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The pyramid shaped building is suitable in earthquake prone area due to its higher stiffness and less displacement. The only earthquake that affected the pyramids was in the 14th century on August 8, Later, explorers reported massive piles of rubble at the base of the pyramids left over from the continuing collapse of the casing stones which were subsequently cleared away during continuing excavations of the site.
Nevertheless, many of the outer casing stones around the base of the Khufu Pyramid can be seen today in site, displaying the same workmanship and precision as has been reported for centuries [ 19 ].
Arabic sources reported that this earthquake was the strongest in Egypt, particularly in Alexandria. In Cairo, almost all houses suffered some damage and many large public buildings collapsed. The earthquake caused panic, and women run into the streets without their veils.
Minarets of the mosques of Cairo were particularly affected. In Alexandria, many houses were ruined and killed a number of peoples. The lighthouse was shattered and its top collapsed. The damage extended to Southern Egypt up to Qus. This earthquake was placed by Sieberg to Faiyum, south of Cairo because of the severe damage in Middle Egypt.
It was also reported that this earthquake caused large-scale damage in Rhodes and Crete. Ambraseys [ 23 ] placed its epicenter in the Mediterranean Sea as As-Souty mentioned that the advance of sea submerged half of Alexandria. According to Arabic sources e.
El-Maqrizy; As-Souty aftershocks continued during 3 weeks [ 18 ]. Recently the present area is near to relatively active earthquake area to the west of downtown Cairo. In that area, the most destructive event in recent history of Egypt took place in October 12th, The epicentral distance is only about 30 km. Damage report after that earthquake showed that great pyramids at Giza were severely damaged, and few years later a restoration plan was inaugurated to save the pyramids from more damage and instability problems.
In addition, other earthquake activities are also observed at east Cairo, like Aqaba earthquake in But Dahshour seismic zone constitutes the epicenter of the 12th October Cairo earthquake, and other seismic activity area produced earthquakes with magnitudes seldom reaching a magnitude of 5. However, due to their proximity from the dense population Cairo metropolitan, such earthquakes were widely felt in greater Cairo area. The seismic zone at Dahshour is only few kilometers from the pyramids complex.
The epicentral distance between Cairo earthquake and pyramids is few kilometers only. This proximity indicates that Dahshour seismic zone might have the highest effect especially at short periods. Most of the typical land failure effects were as extensive as soil liquefaction [ 24 ]. Giza Governorate was exposed to liquids during the 12 October earthquake [ 25 ]. Soil liquefaction has been reported in Giza. Since this is the last major earthquake affecting the monument, it is possible to assume that the present deformed form and the cracking of the inner chambers and the inner and outer stone layers [ 26 , 27 , 28 , 29 ].
According to the Egyptian newspaper Al-Ahram in 13 October , several small outer casing blocks on the top of the great pyramid and supporting panels fell down during the Dahshuor earthquake It is important to note that after the first earthquake, permanent distortions and therefore moments of permanent curvature remain, so that global behavior, even in the case of low-level earthquakes, becomes weaker and weaker.
The structure is weakened after earthquakes between the blocks and deformations of the exits and pressure in the walls; from this point of view, the current situation is worse than in the past, as shown in Fig. The increasing weakness of the structure after earthquake causing the friction and sliding between the casings and filling blocks.
Show extremely slow degradation process which affected the backing stone blocks of the great pyramid, many blocks were detached. The outer casing stone blocks fell down completely in strong earthquake. The increasing weakness of the structure after earthquake causing the friction and sliding between the facing and backing blocks.
After the earthquake, the Giza pyramids remained deserted and thus suffered a gradual deterioration. Attention initially focused on the lateral boundaries of the remaining facades, where discontinuity and consequently the disappearance of peripheral stress led to a very disadvantageous situation, exacerbated by the dynamics that affected the current boundaries of the areas at risk. Some cracks affect specific elements such as thresholds for openings, doors and foundation stones, as shown in Fig.
Cracking of backing limestone blocks due to the overloading and material decay and strength regression, which affected the great pyramid stability. The honey comb differential weathering aspects are obvious on the surfaces of backing limestone blocks.
The outer facing limestone blocks are missed completely. Alveolization develops her as cavities illustrating a combination of honeycombs and alignment following the natural bedding planes of the limestone. It is difficult to determine the actual degree of stability. Despite this uncertainty, the state of internal pressure of the structure, on the contrary, is well defined.
Loss of balance cannot occur during the adjustment. This is the correct aspect of the behavior of building structures that can explain the great durability and longevity of many historic buildings.
The old builders were not Civil engineers. There is something unique in the behavior of construction structures. This is due to the mechanical construction response, and differs significantly from those shown by the usual flexible materials. The difference is due to the low tensile strength of the construction and to the different response of the construction in stresses [ 30 ]. The pyramids were severely damaged on the surface of lower-level stone walls due to long-term static and dynamic actions, extensive cracks in walls caused mainly by settlements, and only because of seismic loads while the foundation stone sites were specifically removed.
