Tishreen University Journal -Engineering Sciences Series,

The field investigation of the influence of deep excavation construction fence on the mechanical and strength characteristics of soil

2023-10-29T22:08:48+00:00

In the course of excavating a thick layer of soft, weak soil in St. Petersburg, Russia, instabilities were encountered in a 21 m long sheet pile excavation fence made of AU Arcelor 18. In light of the rather large depth (12 m) and areal extent (150 m by 80 m) of the excavation, such instabilities presented a significant challenge for the geotechnical engineers. The stability of the sheet pile was increased by constructing vertical and horizontal diaphragms in close proximity by jet grouting. This process can, however, alter the properties of the foundation soil in the vicinity of the excavation fence. To better ascertain how such properties can potentially be altered, excavations involving similar soils from neighboring building were simulated using the PLAXIS finite element program. This paper reviews the results of soil property tests performed in conjunction with the construction of the aforementioned large excavation, as well as the neighboring buildings. The need for continuous monitoring of geotechnical conditions using the methods of static sounding, so as to assess the zone of construction influence and to forecast the mutual influence of the structure being constructed on the surrounding buildings, is discussed.

Studying and Analyzing the Current Situation of Integrating BIM Technology in Engineering Education in Syrian Universities

2023-10-23T07:00:18+00:00

Building Information Modeling (BIM) technology is one of the latest technologies in the construction industry, and has proven to be very useful in improving the quality of engineering project work. Because of the great role that BIM technology plays in the construction industry and the increasing spread of this technology globally, many universities around the world have begun to integrate BIM into their programs and curricula for architecture and construction engineering (AEC). This integration aims to meet the increasing demand from the labor market to prepare engineers who are proficient in this technology.

Despite the global interest in integrating BIM in education, the interest in Syrian universities was limited to some individual efforts by faculty members and some external courses to use BIM programs. Through this research, we aim to study and analyze the current situation of engineering colleges in three areas of initiatives and procedures of the educational institution about BIM, educational process and technological capabilities. A questionnaire was developed and data were collected from 26 faculties of civil and architectural engineering in Syrian public and private universities.

The data was analyzed and a set of recommendations were produced aimed at improving the reality of BIM in engineering colleges and highlighting the challenges that prevent this.

Study on the behavior of monopiles used to founding offshore wind turbines

2023-10-29T21:06:34+00:00

Horizontally loaded piles used in founding electric power generation fans are affected by

wind forces and repeated wave loads applied to them. This research is a computer

modeling and analytical study of a loaded monopile pile which is used as a foundation for

a offshore wind turbine fixed in a medium compacted and compacted sandy soil (sea

bed). In this research is Hardening Soil model (HS) used for the soil surrounding the pile.

The horizontal displacement values are determined due to several parameters. It is shown

that the horizontal displacement of the monoopile is controlled by several parameters

such as: its embedded length, its diameter, the height of the sea water, the value of the

total horizontal force and its arm Calculations show that cyclic loading increases the

horizontal displacement by 30%, and that the soil subgrade reaction coefficient

distribution.with depth is not linear in sandy soil and Rees’ method for calculating

horizontally loaded piles is not very suitable for monopile piles, especially in the

displacement and moment distribution diagrams .

CFD study of the hull-propeller interaction in marine vehicles under different sailing conditions

2023-11-20T21:05:17+00:00

This research used CFD technology to study the hull-propeller interaction of two different types of marine craft under different sailing conditions (with and without drift angle). The study was conducted on a JBC (Japan Bulk Carrier) and DARPA Suboff submarine models. Initially, a comparison was made between the numerical and the available experimental results for the total resistance and velocity field to ensure the accuracy of the CFD settings and equations used. The comparison confirmed that there was great agreement between the results. The ship and the submarine were then studied alone without the propeller, aiming to know and analyze the velocity, pressure, and vortex field around the marine craft without the propeller. Then, the propeller was added, and the effect of the presence of the working propeller on the characteristics of the flow field and the formed vortex system was studied. The URANS (Unsteady Reynolds Averaged Navier Stokes Equations) method and the K-Ꞷ SST turbulence model were used to solve the Navier Stokes equations within the ANSYS program, in addition, the mesh motion feature was used to calculate the interaction between the hull and the propeller.

