearing capacity ratio for the untreated soil was 5%, and the California Bearing Ratio (CBR) values were recorded as 22.3% for the gypsum soil treated with SSA at 20% with a curing time of 14 days.There is a significant increase in cohesion values with between 10 and 20 percent of the sewage sludge added to the soil.This increase has a significant effect on engineering soil behaviour.The elements are found in sewage sludge ash, based on XRF, EDS, and SEM tests: Si (10.5%),Al (3.6%), Ca (15%), and Fe (6.2%).Sewage sludge can be used successfully as an additive to improve the properties of gypseous soils by a weight ratio of 20%.
The construction industry has been broadly developed and improved over the last decades.One of the functional innovations in this sector is the employment of steel fibers.This work assesses the impacts of using Steel Fiber Reinforced Concrete (SFRC) on the properties of hollow-core slabs.The hollow core slab (HCS) is considered in this research.Also, this study explored the influence of utilizing some SFRC fractions on the characteristics of hollow-core slabs.Four case studies were addressed, including (A) Conventional concrete, (B) Concrete with Type 1 SFRC, (C) Concrete with Type 2 of SFRC with a ratio of 0.5%, and (D) Concrete with Type 2 with a portion of 1%.ANSYS software package was used to guide numerical analysis and modeling of HCS and identify major parameters that affect the HCS performance with the help of Finite Element Analysis (FEA).Depending on the numerical results, it was found that using SFRC between 0.5% and 1% in concrete tubes tested numerically provided significant rates of durability, minimized deflection, and enhanced the mechanical behavior of concrete.Furthermore, the work outcomes confirmed that optimum displacement was attained when the SFRC ratio was 1.5%, corresponding to load values of 25 kN to 200 kN.Besides, the findings affirmed that using the first type of SFRC accomplished a considerable decline in the deflection of concrete.Deflection reduction ratios of 4.16% and 6.23% were obtained after adding the first and second types of SFRC into the reinforced hollow concrete core, respectively.Meanwhile, adding the first and second types of SFRP into non-reinforced hollow concrete core accomplished a reduction portion of 12.2% and 20.39%, respectively.
In die-casting molds, heat-checking is the typical failure mechanism. Optimizing the parameters that decrease this failure venture should be considered when designing and heat treating steels. The quality of die steels and their treatment continue to improve. This research investigated properties of the traditional materials 1.2343 and 1.2344 and the new steels (Dievar and TOOLOX 44) when applied to the die-casting mold specimens, after different experimental cycles. Also microstructures of the mentioned materials were analyzed by scanning electron microscopy (SEM) test. Chrome-molybdenum-silicon-vanadium steels have good hardening ability in oil and in air. Therefore, the hot-work steels have considerable toughness and plastic attributes through both regular and higher temperatures. So, it is a good traditional die-casting material. However, another special die steel, such as Dievar, is a particularly developed steel grade; its exclusivity profile is exceptional due to its chemical composition and the use of the latest production techniques. Dievar has good heat-checking and gross-cracking resistance as a result of both high toughness and good hot strength. An additional material, a new prehardened tool steel known as TOOLOX 44, exhibits control of the failure described above by optimizing the parameters of impact toughness that could reduce the heat-checking failures. A variety of heat treatment parameters exist for various reasons because the heat treatment operation is performed by a variety of companies. This issue of the diversity in heat treatments is resolved by TOOLOX 44; this steel is quenched and tempered in delivered state.
Sustainable construction has evolved into a global priority to mitigate the impacts of climate change, as the construction industry significantly contributes to environmental degradation and the overexploitation of resources. This study considers the effects on sustainability, particularly the inadequate management of resources, the ecological impact, and the anticipated degradation of the structures, all of which are due to the omission of the structural analysis during the design phase of the reinforced concrete (RC) structure. A methodical survey was conducted in three major cities among 258 professionals in the construction sector in Burundi, a developing country that has suffered socio-political and infrastructural challenges. The study examines the impact of these challenges on construction results. Quantitative analysis was carried out using SPSS v.30 and Amos 26 Software. For this research, reliability analysis, Kaiser-Meyer-Olkin test (KMO), Bartlett test, Exploratory Factor Analysis (EFA), Principal Component Analysis (PCA), and the Relative Importance Index (RII) were used to ensure the reliability and accuracy of the data. The results indicate that many projects are taking place in the absence of proper structural analysis due to financial constraints, poor quality materials, lack of qualified personnel, poor enforcement of regulations, and insufficient monitoring. These parameters have led to structural deficiencies compromising sustainability. The study recommends that government agencies, professional construction workers, and building owners improve regulation, teaching effectiveness, and professional responsibility to ensure that fundamental practices, such as structural analysis and the use of right sustainable materials, are logically applied to improve public safety and environmental resilience.
