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1.
Ahmad Shlash Alawneh Osama K. Nusier Ahmed Abdul-Ezel Al-Mufty 《Geotechnical and Geological Engineering》2006,24(3):637-660
A reliability based method was used to design and analyse shallow foundations using first-order Taylor series approximation.
The computer program Mathcad was used to facilitate all mathematical and computional efforts. This method is an effective
tool to assist the foundation designers and analyists to investigate how reliable their designs or analyses are in relation
to the ultimate bearing capacity of the foundations. The approach presented in this paper provides a reliable alternative
for design and analysis of shallow foundations, rather than the conventional design methods, which employs the assumptions
of a specified saftey factor. Several examples were presented for design and analysis of strip footings embedded in sandy
soil, and rectangular and square footings analysis embedded in clayey soils. The program input and output of each example
are also presented and discussed. 相似文献
2.
Syenogranitic dykes in the north of Egypt’s Eastern Desert are of geological and economic interest because of the presence of magmatic and supergene enrichment of radioactive mineralization. Zircon crystal morphology within the syenogranitic dykes allows precise definition of sub-alkaline series granites and crystallized at mean temperature of about 637 °C. The growth pattern of the zircons suggest magmatic and hydrothermal origins of radioactive mineralization. Hydrothermal processes are responsible for the formation of significant zircon overgrowth; high U-zircon margins might have occurred contemporaneously with the emplacement of syenogranitic dykes which show anomalous uranium (eU) and thorium (eTh) contents of up to 1386 and 7330 ppm, respectively. Zircon chemistry revealed a relative increase of Hf consistent with decreasing Zr content, suggesting the replacement of Zr by Hf during hydrothermal activity. Visible uranium mineralization is present and recognized by the presence of uranophane and autunite. 相似文献
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Mohamed Sabri Arfaoui Radhouane Khouni Soufiene Dridi Fouad Zargouni 《Arabian Journal of Geosciences》2018,11(5):95
The Bou Arada-El Fahs troughs system is a particularly E-W trending collapsed structure with the manifestation of normal-to-strike-slip faults. A combined multi-source and multi-scalar structural and geophysical investigation provides important insights on the geometry and the kinematics evolution of trough systems in the Atlas of Tunisia. New data, as well as a reappraisal of available data show that the studied troughs system is established during three main successive events: the Oligocene-Miocene, the Tortonian, and the Plio-Quaternary events. The goal of this paper is to present the structural evolution of the study area, on a pre-structured substratum. The structural evolution progressed from an extensional event, manifested by the formation of grabens, passing by an episode of reactivation of faults related troughs in strike-slip motion during the Atlas compression accompanied by an en-échelon folding in foot wall and hanging wall. These results acquired and presented in the following order: We will initially present the geological context by integrating and correlating the lithostratigraphic data. We continue by examining the geometry and kinematics of structure-related troughs via the detailed geological mapping, the interpretation of available 2D seismic data, and the interpretation of processed fault slip data. This integrated geological and geophysical study allows a better understanding of the BETS, and makes it possible to propose a new geometrical and kinetic model of the establishment of trough structure in the Tunisian Atlas. 相似文献
5.
A thermal ionisation mass spectrometric technique enabled the abundance of Zn in geological and biological reference materials and water samples to be measured by double spiking isotope dilution mass spectrometry enriched in the 67Zn and 70Zn isotopes. In the past, thermal ionisation mass spectrometry proved to be difficult for low-level zinc isotopic measurements. The size of Zn samples used for isotopic determination, in particular the biological RMs, represents an important breakthrough. These results represent the most accurate and precise concentrations measured for Zn in these samples. The maximum fractional uncertainty was that for TILL-3 (2%), while the minimum fractional uncertainty was 0.7% for both BCR-1 and W-2. The inhomogeneity of Zn in HISS-1 was revealed while other reference materials appeared homogeneous at the 95% confidence uncertainty. The certified concentration of Zn in HISS-1 and IMEP-19 by their producers are 28% and 3.8% higher than the values measured in this work. These are the first Zn concentration measurements in these materials by the isotope dilution-TIMS technique, except for BCR-1, NIES No 9 and IMEP-19. Reducing the blank enabled accurate measurement in water at the ng g-1 level demonstrating the applicability of the technique for low-level Zn samples. 相似文献
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Characteristics of concentrated flow hydraulics for rangeland ecosystems: implications for hydrologic modeling 总被引：1，自引：0，他引：1
Osama Z. Al‐Hamdan F.B. Pierson Jr M.A. Nearing J.J. Stone C.J. Williams C.A. Moffet P.R. Kormos J. Boll M.A. Weltz 《地球表面变化过程与地形》2012,37(2):157-168
Concentrated flow is often the dominant source of water erosion following disturbance on rangelands. Because of the lack of studies that explain the hydraulics of concentrated flow on rangelands, cropland‐based equations have typically been used for rangeland hydrology and erosion modeling, leading to less accurate predictions due to different soil and vegetation cover characteristics. This study investigates the hydraulics of concentrated flow using unconfined field experimental data over diverse rangeland landscapes within the Great Basin Region, United States. The results imply that the overall hydraulics of concentrated flow on rangelands differ significantly from those of cropland rills. Concentrated flow hydraulics on rangelands are largely controlled by the amount of cover or bare soil and hillslope angle. New predictive equations for concentrated flow velocity (R2 = 0·47), hydraulic friction (R2 = 0·52), and width (R2 = 0·4) representing a diverse set of rangeland environments were developed. The resulting equations are applicable across a wide span of ecological sites, soils, slopes, and vegetation and ground cover conditions and can be used by physically‐based rangeland hydrology and erosion models to estimate rangeland concentrated flow hydraulic parameters. Published in 2011. This article is a US Government work and is in the public domain in the USA. 相似文献
8.
