Abstract The new trend of development in Libya is building a more high rise buildings (tall buildings) in dense populated cities like Tripoli to limit the horizontal expansion of the cities.Therefore, an accurate estimation of wind load is an important factor for the design of such tall buildings.This research examines the effects of wind on the design of buildings, and explaining wind types dominating territory. The thesis main focus is analysing the wind data collected from 22 meteorological stations distributed around the country.The wind data analysis is carried out by using a probability distribution model that created an estimation of the design wind speed with a return period of 50 – year for each city’s station.The established wind speed is then used to create a design wind speed contour map for the entire country using special software.
محمد بشير أبوهدامة (2009)

Abstract Behavior of constant thickness circular plates under axisymmetric uniform loading and for different edge boundary conditions may be obtained analytically, but for the case of variable thickness and transverse shear effect is usually difficult to follow analytically. Since the numerical analysis has become an essential tool in engineering mechanics, where the use of numerical methods enables the engineer to expand his or her ability to solve practical design problems, where the engineer may now treat real shapes as distinct from the somewhat limited variety of shapes amenable to simple analytic solution. That is why developing an appropriate numerical analysis becomes a more suited procedure to solve such problems. The standard stiffness procedure of finite element method may encounter some difficulty in formulation when dealing with both cases of variable thickness and transverse shear effect. The usually followed procedure is to utilize ring elements of constant thickness and increase the number of elements to reach an accurate solution. Mixed finite element formulation utilizing curved ring element with linearly varying thickness as well as considering the shear effect has proved to be successful to obtain accurate results for shells of revolution with small number of elements, due to the fact that the mixed formulation allows for nodal values in the form of global displacement components (ur, uz) and bending moment (Mr, M) as field variables, where second order polynomials may be used allowing for shear deformation effect to be considered as a function of moments and does not require higher order polynomials.
ايناس عبدالمولي المصراتي (2009)

Estimating the service life of Reinforced Concrete (RC) bridge structures located in corrosive marine environments of a great importance to their owners/engineers. Traditionally, bridge owners/engineers relied more on subjective engineering judgment, e.g. visual inspection, in their estimation approach. However, because financial resources are often limited, rational calculation methods of estimation are needed to aid in making reliable and more accurate predictions of the service life of RC structures. This is in order to direct funds to bridges found to be the most critical. Criticality of the structure can be considered either from the Structural Capacity (i.e. Ultimate Limit State) or from Serviceability viewpoint whichever is adopted. This paper considers the service life of the structure only from the Structural Capacity viewpoint. Considering the great variability associated with the parameters involved in the estimation process, the probabilistic approach is most suited. The probabilistic modelling adopted here used Monte Carlo simulation technique to estimate the Reliability (i.e. Probability of Failure) of the structure under consideration. In this paper the authors used their own experimental data for the Correlation Length (CL) for the most important deterioration parameters. The CL is a parameter of the Correlation Function (CF) by which the spatial fluctuation of a certain deterioration parameter is described. The CL data used here were produced by analyzing 45 chloride profiles obtained from a 30 years old RC bridge located in a marine environment. The service life of the structure was predicted in terms of the load carrying capacity of an RC bridge beam girder. The analysis showed that the influence of SV is only evident if the reliability of the structure is governed by the Flexure failure rather than by the Shear failure. arabic 14 English 80
Omran Mohamed Saleh Kenshel(2-2021)