Articles in This Issue
Abstract
To find the Reduced Level ( R.L.) by traditional methods especially by the precise methods , for example using the level , needs time , hard work and then high cost . By using the new technology like Global Positioning System (GPS) reduces the time , the work and the cost .But the highest accuracy still remains for the traditional methods , and approximately the same accuracy could be reached by using precise surveying receivers of GPS with precise methods .Because there are no surveying receivers ,a navigation receiver (Trimble Geo XT handheld receiver ) is used in this research to get the (R.L.) (height above the Mean Sea Level ( the Fao in Iraq )) in the used system in Iraq (Clarke – 1880) in the area where the measurements are done( the University of Technology ). The (R.L.) of points in any other area in Iraq ,and by any other system in other country could be found in the same method . In this method , the changing factor from the measured heights (HAE) on the World Geodetic System (WGS – 1984 ) in any determined area by using the above receiver to heights on ( Clarke – 1880) in the same area can be found . When the changing factor of any area is found, the measured height of any point in this area (HAE) by using a receiver of (GPS) could be changed to the height in (Clarke – 1880 ). Then the (R.L.) of this point could be calculated by adding the Separation or the Geoidal Height between the Ellipsoid and the Geoid for the point , and the reverse is possible also.
Abstract
AbstractPresented in this paper is a variational solution of the two-endpoint boundary value problem of route location in cost heterogeneous terrain. The terrain consists of two cost subregions separated by a single straight cost boundary line. The integral concerning the total transportation cost is minimized to obtain the optimum route. The analytical solution developed on the basis of calculus of variations was applied to different cases of cost ratios using a computer program, which was written in MCAD language. A comparison is made between the developed analytical solution based on variational technique with that based on Snell’s law of light refraction and excellent agreement was obtained.
Abstract
This paper presents a detailed explanation about the types of control charts or statistical adjustment, their importance, the qualities of their usage and the method of how to work with them. Besides, it presents the types, characteristics, and usage of the concrete blocks as a theoretical side of the paper. As an applied side of the paper, it introduces the method of using the control charts in determining the suitable decisions about the production process of manufacturing concrete blocks, and how it would help to show the actual variation in the produced units. Identification of defected units in an early stage of production will save materials and production costs.
Abstract
AbstractA full three dimensional finite element computational model is constructed for nonlinear analysis of reinforced concrete curved beams. This model was presented utilizing computer program ANSYS (Version 11), which is capable of an efficient analysis of the response at different load levels including ultimate loads.This work deals with the structural analysis of concrete curved beams behaviour subjected to two concentrated loads. Concrete curved beams are widely used in building and bridge constructions. Some of the available experimental tests on reinforced concrete curved beams are theoretically analyzed. This covers load-deflection relationships, crack pattern and propagation of crack at different stages of load and ultimate load capacity. The reliability of the model is demonstrated by comparison with available experimental results and alternative numerical analyses which shows 4 – 8 % difference.
Abstract
In this research the finite element method is used to analyses the effect of groynes on the coefficient of Manning's value in meandering sandy channels is used. A two dimensional model of quadrilateral isoperimetric element is used, two meandering sandy channels were analyzed. The first channel has a central angle of ( 40o) with radius of curvature of (1.7m) , while the second channel has a central angle of ( 60o) with a radius of curvature of (2m) with a trapezoidal cross – section having a lower base of(1m) and side slope of ( 2H : 1V) and with bed slope of channels of ( 0.15% ). The main diameter of the sand used in this research of channels of (0.9mm ) achieved using observed data of Euphrates river at regulator of falluja. Five sections were located on each channels and four different discharges were passed through the two channels, the groynes sloped towards upstream were used in different locations at upstream and down stream of channels.
Abstract
AbstractDeflection of partially prestressed concrete beams is investigated using the finite element method taking in to account the plasticity of steel, nonlinearity of concrete in compression and tension softening of concrete. Embedded bar approach is used to represent the steel reinforcement and prestressing tendon in concrete layer. Elastic perfectly-plastic approach has been employed to model the compressive behaviour of the concrete.The yield condition is formulated in terms of the first two-stress invariants. The movement of the subsequent loading surfaces is controlled by the hardening rule, which is extrapolated from the uniaxial stress-strain relationship defined by a parabolic function. Concrete crushing is a strain controlled phenomenon, and can be monitored by a fracture surface similar to the yield surface. A smeared fixed crack approach is used to model the behaviour of the cracked concrete, with a tensile strength criterion to predict crack initiation. The steel is considered as an elastic perfectly plastic material with linear strain hardening, steel reinforcement is assumed to have similar tensile and compressive stress-strain relationship. The calculated and the observed effects have shown a satisfactory agreement compared with experimental results.
Abstract
The first step toward urban transportation planning is to make a data base then to initiate the first mathematical model known as trip generation model which this study adopts. The study area in the waste sector of Ramadi city (Al-Tameem, 5 km) is considered as one sector consists of eight zones containing about 11640 dwelling units. Home interview survey was made of random sample which represent 5% of the study area population. The collected information was concerned with structure, vehicles, families and each person living in the dwelling unit. The total person’s trips per dwelling unit and various purposes were investigated. All data was programmed for analysis by spss program, which took place firstly by multiple linear regression to obtain the primarily models. After series of analysis and trials, the most significant independent variables were identified as family size and car ownership. Also, the final equations for producing trips were obtained. They were reasonable, more practical and carrying the best statistical measures. Set of curves were developed to put the sub models in any easy and more desirable manner for wide application and forecasting.