Civil Engineering Research Papers - Academia.edu (original) (raw)

Stability of multi-story one-bay space pallet racking system studied experimentally and theoretically to obtain the buckling length and the critical load for the upright of the racking system considering the beam-column connection, and... more

Stability of multi-story one-bay space pallet racking system studied experimentally and theoretically to obtain the buckling length and the critical load for the upright of the racking system considering the beam-column connection, and frame bracing pattern. Five samples of space pallet racking system are studied to obtain the critical load and buckling lengths with different cases of loading, in addition two samples of short upright of the racking system are investigated under axial compression loads to carry out the upright capacity. The experimental results are re-evaluated using both the American Code of Racking (RMI 2012), and the European code of Racking (EN15512), moreover the investigated system are modeled and analyzed using SCIA Engineer software. The modes of failure of the experimented samples are recorded and evaluated. The experimental program has been conducted on the pallet racks using full-scale models.

ABSTRACT Nowadays, drainage networks, whether that was wastewater or storm water drainage networks are considered as one of the necessary infrastructure basics in modern cities. This research is focusing on planning and designing one... more

ABSTRACT
Nowadays, drainage networks, whether that was wastewater or storm water drainage networks are considered as one of the necessary infrastructure basics in modern cities. This research is focusing on planning and designing one drainage network “for a dual purpose” instead of the two networks that used one for wastewater and the other one for rainwater drainage, as they are called separated Drainage networks. Therefore, this network is working on wastewater and on the rainwater drainage on the same time. That reduces the cost by reducing amount of excavations and number of the pipes as well the wages for the workers who work on that project. This network would be perfect in Arab countries like Iraq because the amount of the rainfall is not that much and it happens only on the winter season for almost two or three months, not like the other western countries or Australia.
This research is following the global standardization in finding the optimal way of the designing a network such as finding the pipe slope and velocity of the water inside the pipes. Also, to compare it with minimum and the maximum velocity permitted, as well as finding the discharges and levels of pipes’ places in trenches and that depending on essential principles of designing of the network.
The research also includes the planning, designing and drawing a typical longitudinal sections for the Arab city and to be considered as a model that could be used for the planning and designing for any other cities according to the least possible cost.
All in all, the most important characteristic of this research is to adopt the discharging of more than a pipe in one direction within the inspection room so as to minimize the amount of excavation and reduce the diameters of the large pipes. For example, instead of choosing a pipe with a large diameter we can use two or more pipes with less diameter and that consider as a special feature worthwhile when you do not desire to the use of large diameters or the unavailability of that kind of pipes.

Hydraulic jump is a phenomenon caused by change in flow from super-critical to sub-critical flow with considerable energy dissipation and rise in depth of flow. This paper presents the results of experimental investigations to control the... more

