The multi-storey steel building widely used due to its light gravity loads that is very useful for regions of low soil bearing capacity. Also easy of manufacturing and erecting make it a right choice comparing with other structures. In the last years, the Halabja earthquake may classifieds as the largest base excitation that causes a rapid change in the Iraqi seismic map. Therefore, the aim of the study is to investigate the steel building behaviour under Halabja earthquake loading using a non-linear time history analysis and comparing the results with those obtained from linear static analysis depending to the ISC 1997 and the modern seismic standard ISC 2017. A non-linear analysis using a time history approach was carried out for varied steel multi-storey building models. These models were analysed and designed under dead, live, wind and seismic loads using Staad Pro V8i Software. Results shows that the Iraqi Seismic Code (ISC) 2017 is a good approach to predicting the base shear and the story drift comparing with time history analysis under Halabja earthquake loading, while the Iraqi Seismic Code (ISC) 1997 seems to be very conservative approach.
An experimental model is used to simulate the loss of soil lateral confinement due to excavation nearby an individual axially loaded pile. The effects of various parameters, such as the horizontal distance of excavation, depth of excavation and pile slenderness ratios are investigated. The experimental analysis results showed the effect of excavation is more remarkable as the horizontal distance of excavation becomes closer to the pile than half pile length. The effect of excavation diminishes gradually as the horizontal distance increases beyond that distance for all the investigated pile slenderness ratios and depths of excavation. The pile head deflection, settlement and bending moments along pile increase with decreasing horizontal distance between excavation face and adjacent axially loaded pile of various depths of excavation and pile slenderness ratios. The location of maximum bending moment is positioned between 1/4 and 1/2 of pile length for all horizontal distance of excavation, depth of excavation and slenderness ratios. The bending moment profiles indicate a (single curvature) for medium flexible piles and (double curvature) for very flexible piles for different horizontal distance between excavation face and adjacent axially loaded pile and various depths of excavation. In addition the theoretical approach of wood, 2004 showed good agreement especially for very flexible pile (slenderness ratio ˃45).
Various regions of the world experience oil pollution for many reasons, including oil spills due to transport accidents or during oil exploration. These oil spills will have a negative impact on the environment and can change the geotechnical properties of the soil. The soil in Faw city, in the southeast of Basra Governorate, is frequently polluted due to the presence of many pipes and wells; oil leakage has been encountered as a result of damage to these pipes. The aim of this article is to study the effects of black oil on the physical and engineering characteristics of Faw soil. The analyses include two parts: (a) Natural soil properties and (b) Contaminated soil properties with oil percentages of 2.0, 5.0, 10.0, 15.0, and 20.0 % of the weight of the dry samples. Various tests were carried out. The results show an increase in soil compressibility and reduction in permeability due to the addition of black oil. In addition, the results show that using a layer of soil-oil-water under the foundation is advisable. This layer must be isolated from living creatures.
Soil movement resulting due unsupported excavation nearby axially loaded piles imposes significant structural troubles on geotechnical engineers especially for piles that are not designed to account for loss of lateral confinement. In this study the field excavation works of 7.0 m deep open tunnel was continuously followed up by the authors. The work is related to the project of developing the Army canal in the east of Baghdad city in Iraq. A number of selected points around the field excavation are installed on the ground surface at different horizontal distance. The elevation and coordinates of points are recorded during 23 days with excavation progress period. The field excavation process was numerically simulated by using the finite element package PLAXIS 3D foundation. The obtained analysis results regarding the displacements of the selected points are compared with the field observation for verification purpose. Moreover, finite element analysis of axially loaded piles that are presumed to be existed at the locations of the observation points is carried out to study the effect of excavation on full scale piles behaviors. The field observation monitored an upward movement and positive lateral ground movement for shallow excavation depth. Later on and as the excavation process went deeper, a downward movement and negative lateral ground movement are noticed. The analyses results are in general well agreed with the monitored values of soil displacements at the selected points. It is found also that there are obvious effects of the nearby excavation on the presumed piles in terms of displacements and bending moments.
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