The climatic conditions in the study area are semi-arid; warm in winter with little rain and hot to dry in summer. The climate is characterized by the following parameters. With regard to precipitation, the average annual rainfall does not exceed 25 mm, which is generally rare throughout the year, sometimes occurring in the form of sudden and short showers associated with wind. For winds, the prevailing wind blows are from the northwest and the monsoon known as Khamasin from the southwest and south.
The great pyramids at Giza and have been threatened by rising groundwater levels caused by water infiltration from the suburbs. Irrigation canals, mass urbanization surrounding GPP, as shown in Fig.
Two regional aquifers are located behind the Sphinx statue with a water level at a depth of 1. The recharge of the aquifer underneath the Sphinx area occurred mainly through diversion of the water network and overall urbanization. The shallow water table elevation at Nazlet El-Samman village reaches 16—17 m and might recharge the aquifer below the Sphinx and Valley Temple, which is considered a severe hazard on the site [ 7 ].
There is deterioration in many parts of the three pyramids, associated with the aging of materials and the impact of aerial and ground water attack, and extreme stresses and cracks have accelerated the related phenomena, as shown in Fig.
Many blocks was detached and are hanging. Also represents the extremely slow degradation process which affected the backing limestone blocks of the Mykerinos, pyramid. The scattering of the granite facing blocks around the pyramid area is obvious.
The pyramids stones are characterized by minute cracks, thin and superficial fractures, gaps in the stone veneer, separate stone layers and large gaps below the surficial hard crust. The backing limestone of the three pyramids are characterized by deep and hollow pits on the surface crust. They are very thin and are based only on a few points. Some parts have lost their shell, and for this reason, large parts are characterized by strong separation.
A severe phenomenon is the separation and peeling of the limestone layer due to the capillary rising of ground water, as shown in Fig. The backing limestone blocks characterized by weak cementation and adhesion due to the presence of small cracks, or pores, of secondary origin resulting from salt weathering. Our analysis showed that the poor state of conservation of the three pyramids can be attributed to two main factors: internal or intrinsic causes, related to the characteristics of the fossil limestone itself e.
While the latter began the process of weathering on limestone blocks, the development and increase of this process is due to lack of cohesion in limestone cement. In fact, the very poor state of maintaining interior walls is due to several internal factors, as in the past, are strictly interconnected. On the other hand, external causes are associated with daily-acute environmental factors Seasonal thermal changes, solar radiation, wind direction and density—work in synergy with the internal causes of limestone degradation.
The most obvious and most common phenomenon is peeling or lids due to the capillary rising of ground water, specific both on the surface, in the form of high elevated chips, deeper parts, with thick detachable layers of limestone blocks.
The layer is associated with temperature changes that cause the expansion and contraction cycles of the material, resulting in strong mechanical pressures. Cracking within crystals is also very common in the fragile deformation of posterior limestone blocks characterized by high gaps. Means within crystals not between crystals. In highly penetrating stones, pressure builds up through the grain—the grain contact becomes large because the forces spread over very small areas stress is the strength of each area , making it easily breakable internally than if porosity is small or non-existent.
Moreover, the behavior of building materials under weathering conditions is predicted by the design of the element and constructive elements. On the other hand, there are some specific weathering forms that affect different granite blocks depending on the surrounding environmental conditions such as red crusts that dominate the case study of aggressive alternative drying and urination cycles, as well as other chemically or biologically related degradation factors for the weathering rates of silicate minerals.
Thus, it can be emphasized that the particular weathering model that characterizes our effects is due to all these factors and associated mechanisms; they consist mainly of complex types of iron oxide-dyed clay minerals. All these factors above require some conservation measures to protect the monuments through various scientific strategic plans containing many preventive and multiple measures. The pyramids used to be cased. The backing limestone blocks of Chephren pyramid was covered and cased with fine limestone blocks, also the stone cap now remain on the top of the Chephren pyramid.
The Mykerinos pyramid was covered and cased with granite facing blocks were quarried and imported from Aswan quarry, km from Cairo. Many facing blocks were taken and reused for the buildings of many Coptic and Islamic monuments in Cairo city, revealing the Fossiliferous limestone backing blocks.
Having this fact, and investigating the formation of the stones of the building material of the pyramid and the ground surface where pyramids were built, one could easily find that the former one was chosen from the upper stratum of Eocenean site while the latter one is the original lower dense stratum of the Eocenean which was used as a base for the structure, as shown in Fig. By mentioning that, the sum of masses of the pyramids almost reached That was the net weight of the blocks but, if we consider the wasted ruble resulted from shaping the blocks that number could easily have been doubled i.
So, that height was used as the building material in situ for the pyramid. Having that elevation of the original plateau, the logic tells the fact of transposing the huge masses extracted from the high levels to levels below, and eight ramps were used to roll blocks down. There is an example of such a ramp in front of the second pyramid [ 32 ]. It is noticed that the Great Pyramid was built on a carved outcrop using the existing topography at the time of its construction.
From the observations made in the digging of boats, in the northeast corner of the pyramid of Khufu and on the deck around the pyramid, we have seen that the rocky base of the monument consists primarily of nummulitic packstone. However, it is possible to prove the existence of an original rocky hill. X-ray diffraction was also used to identify minerals for whole stone powders and clay part.