Hydraulic jump is a phenomenon caused by change in flow from super-critical to sub-critical flow with considerable energy dissipation and rise in depth of flow. This paper presents the results of experimental investigations to control the hydraulic jump by providing the abrupt rise (hump) at the bed of rectangular open channel. Various types of humps were designed and fabricated based on the critical velocity analysis for the maximum discharge in the flume. These humps were placed in flume at different positions from the upstream gate to control the hydraulic jump at the downstream. From the experimental results a new relationship is proposed to control the hydraulic jump at a specified location using the hump in the bed. This gives the economical solution in agricultural field which is one of the major contributions towards the society as well as it also gives technical inputs to the researchers in the field of same research. I. INTRODUCTION A hydraulic jump is a phenomenon which has extensively been studied in the field of hydraulic engineering due to its frequent occurrence in open channel flow such as rivers and spillways. When the rapid change in the depth of flow from a low stage to high stage, the result is usually in the form of an abrupt rise at water surface, this local phenomenon is known as Hydraulic jump. By utilizing characteristics, hydraulic jump is immensely used as an energy dissipater to dissipate the excess energy of flowing water at the downstream of hydraulic structures such as spillways and sluice gates, to recover head or rise the in water level on the downstream side and thus maintain high water level in the channel for irrigation or other water distribution purposes. It is useful for increasing weight on an apron to reduce the uplift pressure under a masonry structure by raising the water depth on the apron, to increase the discharge of a sluice by holding back the tail water, to indicate special conditions of supercritical flow and of control section to decide the perfect location of gauging station, for mixing of chemicals, to remove air pockets from water supply line and to prevent water locking etc. Due to these many practical applications, hydraulic jump is an interesting topic that has caught the imagination of many researchersin 18 th century who had done the first experimental investigation of jump to till date. But the control of the jump and its location to serve all these above mentioned uses is the foremost important task for the investigators. The hydraulic jump can be controlled or affected by the number of appurtenances as baffle blocks, sills, weirs, abrupt rise and drop in the channels. As the flow in the vicinity of these appurtenances is rapidly varied, the velocity distribution is not uniform. And it is difficult to apply the momentum equation to analyze accurately the formation of jump only by means of theoretical basis; therefore for useful design information one has to rely on the experimental investigations [1]. The researchers had done laboratory experiments to develop empirical relations for universal applications and model studies were conducted for specific projects. In the 20 th century,many researchershave done experiments on hydraulic jump, amongst them one has done model study with dual spillway [2], one of them had thrown a light on the impact of hydraulic jump [3] and few from the current era; in 2005 one had studied the jump on rough bed [4], in 2011 researcher noticed

Considerably long periods of time are required to measure soil-water characteristic curves using conventional equipment such as pressure plate apparatus or a Tempe cell. A commercially available, small-scale medical centrifuge with a... more

Considerably long periods of time are required to measure soil-water characteristic curves using conventional equipment such as pressure plate apparatus or a Tempe cell. A commercially available, small-scale medical centrifuge with a swinging type rotor assembly was used to measure the soil-water characteristic curves on statically compacted, fine-grained soil specimens. A specimen holder was specially designed to obtain multiple sets of water content versus suction data for measuring the soil-water characteristic curve at a single speed of rotation of the centrifuge. The soil-water characteristic curves were measured for three different types of fine-grained soils. The three soils used in the study were processed silt (liquid limit, wL = 24%; plasticity index, Ip = 0; and clay = 7%), Indian Head till (wL = 35.5%, Ip = 17%, and clay = 30%), and Regina clay (wL = 75.5%, Ip = 21%, and clay = 70%). The soil-water characteristic curves for the above soils were measured in 0.5, 1, and 2 ...

The depleting non-renewable energy sources and its hazardous impact on an environment has forced us to think out of the box and take active moves in the field of renewable energy sources. Conventional Internal Combustion Engines use the... more

The depleting non-renewable energy sources and its hazardous impact on an environment has forced us to think out of the box and take active moves in the field of renewable energy sources. Conventional Internal Combustion Engines use the maximum share of the non-renewable energy sources and as soon as possible we need to find alternatives for the same. In this study, we have designed an Electric Bike which is completely eco-friendly and based on the electric motor concept as an alternative to the Internal Combustion Engine. The selection of batteries and motors while designing such concept totally depends on the desired output or the working load conditions. This dissertation concentrates on designing and analysing the frame of a two-wheeler, twoseater bike for an electric mobility purpose, while considering strength, safety and optimum performance of the vehicle.

A new approach is developed to determine the shear wave velocity in saturated soft to firm clays using measurements of the liquid limit, plastic limit, and natural water content with depth. The shear wave velocity is assessed using the... more

A new approach is developed to determine the shear wave velocity in saturated soft to firm clays using measurements of the liquid limit, plastic limit, and natural water content with depth. The shear wave velocity is assessed using the site-specific variation of the natural water content with the effective mean stress. Subsequently, an iterative process is envisaged to obtain the clay stiffness and strength parameters. The at-rest earth pressure coefficient, as well as bearing capacity factor and rigidity index related to the cone penetration test, is also acquired from the analyses. Comparisons are presented between the measured clay parameters and the results of corresponding analyses in five different case studies. It is demonstrated that the presented approach can provide acceptable estimates of saturated clay stiffness and strength parameters. One of the main privileges of the presented methodology is the site-specific procedure developed based on the relationships between clay strength and stiffness parameters, rather than direct correlations. Despite of iterative processes, the presented approach can be easily implemented using a simple spreadsheet, benefiting both geotechnical researchers and practitioners.

