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51.
Siwa oasis is located in the extreme western part of the Egyptian western desert. There are several archaeological sites in
the oasis; the most distinct ones are Alexander the Great temple at Aghormi hill and the Gebel El Mota tomb excavations. They
have suffered due to deterioration and cracks of different kinds and some parts are getting worse as rock falls occur. From
field inspection and lab analysis, it is clear that lithology plays an important role on the extent of damage. Alexander the
Great temple was built over the northern edge of Aghormi hill, which consists of two distinct beds—an upper limestone bed
and a lower shale one. From field survey and laboratory analysis, the shale is considered as a high expanded bed and weak
in its bearing capacity, as its clay content (mainly smectite) experienced swelling due to wetting from the ground water spring
underneath. Consequently, the upper limestone bed suffered from map cracking associated with rock falls due to the differential
settlement of the swelled lower shale one. The temple was threatened by slope instability and had experienced many cracks.
At Gabal El Mota tomb excavations, it was noticed that a comparison of tombs of the same opening size revealed that those
that excavated on shale beds had cracked much more than those that excavated on limestone. This may be attributed to the low
bearing capacity of excavated shale walls. The remedial measures suggested to overcome the stability problems on these archaeological
sites are grouting or construction of retaining walls. 相似文献
52.
Maher Aldahri Saad mogren Kamal Abdelrahman Hani Zahran Sherif El Hady Mahmoud El-Hadidy 《Journal of the Geological Society of India》2017,89(4):435-443
Ten boreholes drilled in Ubhur area up to the depth of bedrock indicted the shallow depth of bedrock where the average depth ranges between 10 and 15 m. The standard penetration test N-values of these boreholes were measured and averaged. Based on N-values to the depth of bedrock, Ubhur area can be classified as site class C and D. Multichannel analysis of surface waves technique has been applied along seventy six profiles using 24-channel geophone array and 4.5Hz vertical geophones with 1m geophone spacing and sledgehammer and/or weight drop as seismic energy sources. Values of shear wave velocity to 30 m are calculated and then averaged (Vs30) where it ranges between 310.08 m/s and 1139.8 m/s. Therefore, Ubhur area can be classified into site class B, C and D based on site classification of the national earthquake hazards reduction program (NEHRP) recommendations. Accordingly, the greatest part of the study area falls in site class C while class B and D covered limited areas in the western and the eastern parts respectively. Depending on the shallow depth of bedrock in the study area, the Vs30 parameter is not applicable in the study area so the average values of Vs for the soil thickness, excluding the bedrock, have been calculated and mapped for site class C and D only. So Vs30 approach is not applicable for areas with shallow depth of bedrock which gives higher classification. 相似文献
53.
Roman Breuer Hani Sewilam Heribert Nacken Christiane Pyka 《Environmental Earth Sciences》2017,76(2):93
Based on the experience gained with SeCom2.0, we will explain the impact of game-based learning and provide an overview of the current use of Serious Games in teaching flood risk management in Germany. SeCom2.0 is a collaborative learning platform, which deals with a flood situation in Cologne. The use of Serious Games in flood risk management is still limited due to many factors. The article will give a deeper insight into the SeCom2.0 project, explaining the pedagogical design and the development. We will cover the pitfalls and possible suggestions for further development to facilitate wider use of such games by adapting the settings to local conditions. This article will also describe how a Serious Game can support lifelong learning for students and employees involved in flood risk management. The key components, design patterns and structure of or SeCom2.0 are described, along with ideas to implement selected topics in flood risk management in an engaging gaming environment. 相似文献