A detailed geophysical investigation in the form of electrical resistivity tomography (ERT) was carried out using the SYSCAL Pro Unit at two locations with a dipole?Cdipole configuration in one of the private farms in Diriyah area of Riyadh, Saudi Arabia with the purpose of delineating the approximate depth of the water-bearing formations. The survey helped in delineating a superficial moist zone at the first site which was mainly due to the seepage from surface water pipes used for irrigating the date palms. At the second site, a potential water-bearing zone was detected starting from a depth of 23 to 46?m. However, an already existing bore well in close vicinity of the site of the second survey showed a water table depth of 85?m, indicating the presence of a layered aquifer. Finally, it was concluded that a shallow bore well drilled up to a depth of 50?C60?meters would be able to tap the water resources of shallow water-bearing horizon discovered at the second site during the survey; however, the yield of the bore well might not be sustainable over a longer period of time. The survey at the first site did not show any promising groundwater potential up to the investigated depth which was around 70?m. The study confirms the usage of ERT surveys for exploring sources of freshwater supplies in arid regions. 相似文献
9.
Gravity and magnetotelluric investigations to elicit the origin of Hammam Faraun hot spring,Sinai Peninsula,Egypt 总被引：1，自引：0，他引：1
Mohamed Abdelzaher Jun Nishijima Gad El-Qady Essam Aboud Osama Masoud Mamdoh Soliman Sachio Ehara 《Acta Geophysica》2011,59(3):633-656
There is a clear correlation between the principal areas of current geothermal development and the seismically active boundaries
of the moving segments of lithosphere defined by the plate tectonic models of the Earth. The tectonic position of Egypt in
the northeastern corner of African continent suggests that the most important areas for geothermal exploration are in the
region where a cluster of hot springs with varied temperatures was located around the Gulf of Suez. Gravity and magnetotelluric
surveys were made in the area of Hammam Faraun hot spring, which represents the most promising area for geothermal development
in Egypt. These surveys were carried out for the purpose of eliciting the origin of Hammam Faraun hot spring. The results
of the analyses and interpretations of these data show that the heat source of the hot spring is due to uplift of hot basement
rock. This uplift may cause deep circulation and heating of the undergroundwater. 相似文献
10.
Osama M. K. Kassem 《Geotectonics》2011,45(3):244-254
Finite-strain was studied in the mylonitic granitic and metasedimentary rocks in the northern thrust in Wadi Mubarak belt
to show a relationship to nappe contacts between the old granitic and metavolcano-sedimentary rocks and to shed light on the
heterogeneous deformation for the northern thrust in Wadi Mubarak belt. We used the Rf/ϕ and Fry methods on feldspar porphyroclasts, quartz and mafic grains from 7 old granitic and 7 metasedimentary samples in
the northern thrust in Wadi Mubarak belt. The finite-strain data shows that old granitic rocks were moderate to highly deformed
and axial ratios in the XZ section range from 3.05 to 7.10 for granitic and metasedimentary rocks. The long axes (X) of the
finite-strain ellipsoids trend W/WNW and E/ENE in the northern thrust in Wadi Mubarak belt. Furthermore, the short axes (Z)
are subvertical associated with a subhorizontal foliation. The value of strain magnitudes mainly constants towards the tectonic
contacts between the mylonitic granite and metavolcano-sedimentary rocks. The data indicate oblate strain symmetry (flattening
strain) in the mylonitic granite rocks. It is suggested that the accumulation of finite strain was formed before or/and during
nappe contacts. The penetrative subhorizontal foliation is subparallel to the tectonic contacts with the overlying nappes
and foliation was formed during nappe thrusting. 相似文献