Life-cycle cost and sustainability analysis of light-frame wood residential communities exposed to tornados     

Adhikari  Pramodit  Mahmoud  Hussam N.  Ellingwood  Bruce R. 《Natural Hazards》2021,109(1):523-544

Natural Hazards - Tornadoes pose a significant threat to residential communities, causing enormous physical damage and losses to their social fabric. The dominant type of single-family residential...  相似文献   

Constraints on unconsolidated pyroclastic flow sediments related REE enrichments originated from potassic-alkaline Gölcük stratovolcano: Darıdere-Direkli-Yakaören (DDY) table 4deposits,southwestern Anatolia of Turkey     

Budakoglu  Murat  Unluer  Ali Tugcan  Doner  Zeynep  Kocaturk  Huseyin  Kaya  Mustafa  Kumral  Mustafa  Kirikoglu  M. Sezai 《中国地球化学学报》2021,40(6):926-944

Acta Geochimica - In the last five decades, Rare Earth Elements (REE) are mostly produced from carbonatite complexes and alkaline magmatic environments. In this respect, pyroclastic flows produced...  相似文献   

Erratum to: Seismic intensity zoning and earthquake risk mapping in Iraq     

Khalid J. Fahmi 《Natural Hazards》1989,2(2):199-199

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Desertification,famine, and the 1988 rainfall —     

Prof. Dr. Mustafa M. Khogali 《GeoJournal》1991,25(1):81-89

The 1988 good rainy season in the Sudan raised the hopes that desertification/land degradation and shortage of food so markedly observed in Western Sudan have been elevated. This was particularly so as large quantities of grains were produced in the mechanized rain-fed agricultural schemes in the clay plains of Eastern Sudan. But the field work carried by the author in the Umm Ruwaba district of Kordofan region in July/August 1989 shows that, although there has been some improvement in the crop production situation, desertification/land degradation and shortage of food produced locally are still prevailing in the district. The people are still living below the poverty line, but they are able to cope because of remittances from members of the families working abroad and because of donations of food by some world organizations.  相似文献   

Present state of geodynamic properties of Kalabsha area, nortwest of Aswan Lake, Egypt     

P. Vysko il  A. Tealeb  R.M. Kebeasy  S.M. Mahmoud 《Journal of Geodynamics》1991,14(1-4)

Aswan Lake is the second largest man-made lake in the world. Its filling started 1964 and reached the maximum water level in 1978. An earthquake of magnitude 5.5 took place in 1981 along the most active fault near the lake (Kalabsha fault). This earthquake was follwed by a tremendous number of smaller events that continue till now.Seismicity and the underground water table around the lake are monitored continuously through a radio-telemetered network. A local geodetic network was established around parts of the active faults in the northwestern part of the High Dam Lake, for monitoring vertical and lateral movements. The Kalabsha local geodetic network (the first one) was established around an active part of the Kalabsha fault in 1983. Precise geodetic measurements have benn carried out twice a year since 1984.On the basis of the repeated geodetic measurements, seismicity of the area and geophysical as well as geological data, the present state of the geodynamical properties of the Kalabsha area is studied.Remarkable horizontal movements were detected; they are correlated with the seismicity of the area and are attributed to the differential loading by the lake. The Kalabsha fault is a right-lateral strike-slip motion on an E-W plane. The magnitude of the movements detected along the fault is variable for the different epochs of measurements and is correlated with both seismicity and water loading in the lake.  相似文献   

A conjugate strike-slip fault system within the extensional tectonics of Western Turkey     

Mustafa Aktar  Hayrullah Karabulut  Serdar Özalaybey  Dean Childs 《Geophysical Journal International》2007,171(3):1363-1375

Three main shocks M-1, M-2 and M-3 (17 October 2005 at 05:45 UTC, M _w 5.4; 17 October at 09:46 UTC, M _w 5.8 and 20 October at 21:40 UTC, M _w 5.9) and their associated aftershocks within the Gulf of S i ğac i k, 50 km southwest of Izmir, Turkey were studied in detail. A temporary seismic network deployed during the activity allowed the hypocentre of M-3 and subsequent aftershocks to be determined with high accuracy. A relative relocation technique was used to improve the epicentres of M-1 and M-2. All three main shocks have strike-slip mechanisms which agree with the linear trends of the aftershock locations. Two distinct zones were illuminated by the aftershock locations. The zones contain clear echelon patterns with slightly different orientations from the trend of the aftershock distribution. M-2 and M-3 ruptured along of the eastern rupture zone which aligns N45°E. However the strike direction of M-1 is not clearly identified. The alignment of the two rupture zones intersect at their southern terminus at an angle of 90°. The fault zones form conjugate pair system and static triggering is considered as a probable mechanism for the sequential west to east occurrence of M-1, M-2 and M-3. This earthquake sequence provides seismological evidence for conjugate strike-slip faulting co-existing within a region dominated by north–south extension and well-developed east–west trending normal faults.  相似文献   

Graben width controlling syn-rift sedimentation: the Palaeogene southern Upper Rhine Graben as an example     

Sebastian Hinsken  Kamil Ustaszewski  Andreas Wetzel 《International Journal of Earth Sciences》2007,96(6):979-1002