Journal Article Evaluation of a New Method for Cardiovascular Reasoning Get access William J. Long, PhD, William J. Long, PhD Affiliations of the authors: MIT Laboratory for Computer science, Cambridge, MA (WJL); New England Medical Center and Tufts University, School of Medicine, Boston, MA (SN, MGC) Correspondence and reprints: William J. Long, PhD, MIT Laboratory for Computer Science, 545 Technology Square, Room 420A, Cambridge, MA 02139. Search for other works by this author on: Oxford Academic PubMed Google Scholar Shapur Naimi, MD, Shapur Naimi, MD Affiliations of the authors: MIT Laboratory for Computer science, Cambridge, MA (WJL); New England Medical Center and Tufts University, School of Medicine, Boston, MA (SN, MGC) Search for other works by this author on: Oxford Academic PubMed Google Scholar M. G. Criscitiello, MD M. G. Criscitiello, MD Affiliations of the authors: MIT Laboratory for Computer science, Cambridge, MA (WJL); New England Medical Center and Tufts University, School of Medicine, Boston, MA (SN, MGC) Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of the American Medical Informatics Association, Volume 1, Issue 2, March 1994, Pages 127–141, https://doi.org/10.1136/jamia.1994.95236144 Published: 01 March 1994 Article history Received: 06 July 1993 Accepted: 10 November 1993 Published: 01 March 1994
In Iraq, there is a vast construction movement. Still, it is accompanied by many problems, the most important of which is the delay in completing projects during the specified time. The time must be optimized by adopting the leadership practice and dedicating it to the benefit of performing the process and functions of the project. The research aims to identify the most important reasons and factors that affect the project delivery process within the specified period. The investigation initially dealt with the most important previous studies, on this subject, by researchers, then touched on the concept of construction projects, their types and details. A questionnaire containing reasons for the delay was identified and divided into several items. It concluded that the most common reasons for delays are delays in laboratory testing of materials, assignment of works to the lowest bidder, contractors' financial incompetence, and high building materials prices. The most crucial factor is to streamline building material inspection procedures, set up inspection laboratories on several occasions and assess the contractor's effectiveness and ability to implement before the project is referred financially. Organizations and individuals should coordinate their work between the construction departments to prevent any issues that may arise during completing tasks.
Although water has an indispensable place for people to survive, it is a destructive substance that has negative effects for structures. Although the places that need the greatest strength in the structures are the basics and basements, the water that does the greatest damage to the structures is the groundwater that affects the foundations and basements. For this reason, underground water protection systems should be applied in the structures. If necessary studies are carried out and precautions are not taken, groundwater affects the structure in various ways and causes adverse situations in the structure over time. Waterproofing practices that are not made or miscarried significantly reduce building life, threaten human safety and health, cause irreversible problems in building safety. Therefore, what protection systems against groundwater systems, system characteristics, uses and principles are discussed in the structures. Accordingly, the materials used in waterproofing applications are classified and their characteristics, application procedures and bases are explained. This study will help learn material classes and uses and will soliden the choice of accurate waterproofing practices and materials.
All around, civil engineering megaprojects are still struggling with budget overruns, schedule slippage,and disjointed supply-chain coordination. This paper conducts an embedded, multiple-case study ofpublicly recorded projects spanning Asia, Africa and the Middle East. Using a pragmatist mixed-methodsapproach, we thematically coded secondary reports, audits and peer-reviewed case narratives;descriptive statistics were used to investigate related cost- and time-performance data. Convergenttriangulation found four common levers distinguishing better performers, early strategic alignmentamong stakeholders, proactive scenario-based risk management and digitally enabled transparencythrough (BIM) and (IoT) twins. Collaborative contracting cultures such as Integrated Project Delivery.Projects using these levers reduced lead-time variation by as much as 17% and cost overruns by 4–6percentage points. Building on these ideas, we suggest an Integrated Lean-Digital Frameworkcascading through Strategic Alignment, Collaborative & Digital Integration, OperationalExecution and Continuous Improvement & Sustainability. Though reliance on secondary datareduces statistical generalizability, deliberate case selection and cross-source triangulation improvetransferability, therefore offering a consistent path to fight fragmentation. This synthesisoffers practical advice for managers and politicians.
This research aims to understand the characteristics of the Tigris River and the possibilities of human use in Baghdad.Samples for this study were collected for analysis from three separate districts in Baghdad, Iraq.Three sites in the upstream, middle, and lower downstream regions of the study area were used to collect river water samples (East Tigris Water Project, Al-Shuhada Bridge Project, and Al-Rasheed Project).To verify that the water is suitable for human needs including drinking water, agriculture, and industry, several tests have been carried out; The study data from the year (2005-2020) PH, Cl, NO3, PO4, SO4, Na, Ec, Ca, K, Mg, TH and TDS are among these tests.And the results of the three projects in the water characteristics of the Baghdad River.The results showed that SO4 was within the allowed in (East Tigris Water Project, and Al-Shuhada Bridge Project) and was higher than allowed in Al-Rasheed Project, while (PH, NO3, PO4, Ca, TH, and K) were all within the allowed range (Project East Tigris Water, Al-Shuhada Bridge Project).According to the World Health Organization, Ec had readings a few above the permissible levels and the TDS was above the permissible limit.
Planned methods may be developed to improve the efficiency of building construction. The construction business is profoundly impacted by the prevalence of inaccurate cost and schedule prediction. The main strategy to improve the project performance is to evaluate the hybrid sustainable materials using the artificial neural network (ANN) method based on the effective factors in construction projects in Iraq. This strategy needs an effective method to classify the project input representation and specify the accurate activity of each factor. This paper uses a hybrid artificial neural network to correlate and classify the sustainable hybrid of construction projects to evaluate their performance. The contribution of this method is the selection of the Multi-Criteria Decision-Maker method (MCDM) based on time and cost-effective factors correlated with the artificial neural network method. A dynamic selection procedure for project materials may be created using the existing technique as an evolutionary model for successful project completion. The MCDM observed that the appropriate sustainable material was considered as the main factor with a rank of 0.823 for cost effect and 0.735 for time effect and the main influence factor in Iraqi projects was the building height. The results present superior functional cost evaluation results correlated with the selection of hybrid sustainable materials.
