Foundation is considered as one of the main parts of any structure. The type of foundation used is highly dependent on the type and properties of soil. The design of foundations requires many factors that should be de...Foundation is considered as one of the main parts of any structure. The type of foundation used is highly dependent on the type and properties of soil. The design of foundations requires many factors that should be defined. There are number of differences in the geological and soil conditions in Iraq. As a consequence, these differences are reflected on the type of foundation to be used. Despite these differences, same materials and style of buildings are used all over Iraq. The main problems of Iraqi soil are high gypsum content, salinity and shallow water table depth. These factors that influence the foundations are the soil properties and the amount of loads that transmitted by the superstructure. The situation has been analysed through a case study which illustrated the link between soil and foundation types in three different parts of Iraq （Mosul, Baghdad and Basra）. One building was analysed using ＂STAAD （structural analysis and design）. Pro＂ software in these regions. It is evident that Iraqi designers and engineers require local code to define all the loads, materials and design of the foundation to be used. The use of local materials might be very effective from both engineering and economic perspectives.展开更多
Free vibration analysis of non-homogeneous orthotropic plates resting on a Pasternak type of elastic foundation is investigated. A set of admissible orthogonal polynomials are generated with Gram-Schmidt orthogonaliza...Free vibration analysis of non-homogeneous orthotropic plates resting on a Pasternak type of elastic foundation is investigated. A set of admissible orthogonal polynomials are generated with Gram-Schmidt orthogonalization procedure and adopted in the Rayleigh-Ritz method. Accuracy and applicability of the method are examined by comparison of the results for different boundary conditions and material types with those available in literature. It is found that this method has good accuracy regardless of type of boundary condition and yields very accurate results even with low number of terms of orthogonal polynomials for the first mode of vibration. For higher modes of vibration, higher terms of orthogonal polynomials should be used. The effects of foundation parameter, density and non-homogeneity parameters on natural frequency are examined. It is concluded that natural frequency of plates are more sensitive to shearing layer coefficient rather than Winkler coefficient and density parameter has weakening effect on natural frequency.展开更多
文摘Foundation is considered as one of the main parts of any structure. The type of foundation used is highly dependent on the type and properties of soil. The design of foundations requires many factors that should be defined. There are number of differences in the geological and soil conditions in Iraq. As a consequence, these differences are reflected on the type of foundation to be used. Despite these differences, same materials and style of buildings are used all over Iraq. The main problems of Iraqi soil are high gypsum content, salinity and shallow water table depth. These factors that influence the foundations are the soil properties and the amount of loads that transmitted by the superstructure. The situation has been analysed through a case study which illustrated the link between soil and foundation types in three different parts of Iraq （Mosul, Baghdad and Basra）. One building was analysed using ＂STAAD （structural analysis and design）. Pro＂ software in these regions. It is evident that Iraqi designers and engineers require local code to define all the loads, materials and design of the foundation to be used. The use of local materials might be very effective from both engineering and economic perspectives.
文摘Free vibration analysis of non-homogeneous orthotropic plates resting on a Pasternak type of elastic foundation is investigated. A set of admissible orthogonal polynomials are generated with Gram-Schmidt orthogonalization procedure and adopted in the Rayleigh-Ritz method. Accuracy and applicability of the method are examined by comparison of the results for different boundary conditions and material types with those available in literature. It is found that this method has good accuracy regardless of type of boundary condition and yields very accurate results even with low number of terms of orthogonal polynomials for the first mode of vibration. For higher modes of vibration, higher terms of orthogonal polynomials should be used. The effects of foundation parameter, density and non-homogeneity parameters on natural frequency are examined. It is concluded that natural frequency of plates are more sensitive to shearing layer coefficient rather than Winkler coefficient and density parameter has weakening effect on natural frequency.