Eocene to Early Oligocene syn-rift deposits of the southern Upper Rhine Graben (URG) accumulated in restricted environments. Sedimentation was controlled by local clastic supply from the graben flanks, as well as by strong intra-basinal variations in accommodation space due to differential tectonic subsidence, that in turn led to pronounced lateral variations in depositional environment. Three large-scale cycles of intensified evaporite sedimentation were interrupted by temporary changes towards brackish or freshwater conditions. They form three major base level cycles that can be traced throughout the basin, each of them representing a stratigraphic sub-unit. A relatively constant amount of horizontal extension (ΔL) in the range of 4–5 km has been estimated for the URG from numerous cross-sections. The width of the rift (L _f ), however, varies between 35 and more than 60 km, resulting in a variable crustal stretching factor between the bounding masterfaults. Apart from block tilting, tectonic subsidence was, therefore, largely controlled by changes in the initial rift width (L ₀). The along-strike variations of the graben width are responsible for the development of a deep, trough-like evaporite basin (Potash Basin) in the narrowest part of the southern URG, adjacent to shallow areas in the wider parts of the rift such as the Colmar Swell in the north and the Rhine Bresse Transfer Zone that delimits the URG to the south. Under a constant amount of extension, the along-strike variation in rift width is the principal factor controlling depo-centre development in extensional basins.  相似文献   

Analysis of kinematic seismic response of tapered piles   总被引：2，自引：0，他引：2  

Mahmoud Ghazavi 《Geotechnical and Geological Engineering》2007,25(1):37-44

In the present work, a two-phase analysis is used to assess the lateral movement of a tapered pile due to kinematic seismic loading resulted from earthquakes. First, the free-field horizontal displacement of the ground due to earthquake is estimated using available theory of wave propagation. Second, these estimated soil movements are imposed on the taper pile in a closed-form solution to compute the pile response. The governing differential equation for an arbitrary pile segment is obtained, which includes the free-field horizontal movement estimated from the first phase. The equation is solved explicitly to obtain the horizontal deflection. Parametric studies show that tapered piles tend to be more flexible than uniform piles of the same volume and length under earthquake loading, which is soundly interesting.  相似文献   

Local geoid determination combining gravity disturbances and GPS/levelling: a case study in the Lake Nasser area, Aswan, Egypt   总被引：1，自引：0，他引：1  

C. C. Tscherning  Awar Radwan  A. A. Tealeb  S. M. Mahmoud  M. Abd El-Monum  Ramdan Hassan  I. El-Syaed  K. Saker 《Journal of Geodesy》2001,75(7-8):343-348

 The use of GPS for height control in an area with existing levelling data requires the determination of a local geoid and the bias between the local levelling datum and the one implicitly defined when computing the local geoid. If only scarse gravity data are available, the heights of new data may be collected rapidly by determining the ellipsoidal height by GPS and not using orthometric heights. Hence the geoid determination has to be based on gravity disturbances contingently combined with gravity anomalies. Furthermore, existing GPS/levelling data may also be used in the geoid determination if a suitable general gravity field modelling method (such as least-squares collocation, LSC) is applied. A comparison has been made in the Aswan Dam area between geoids determined using fast Fourier transform (FFT) with gravity disturbances exclusively and LSC using only the gravity disturbances and the disturbances combined with GPS/levelling data. The EGM96 spherical harmonic model was in all cases used in a remove–restore mode. A total of 198 gravity disturbances spaced approximately 3 km apart were used, as well as 35 GPS/levelling points in the vicinity and on the Aswan Dam. No data on the Nasser Lake were available. This gave difficulties when using FFT, which requires the use of gridded data. When using exclusively the gravity disturbances, the agreement between the GPS/levelling data were 0.71 ± 0.17 m for FFT and 0.63 ± 0.15 for LSC. When combining gravity disturbances and GPS/levelling, the LSC error estimate was ±0.10 m. In the latter case two bias parameters had to be introduced to account for a possible levelling datum difference between the levelling on the dam and that on the adjacent roads. Received: 14 August 2000 / Accepted: 28 February 2001  相似文献   

Distribution and Influence of Iron Phases the Physico—Chemical Properties of Phyllosilicates     

MERVATSAIDHASSAN SAYEDMAHMOUDSALEM 《中国地球化学学报》2001,20(2):120-129

Clay minerals from different Cretaceous stratigraphic successions of Egypt were investigated using XRD,DTA,dissolution analysis(DCB),IR,Moessbauer and X-ray Electron Spin Resonance(ESR) spectroscopes.The purity of the samples and the degree of their structural order were determined by XRD.The location of Fe in the octahedral sheet is characterized by absorption bands at-875cm^-1 assigned as Al-OH-Fe which persist after chemical dissolution of free iron.The Moessbauer spectra of these clays show two doublets with isomer shift and quadrupole splitting typical of octahedrally coordinated Fe^3 ,in addition to third doublet with hyperfine parameter typical of Fe^2 in the spectra of Abu-Had kaolinite (H) sample.Six-lines magnetic hyperfine components which are consistent with those of hematite are confirmed in the spectra of both Isel and Rish kaolinite samples.Goethite was confirmed by both IR and DTA.Multiple nature of ESR of these clays suggested structural Fe in distorted octahedral symmetry as well as non-structural Fe.Little dispersion and low swelling indices as well as incomplete activation of the investigated montmorillonite samplas by NaCO3 appear to be due to incomplete disaggregation of montmorillonite particles.This can be explained by the ability of Fe-gel to aggregate the montmorillonite into pseudo-particles and retard the rigid-gel structure.However,extraction of this ferric amorphous compound by dithonite treatment recovers the surface properties of the montmorillonite samples.On the other hand,the amount and site occupation of Fe associated with kaolinite samples show an inverse correlation with the parameters used to describe the degree of crystallinity perfection,color,brightness and vitrification range of these kaolinite samples.  相似文献