Studying the Effect of Using Rapid Modeling (RP) in Manufacturing Brushes as an Alternative to the Traditional Manufacturing Process

2023-09-25T20:07:06+00:00

During this research, We designed lathe bed from two sheets depending on sheets system which used in rapid prototyping, so that we can detective some of aids: reducing the economic effects of the friction and wear in order to achieve the best mechanical properities, and reducing costs of the required materials to make the damaged parts and costs of the maintenance.

And taking advantage of Catia program, and finite element method, lathe bed meduim sized, type ZMMC400TN, weight is 700kg, and force is 15KN.

We have passed researching in accordance with the following main points:

Conduct comparian between two cases of the lathe bed, which the first case is making from Cast iron, and the second case is making from two sheets( depending on Rapid prototyping) steel and cast iron.
Conduct comparian between three cases of the lathe bed in terms of deformation, stress distribution on the axis , von misses stress and bed weight which the first case is making from cast iron, and the second case is making from steel and the three case is making from Ipoxy granite.
Conduct iconomic comparian between two cases of the lathe bed depending on results of the plans and rapid prtotyping principle.

And we have reached the following results:

Potential manufacturing the bed from two or more materials according to the number of suggested sheets, and replaced the cast iron with less expensive materials and best mechanic properties.
Reducing the friction and wear effects on surface according to the bed material, and reducing the stresses applied on the surface thereby achieve longer life of the bed whithout damage.
Achieve saving in maintenance costs of the damaged parts and saving in the time required for maintenance.

Using the Ordinal Regression in the Probabilistic Analysis of Seismic Vulnerability for a Model of Concrete Bridges

2023-09-16T05:46:11+00:00

The increasing interest in seismic fragility curves and in developing them to be more effective and useful requires the use of statistical and probability techniques different from those used in the traditional case, so in this research we used an unfamiliar statistical method in this field, which is the ordinal regression. We adopted the analytical method to create seismic fragility curves for a class of concrete bridges, where a sufficient number of samples of bridges belonging to this class were analyzed using csibridge v20 software, and damage data were collected in each of them for different seismic intensities, then the damage data was processed based on five different models of ordinal regression then the corresponding fragility curves were plotted. The research showed that the ordinal regression with its five models used in this research is well suited to constructing seismic fragility curves for the studied class of bridges with some variation in the quality and fitness of the five models, but they are all acceptable.

Evaluation of the impact of spatial accuracy of satellite imagery and supervised classification algorithms on the accuracy of land cover maps - Case study: Latakia Governorate.

2023-11-12T05:05:27+00:00

Remote sensing technology is considered one of the most effective methods for obtaining land cover maps, which are produced by applying satellite image classification techniques that are influenced by factors.

In this research, the impact of the type of classification algorithm and the spatial resolution of the satellite image used on the accuracy of the land cover map for a part of Latakia Governorate was studied. The supervised classification was applied with Maximum Likelihood, Mahalanobis distance, and minimum distance algorithms on Landsat 8 satellite image and Sentinel A image after resampling at resolutions of 15m and 10m, respectively.

The results showed that the Maximum Likelihood algorithm is the most accurate in classifying the Sentinel 2A satellite imagery for land cover mapping, with an overall accuracy of 88.2% and a kappa coefficient of 0.81. As for Landsat 8 imagery, the Minimum Distance algorithm was the most accurate, with an overall accuracy of 83.3% and a kappa coefficient of 0.79. On the other hand, the results indicated an improvement in the overall accuracy values for all algorithms with increasing spatial resolution of the classified imagery. The overall accuracy increased from 80.1% to 88.2% for the Maximum Likelihood algorithm, from 78.2% to 80.9% for the Mahalanobis Distance algorithm, and from 83.3% to 85.3% for the Minimum Distance algorithm. We also observed an improvement in the kappa coefficient values from 0.75 to 0.81 for the Maximum Likelihood algorithm, from 0.71 to 0.75 for the Mahalanobis Distance algorithm, and from 0.79 to 0.80 for the Minimum Distance algorithm. Finally, the results indicated that with increased image spatial accuracy, there is less overlap between class ranges, resulting in a reduction in misclassification of certain pixels.

