ABSTRACT The effect of using different protection devices on water hammer phenomenon to provide an acceptable level of protection against system failure due to pipe collapse or bursting is presented. Water Hammer and Mass Oscillation (WHAMO) software is used in the analysis which uses the implicit finite difference scheme for solving the momentum and continuity equations at unsteady state case. Assiut city water supply network is used. The network is supplied from two points at pump No. 36 and pump No. 37. Flow of pipe network is studied under steady normal case, without any protection case against water hammer phenomenon, and the model under different operation cases; with a transient protection device(s) such as non-return valve, open surge tank, air chamber and pressure relief valve (PRV). The results are performed for three scenarios; the first is the normal operation of pump 36 and failure of pump 37, the second is the normal operation of pump 37 and failure of pump 36, and finally failure of pumps 36 and 37 together. The results showed that using of open surge tank or air chamber with non-return valve protects the pipe network effectively from the harm of water hammer. Also, using PRV with non-return valve protects the pipe network from extreme pressures. Although using non-return valve only doesn’t have a great effect on the maximum pressure head than the normal case, it protects the network from the more low pressures than without protection one. All protection cases safeguard the pipe network from the extremes of water hammer, but increase the water hammer wave period. Finally, the sudden shut down of the pumps 36 and 37 together has the large effect on the pressure heads than the shut down of any of them only.

ABSTRACT The effect of using different protection devices on water hammer phenomenon to provide an acceptable level of protection against system failure due to pipe collapse or bursting is presented. Water Hammer and Mass Oscillation (WHAMO) software is used in the analysis which uses the implicit finite difference scheme for solving the momentum and continuity equations at unsteady state case. Assiut city water supply network is used. The network is supplied from two points at pump No. 36 and pump No. 37. Flow of pipe network is studied under steady normal case, without any protection case against water hammer phenomenon, and the model under different operation cases; with a transient protection device(s) such as non-return valve, open surge tank, air chamber and pressure relief valve (PRV). The results are performed for three scenarios; the first is the normal operation of pump 36 and failure of pump 37, the second is the normal operation of pump 37 and failure of pump 36, and finally failure of pumps 36 and 37 together. The results showed that using of open surge tank or air chamber with non-return valve protects the pipe network effectively from the harm of water hammer. Also, using PRV with non-return valve protects the pipe network from extreme pressures. Although using non-return valve only doesn’t have a great effect on the maximum pressure head than the normal case, it protects the network from the more low pressures than without protection one. All protection cases safeguard the pipe network from the extremes of water hammer, but increase the water hammer wave period. Finally, the sudden shut down of the pumps 36 and 37 together has the large effect on the pressure heads than the shut down of any of them only.

In geotechnical investigation, determination oftheseismic bearing capacity of foundation soil constitutes an important task. The bearing capacity of soil under static loading has been extensively studied since the early work of Prandtl (1921).Design of foundation in seismic areas needs special considerations compared to the static case. The inadequate performance of structure during recent earthquake has motivated researches to revise existing methods and to develop new method for seismic resistant design. For foundation of structure built in seismic areas the demands to sustain load and deformation during earthquake will probably be the severe in their design life. Due to seismic loading foundation may experience decreases in bearing capacity and increases in settlement. Two source of loading must be taken into consideration inertial loading caused by lateral forces imposed on the superstructure, kinematic loading caused by the ground movement developed during earthquake.

In geotechnical investigation, determination of the bearing capacity of foundation soil constitutes is an important task. Most of the previous studies investigated the stability of such foundation system using classical bearing theory. The classical bearing theory was developed depending on the theory of plasticity with the assumption that the soil behaves as a rigid-plastic material. The bearing capacity theories require making a guess on the shape and geometry of the most critical failure surface (mechanism of failure) a priori. Most theories assumed the geometry of the failing soil mass is symmetrical with respect to the center of the footing, while, Krey suggested that the geometry of the failing mass is unsymmetrical. Numerical methods do not require an initial assumption the geometry of the failure mode. In the present work, a numerical study assisted by a computer program is carried out using (Krey’s method) to investigate the center of the slip circle gives the minimum bearing capacity of the footing. Also, PLAXIS 2D used for analysis of some cases of studies by Krey’s method. Krey it's of the present study is compared with the classical theories of the ultimate bearing capacity. The predicted values of ultimate bearing capacity of soil of this study are less than those of others theories of ultimate bearing capacity. In order to facilitate the calculation of bearing capacity the proposed equations are used. It is a function of (footing width, (B), ratio of footing depth to its width, (Rf) , angle of internal friction of soil, (

Time history analysis was performed to study the effect of selected parameters in the behaviour of reinforced concrete frames under earthquake loads. The RC frames were designed for gravity-loads only as typically found in most seismic prone countries before the introduction of adequate seismic design code provisions. The parameters considered in this study were the number and span of bays, the number of stories, and the presence of infill wall (full infilled frame and infilled frame with open ground stories). It was observed that the presence of infill wall may affect the seismic behaviour of frame structure to large extent, and the infill wall increases the strength and stiffness of the structure. Also it was observed that infilled frames are preferred in seismic regions than the open ground story ones, because the story drift of first story in open ground story frames is very large than the upper stories, this may probably cause the collapse of structure.