Due to its prevalence in modern infrastructure, concrete is experiencing the most rapid increase in consumption among globally common structural materials; however, the production of concrete results in approximately 8.6% of all... more

Due to its prevalence in modern infrastructure, concrete is experiencing the most rapid increase in consumption among globally common structural materials; however, the production of concrete results in approximately 8.6% of all anthropogenic CO2 emissions. Many methods have been developed to reduce the greenhouse gas emissions associated with the production of concrete. These methods range from the replacement of inefficient manufacturing equipment to alternative binders and the use of breakthrough technologies; nevertheless, many of these methods have barriers to implementation. In this research, we examine the extent to which the increased use of several currently implemented methods can reduce the greenhouse gas emissions in concrete material production without requiring new technologies, changes in production, or novel material use. This research shows that, through increased use of common supplementary cementitious materials, appropriate selection of proportions for cement replacement, and increased concrete design age, 24% of greenhouse gas emissions from global concrete production or 650 million tonnes (Mt) CO2-eq can be eliminated annually.

Increased flooding in recent years indicates that most parts of the country are subjected to periodic and destructive flood attacks. Therefore, the identification of high-risk areas with potential runoff production within a watershed area... more

Increased flooding in recent years indicates that most parts of the country are subjected to periodic and destructive flood attacks. Therefore, the identification of high-risk areas with potential runoff production within a watershed area is one of the most important measures in flood control and reduction of the damage caused by it. In this study, the quasi-distributional ModClark method was employed to simulate the hydrograph of flooding, and the unit flood response method was applied to determine the intensity of flooding of different areas of the Tangrah watershed, Iran. For this purpose, the ModClark model was first calibrated and verified. Thereafter, the design of rainfall with 50 and 100-year return periods (T r) was extracted at the Tangrah station and the design flood was calculated with the above-mentioned return periods. By combining the curve number layers, slope, precipitation, and flow distance, homogeneous units were obtained in terms of the flood. The effect of each homogeneous unit on the total watershed output was obtained by the removal of each unit and implementation of the rainfall-runoff model. According to the 100-year return runoff production potential, homogeneous units of 116 with a fi (0.54 m 3 / s. km 2) were identified as the most effective cell in the Tangrah watershed area, which could be explained by the soil type, vegetation, and other physical factors of these units.

Climate change and demographical increase in developing countries are inducing us to reconsider the way we build the buildings. Concrete and steel have already reshaped our cities for 2 centuries but problems related to the... more

Climate change and demographical increase in developing countries are inducing us to reconsider the way we build the buildings. Concrete and steel have already reshaped our cities for 2 centuries but problems related to the non-sustainable aspects of steel and concrete are now appearing in their productive system, characteristics, creation process and energy demands. It is necessary to find new solutions, especially regarding high-rise buildings which will be one of the main typologies of construction in a more and more urban future scenario. The only structural material that can tackle the future demand of building is wood as Mass Timber Products. There are already several successful examples of how this material could answer architectural challenges. As architects, we have the power to choose how the building is built and realized. On our profession stands a great chance to increase the realization of sustainable buildings. Since the beginning of mankind, wood structure was one of the most common types and this trend was decreased only in the last 2 centuries thanks to the rise of steel and concrete structures. The 21st century can be instead the century of the renaissance of wood an the motifs are really a lot. Sustainable, renewable, zero impact and other qualities certified that it must be considered as possible solution. The context of the competition Wien Heiligendstadt Wohnen und Arbeiten is a pretext to show how an international competition can adopt Mass Timber as technological solution compared with a concrete solution. Showing the plus points and demerits of wood as a structural material is the main aim of this Master Thesis. Additionally, this Master Thesis aims to demonstrate the feasibility of an on field context rather than a theoretical solution, while also displaying the current status of wood technology.