Classification Of Network Load Traffic By taking advantage of Software Defined Network

2023-10-24T21:33:49+00:00

The current networks are experiencing exponential growth in network loads due to the rapid emergence of numerous network applications. As a result, networks have transitioned into the era of massive data centers and evolving patterns of network loads. This necessitates more efficient and effective network management techniques, particularly for monitoring network loads. This is where Software Defined Networks (SDN) come into play. SDN provides the advantage of centralized control by separating the control layer from the data layer.

A significant challenge within the realm of SDN is the efficient classification of network load traffic to facilitate improved resource allocation and management. This paper categorizes network bearer traffic into two distinct categories: large traffic, often referred to as "elephant," and small traffic, known as "mice." Subsequently, we directed the large loads along a different route than the core network route. The results underscore the importance of the employed methodology in enhancing the load transfer process within the network.

The Interaction Forces Between Frame and Shear Wall Parts of Optimally Designed Seismic Resistant Highrise Dual System R/C Building

2023-11-06T18:34:05+00:00

Dual systems are of high efficiency in resisting lateral loads under seismic events for high-rise reinforced concrete buildings. As the two parts perform the dual action and both have different deformation modes, the walls are stiffer than the frames and deforms in bending mode, while the frames restrain the shear wall in upper stories because they deform in shear mode. The resulted difference in deformation gives this system the adequate rigidity to resist lateral deformation along the building’s height. But this interaction forces between the two parts might induce an extra demand on the sections of both parts and likewise the cost might rise. This research puts an assumption that as long as the design of the dual system is optimized under a cost objective function, the interaction forces between the two parts would decrease, and this might give several indications and design guides to be fulfilled when designing a dual system. Upon analytically modeling the dual system of this research and performing analysis to optimally design the building of it the results showed that the assumption is correct, and indeed the optimum design of this building gave the lowest interaction forces between the two parts.

Contribution to Analysis and Evaluation the Chemical, Physical Properties of Construction &Demolition Wastes & Aggregates

2024-01-31T09:08:33+00:00

Construction &Demolition Wastes are widely recognized as the main waste stream around the word, and their recycling and recovery is a main issue in many studies and researches of Organizations and Academic centres. In spite of good performance of recycled C&D in general, it is still outspread in our Country.

The composition of Construction &Demolition Wastes is highly heterogeneous and is influenced by several factors, including the raw materials and construction product used. The performance of these materials is considerably variable, and in some cases don’t comply with the environmental regulations.

C&D waste recycling is considered as important issue, especially in the regions of natural disasters and conflicts, which usually lead to huge amounts of C&D wastes.

The research aims to study and evaluate the Chemical, Physical Properties of Construction &Demolition Wastes & Aggregates, to determine their reusing aspects.

Study of the effect of some manufacturing and operating defects on the unbalance of rotating shafts using MATLAB

2023-11-05T09:27:24+00:00

Rotary machines are widely used in mechanical and electromechanical systems that include motor axes, industrial turbine turbines, etc., in the case of an unbalanced distribution of the rotating masses around the axis of rotation, which leads to vibrations, which is a serious engineering problem that negatively affects the performance of these machines, where vibration occurs In any rotating machine due to manufacturing or operational defects, etc., these harmful vibrations are accompanied by the emergence of large centrifugal forces that can lead to damage to the bearings and eventually to the destruction of the machines. Therefore, vibration reduction techniques in such machines are of prime importance to improve performance

. One of the techniques used to improve the work of the rotary shaft is the shaft balancing technique, which is based on reducing vibration to a minimum (as practically vibrations cannot reach zero values), thus increasing the life of the bearings, reducing audible noise and energy loss, and thus improving the work of the rotor.