Time history analysis was performed to study the effect of selected parameters in the behaviour of reinforced concrete frames under earthquake loads. The RC frames were designed for gravity-loads only as typically found in most seismic prone countries before the introduction of adequate seismic design code provisions. The parameters considered in this study were the number and span of bays, the number of stories, and the presence of infill wall (full infilled frame and infilled frame with open ground stories). It was observed that the presence of infill wall may affect the seismic behaviour of frame structure to large extent, and the infill wall increases the strength and stiffness of the structure. Also it was observed that infilled frames are preferred in seismic regions than the open ground story ones, because the story drift of first story in open ground story frames is very large than the upper stories, this may probably cause the collapse of structure.

The lateral swelling of expansive soil on retaining structures investigation is very important for civil engineer .The used soil in this research is obtained from Assiut el gadida city projects; Assiut, Egypt .It contains SiO2, AL2O3 and Fe2O3 as main oxides. For this research the physical and mechanical properties of soil are obtained, the purpose of the present paper is examining the phenomenon of lateral swelling pressure developed in clay soils after adding water to it. Also suggest useful means to predict the magnitude and distribution of those pressures for use in retaining structure design. The behaviour of soil is swelling after adding water then affects on retaining structure. The effect of soil is depending on many factors as water content, depth, the type and quantity of mineral in soil composition, the time… etc. The results showed that the swelling pressure on retaining structure increases by increasing the depth at soil up to depth equals 60cm and decreases beyond that. Also, the maximum swelling pressure occurred after 48 hours measured from adding water to expansive soil.

The lateral swelling of expansive soil on retaining structures investigation is very important for civil engineer .The used soil in this research is obtained from Assiut el gadida city projects; Assiut, Egypt .It contains SiO2, AL2O3 and Fe2O3 as main oxides. For this research the physical and mechanical properties of soil are obtained, the purpose of the present paper is examining the phenomenon of lateral swelling pressure developed in clay soils after adding water to it. Also suggest useful means to predict the magnitude and distribution of those pressures for use in retaining structure design. The behaviour of soil is swelling after adding water then affects on retaining structure. The effect of soil is depending on many factors as water content, depth, the type and quantity of mineral in soil composition, the time… etc. The results showed that the swelling pressure on retaining structure increases by increasing the depth at soil up to depth equals 60cm and decreases beyond that. Also, the maximum swelling pressure occurred after 48 hours measured from adding water to expansive soil.

This experimental study investigates the influence of replacing certain ratios of natural aggregate by recycled concrete aggregate on properties of fresh and hardened concrete. Two maximum nominal sizes of aggregate used in this study 40 mm and 20 mm, the source of used recycled concrete aggregate comes from the demolitions of the upper skeleton of Al-AZHAR building in Sohag. Thirty six mixes were designed and carried out to study the effect of both aggregate size and replacement ratios on concrete properties, the replacement ratio of recycled aggregate changed from 0 to 50% using of two sizes of aggregate 20 and 40 mm. A slump and compacting factor were measured to express fresh concrete properties, hardened concrete properties were expressed by compressive strength tests after 7 and 28 days, pull out bond strength, splitting tensile strength and flexure strength. Test results shows the bad effect of replacing natural aggregate by recycled concrete aggregate on both fresh and hardened concrete properties.

This experimental study investigates the influence of replacing certain ratios of natural aggregate by recycled concrete aggregate on properties of fresh and hardened concrete. Two maximum nominal sizes of aggregate used in this study 40 mm and 20 mm, the source of used recycled concrete aggregate comes from the demolitions of the upper skeleton of Al-AZHAR building in Sohag. Thirty six mixes were designed and carried out to study the effect of both aggregate size and replacement ratios on concrete properties, the replacement ratio of recycled aggregate changed from 0 to 50% using of two sizes of aggregate 20 and 40 mm. A slump and compacting factor were measured to express fresh concrete properties, hardened concrete properties were expressed by compressive strength tests after 7 and 28 days, pull out bond strength, splitting tensile strength and flexure strength. Test results shows the bad effect of replacing natural aggregate by recycled concrete aggregate on both fresh and hardened concrete properties.