排序方式: 共有5条查询结果,搜索用时 15 毫秒
1
1.
The stresses generated in the interlock T-junction piles of steel cellular structures used as quays are analysed based on a full scale experimental recording of the stresses in the piles at all stages of construction. Special emphasis is placed on the resonant response of the pile to vibrations of the fill in the interlock cell. Means of stiffening the interlock piles are discussed. A model for the statical behaviour of the interlock pile is postulated and an alternative design for cellular quay construction based on its three-dimensional behaviour rather than the equivalent breadth concept is put forward. This work was instigated by the collapse of three interlock piles during the construction of the deep water quays at Umm Said Port in Qatar. 相似文献
2.
Abdessalem El Ghali Noureddine Ben Ayed Claude Bobier Fouad Zargouni Anis Krima 《Comptes Rendus Geoscience》2003,335(9):763-771
In central Tunisia, a synsedimentary tectonic episode has been pointed out through the tectonic movements affecting the Late Palaeocene–Early Eocene successions. This tectonic episode has controlled, to a large extent, the palaeogeographic setting of the area during that period and confirmed the important effect induced by the Pyrenean shortening phase on the edge of the African plate, which obviously has witnessed a common history with the southern part of the European plate. To cite this article: A. El Ghali et al., C. R. Geoscience 335 (2003). 相似文献
3.
Acta Geotechnica - In the last few decades, several empirical correlations of SPT-N with geotechnical parameters of sand have been developed based on conventional field and laboratory test results.... 相似文献
4.
Neotectonic and seismotectonic investigation of seismically active regions in Tunisia: a multidisciplinary approach 总被引:1,自引:0,他引:1
N. Bahrouni S. Bouaziz A. Soumaya N. Ben Ayed K. Attafi Y. Houla A. El Ghali N. Rebai 《Journal of Seismology》2014,18(2):235-256
Due to its key position within the Africa–Europe convergence zone, Tunisia is marked by thrusting, folding, and faulting and has a major rupture zones associated with active faults. Consequently, most of Tunisian land is seismically active with significant active deformations, showing recent seismic events and their relative surface effects. This paper reports on several aspects of the seismotectonics, historical, and present-day seismicity and places them in the general tectonic and geodynamic framework of Tunisia. Field investigations, based on an integrated multidisciplinary approach, included (1) the identification of active faults, their motion and displacement, geomorphic aspects, and scarps and their relation with the general structural map of Tunisia and (2) an extensive analysis of brittle tectonic deformation affecting Quaternary deposits in several sites throughout Tunisia. The integration of field data within the existing data related to the seismic events that took place during the last decades allowed the establishment of an earthquake distribution map, as well as major seismic zones for better understanding of the seismicity database of Tunisia. To establish microzonation maps in seismic regions such as Gafsa and its surroundings, we have analyzed surface effects and secondary structures associated with active faults and correlated them with deformation rates, reconstructed for significant seismic events. Most faults exhibited typical left-stepping en-echelon with strike-slip component pattern suggesting that Tunisia is presently subjected to NNW–SSE compression. The focal mechanism of most Tunisia earthquakes combined with the existing tectonic and structural information and reconstruction of the Quaternary stress tensor allowed (a) better understanding of seismic zoning, (b) provided better assessment of the seismic hazard, and (c) facilitated the interpretation of the relationship between seismic zones and the geodynamic African–Eurasian plate boundary. 相似文献
5.
S. Morad M. A. K. El‐Ghali M. A. Caja M. Sirat K. Al‐Ramadan H. Mansurbeg 《Geological Journal》2010,45(1):105-116
Petrographic examinations and electron microprobe analyses of Proterozoic granitic rocks, SE Sweden aimed to characterize and unravel the mechanisms and conditions of plagioclase alterations. These alterations include saussuritization, albitization and replacement of plagioclase by K‐feldspar. The hydrothermal alterations, which are inferred to have occurred at ca. 250–400°C, resulted in concomitant formation of Al‐rich titanite, epidote, calcite, pumpellyite, prehnite and iron oxides. Replacement of plagioclase by K‐feldspar occurs in red‐stained zones, which have developed close to thin fractures owing to the precipitation of tiny Fe‐oxide pigment particles within the altered plagioclase, whereas saussuritized plagioclase has less systematic spatial relationships to these fractures. Albitization of plagioclase occurred in rocks that are poor in biotite compared to rocks that suffered extensive saussuritization. The chemical and textural characterization of various types of plagioclase alterations allows elucidation of the granitic hydrothermal systems. Features of feldspar alteration in the granitic rocks are similar to those encountered in feldspathic sandstones and should hence be considered in studies on diagenetic changes of siliciclastic successions during basin evolution. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
1