The aim of modeling and simulation of rotor systems is to study and determine the deflection of the rotating body due to vibration and to calculate the position and additional masses needed to remove the vibration when rotating at high speeds. In this research, we designed a mathematical model used to study the static behavior of rotating axes and to determine deviations at high speeds using MATLAB/SIMULINK software..

Increasing the impact strength and wear resistance of Hadfield steel used in excavator teeth and crusher hammers by adding chromium and molybdenum

2023-07-22T12:34:53+00:00

Work has been done on adding chromium and molybdenum to Hadfield steel, from which crusher hammers and excavator teeth are made. The process of smelting the metals required to form Hadfield steel with chromium and molybdenum in different proportions was carried out according to two meltings, then casting the samples in sand molds and performing rapid cooling in water after casting, then testing the impact, wear and hardness of the samples.

The results showed an increase in hardness and thus an increase in wear resistance. The impact toughness also increased as a result of the addition of chromium and molybdenum. Thus, the resulting steel became more tolerant of heavy service conditions, which leads to economic cost savings in addition to the scientific aspect..

Contribute to determining the quality of groundwater in Damsarkho for use it in operating a heat pump

2023-10-19T14:41:04+00:00

The burning of large quantities of fossil fuels to generate the electricity needed for heating and air-conditioning devices releases large amounts of carbon dioxide which is one of the gases that plays a major role in the greenhouse effect of our atmosphere. It is also expected that energy consumption around the world for air conditioning alone will increase 33 times by the year 2100, which threatens more fossil fuel depletion. In order to address this matter, it was necessary to follow the technology of renewable energies and most importantly, that this technology be of an acceptable cost and high economic feasibility, so that it becomes available to all. The research focuses on the hydrological study that includes the geochemistry of water with regard to its use in the heating and air conditioning circuit as a renewable and sustainable heat source. Therefore, samples were taken from 10 wells that included the parameters (bicarbonate ions, sulfate magnesium, sodium, chlorine and general hardness). It was found that the groundwater in Damsarkho is good and can be used to operate a heat pump for heating and air conditioning purposes.

Study of the Forces Affecting the KVLCC2 Tanker and the Propeller MP687 Using the Verification and Validation Procedure and CFD

2023-09-30T10:11:50+00:00

This research presents a detailed explanation of the Verification and Validation procedure followed in CFD (Computational Fluid Dynamic) and EFD (Experimental Fluid Dynamic) studies. This procedure ensures the method's correctness and the settings used in these studies. V&V was applied to the case of the forces affecting the KVLCC2 tanker and its propeller using the CFD. The URANS (Unsteady RANS Averaged Navier Stocks Equations) and the k-Ꞷ SST turbulence model was used to solve the Navier Stokes equations. KVLCC2 tanker model (Korean Very Large Crude Carrier 2nd Generation) was selected to conduct this study due to the availability of many EFD results for this ship model, which may help us be sure about the quality of the numerical results we will get. Initially, the ship model was studied alone without any appendages. The open water test was also conducted on the ship's propeller. Then, the results were subject to Verification and Validation procedure to demonstrate the accuracy of the equations and turbulence model used.

CFD Study of Influence of the Drift Angles on the Flow Properties Around DARPA Suboff Submarine with the Propeller

2023-09-30T09:33:35+00:00

This research calculates and analyzes the flow around the DARPA Suboff submarine using a Computational Fluid Dynamics (CFD) technique. It was focused on the flow at different sailing conditions (at the straight course and different drift angles), the resistance affecting the submarine during sailing was calculated, as well as the pressure distribution on the hull surface and the velocity distribution in the propeller plane at different situations (DARPA alone, DARPA with fins, DARPA with fins and propeller and DARPA with propeller without fins). The RANS method and k-ω Shear Stress Transport (SST) model with the ANSYS program were used to solve the Navier-Stokes equations. The numerical results were compared with experimental data. This Comparison showed how accurate CFD technology is in calculating this type of flow case.

Effect of Cut-Off Angles on Observational Accuracy in GPS Measurements

2023-11-12T05:01:11+00:00

This scientific study investigates the impact of cut-off angles on the accuracy of measurements obtained using the Global Positioning System (GPS) and evaluates the effect of varying cut-off angles on precision. Data from measurements conducted at five different cut-off angles (0º, 5º, 10º, 15º, 20º) were analyzed. After reviewing the standard deviations (Std Dev) for the North (N), East (E), Up (U), and Horizontal (Hz) components, variable responses to changes in cut-off angles were detected. This study provides a comprehensive analysis of the effects of cut-off angles on GPS measurements. Cut-off angles determine the minimum elevation angle above the horizon at which GPS satellites are considered visible and trackable by the receiver. Understanding the consequences of choosing specific cut-off angles is crucial for enhancing GPS-based applications and research.

In this study, we will focus on testing the effect of cut-off angles on the following aspects:

Satellite Visibility.
Positioning Accuracy.
Signal Strength and Multipath Effects.

Assessing Distance Protection Systems’ Impact on the Dynamic Security of the Power System

2023-09-15T14:19:54+00:00

Electrical power system security and reliability are considered to be the main tasks of transmission system operators (TSOs), but most research on power system security missed the assessment of the impacts of protection systems on system security. Therefore, in this paper, we present an assessment of the influences of the parameters and the functions of distance protection devices in transmission networks (especially the Direct Underreaching Transfer Trip function (DUTT)) upon the dynamic security of the power system.

The effects of distance protection systems were analysed using a set of indices that are determined based on the number of pickups and unwanted operations with the corresponding time instants, as well as the amount of lost load and the time duration in which the impedance trajectory is inside the distance protection zones, throughout taking several contingencies into consideration.

As a result of the assessment, we get a ranking of distance protection devices that is useful to highlight weak points of the protection system, we also get a ranking of contingencies that is useful to determine cascade tripping cases and critical system conditions after the fault. This enables the selection of the optimal algorithms for distance protection relays and thus ensures a more secure operation of the electrical power system.

Exergy analysis study a Jander combined (gas-steam) power plant

2023-03-11T09:03:26+00:00

In this research an analysis of exergy was carried out in a combined (gas-steam) Gander thermal power plant to generate electrical energy at several variable loads ,modeling was done on the EES program (Engineering Equation Solver) ,where the actual data of the power plant's work was entered ,and the rest of the parameters were calculated based on EES ,and the mathematical equations necessary for the exergy analysis of the parts of the thermal cycle were programmed by adopting on exergy equilibrium equations in each component of the power plant , Determining the exergy losses and exergy efficiency in each component ,the exergy was analyzed at variable loads (75%,100%) for each of the air compressor ,combustion chamber ,gas turbine ,(HRSG) heat recovery steam generator ,steam turbine and air cooled condenser.

The effect of several investment factors on the oxygen efficiencies at the station was also studied: ambient temperature ,condenser pressure.

Design and Implementation of a DC Motor Control Platform Using the LabVIEW Programming Environment and the Microcontroller

2023-09-30T09:20:24+00:00

The research deals with the design and implementation of a DC motor control platform intended for educational purposes using the Arduino microcontroller and the LabVIEW software environment. The designed system monitors the working status of the DC motor, measures its parameters (intensity of the current drawn - rotational speed - torque - load ratio) and draws its speed-torque curve, as well as an emergency stop when the nominal values of the current are exceeded. The results of testing the designed system on a parallel induction DC motor with a power of 24W showed that the designed system performs its functions correctly and achieves its desired purpose in terms of:

The possibility of monitoring the values of the parameters of the tested motor in real time and the extent of changes in the values of these parameters when the load on the motor axis increases, as the value of the intensity of the current drawn increases, as well as the value of the torque, while the value of the rotational speed decreases.
Controlling the start and stop of the motor and activating the emergency state when the nominal current value of the tested motor (2A) is exceeded in order to protect against overload.
Plot the speed-torque curve of the tested motor at different load levels.