Semi-quantitative data are given for each metal present by their relative density the metal composition was determined by X-ray diffraction analysis, which was conducted through the National Center for Housing and Building Research in Cairo. Graphs of the representative body of limestone, specimens of structural limestone layers and samples of structural mortar layers were recorded. The outer casing limestone consists of a whitish to whitish-yellow, very fine-grained limestone and can be easily distinguished from the heterogeneous filling limestone blocks with its much coarser microstructure.
Many of the outer casing stones and inner chamber blocks of the Great Pyramid were fit together with extremely high precision. Tura limestone formations were used as coated casing stones to cover the local limestone filling blocks of the Great Pyramid of Khufu. Although some of the casing remains, most have been removed. However, each of the ten stones discovered had inscriptions on the back sides.
It may be extracted from Tura quarry that belongs to the Mokattam Plateau. Hair and cracks are filled with fine stone with dust and soft sand. The upper units are indicated by weak limestone blocks with structural mortars. The layers of backing limestone blocks which is irregular in size can be observed, these layers constitutes up to four courses lie between the outer casing layers and the core masonry, this core is not exposed.
The backing limestone blocks of Cheops great pyramid is composed mainly of calcite CaCO 3 as the essential component associated with minor amount of iron oxides and quartz SiO 2 and rare of dolomite CaMg CO 3 2 , opaque minerals and halite NaCl.
Results of XRD pattern are presented in Table 3. The more eastern parts of this central quarry field were generally exploited by Khafre to gain core material for his pyramid. The structural mortar joining the backing limestone blocks composed of gypsum Ca SO 4 H 2 O 2 , rock fragments composed of calcite and dolomite CaMg CO 3 2 , biotite, muscovite and rare quartz grains cemented by very fine-grained matrix of gypsum, anhydrite CaSO 4 , calcite admixed with minor iron oxides.
The analysis results are presented and summarized in Table 4. The structural mortar joining the filling limestone blocks is composed of gypsum Ca SO 4 H 2 O 2 , anhydrite and rock fragments composed mainly of calcite associated with minor amounts of quartz, biotite, iron oxides and opaques cemented by very fine-grained matrix of gypsum admixed with calcite, anhydrite, halite and iron oxides. The analysis results are presented in Table 6. Secondary minerals are represented by iron oxides sericite and clay minerals.
The analysis results are presented in Table 7. The backing limestone blocks of Mykerinos, pyramid is composed mainly of calcite CaCO 3 as the essential component associated with minor amount of iron oxides and rare amounts of quartz, gypsum and opaque minerals.
Results of XRD pattern are presented in Table 8. In the present study more than 6 mortars samples were analyzed in terms of determination of chemical composition and salt content. In an effort to correlate the salt content with the role and structure of the structural joining mortars. The structural mortar joining the backing limestone blocks is lime based mortar and composed mainly of Calcite, magnesian Mg.
The analysis results are presented in Table 9. Microscopic examination and initial partial analysis on the front and back stone blocks and structural slurry samples from the three great pyramids were performed by the SEM attached with EDAX to study the texture, cement texture, fine image pores and the remaining carbonate portion on the filter paper to also identify structural mortar elements.
The morphological investigation indicate that the Fossiliferous limestone Biomicrite bodies from the three pyramids contain different surface features, such as the wide distribution deteriorated crusts, corroded quartz grains and the presence of some large voids and micro pores, as well as, some disintegration aspects in each grain, as shown in Fig. Observations of minute and deep cracks in the microstructure and salt crystallization into.
A strong Calcium signal is observed. The micrographs show the reaction interfaces, service environment and degradation mechanism of the backing limestone blocks. The composite structure of the stone is obvious where the disconnecting between the quartz and calcite grains is clear, also the abundance of salt content inside the pores and cracks between grains. Deterioration of stone grain surface as a result of the weathering and mechanical factors.
A strong calcium signal is observed. SEM observations indicated that there is a relative deposition of calcium from the binder due to physical and chemical actions that reduced alkalinity and strength and increased absorption of this lime mortars. The lime linker becomes less hydraulic but has the highest resistance to perfusion, and some observations have indicated the presence of a condensed halite within the mortar composition. The presence of carbon and organic residues within the mortar composition was also apparent, as shown in Figs.
Amorphous silica are participated on the limestone surfaces. A strong Calcium, sulphur and silica signals are observed. The micrographs show the characterization of the building material structures, contaminant analysis on and within building materials. The open pits and pore holes due to extensive weathering is obvious.
Amorphous silica is participated on the limestone surfaces. Individual calcite grains are approximately 2. The energy-dispersed X-ray spectrometer EDS is a powerful tool for research studies on building materials, particularly structural mortars. Elemental quantification contained in a gypsum mortar microscope can be performed at excellent spatial accuracy. Examination of all samples shows the use of stone fragments in mortar as filler or coarse raw material, and in the relevant EDX analysis showed Ca and Si.
For the structural mortar collected from the pyramids of Cheops and Chephren, the results obtained indicate the presence of Ca, Si, O, S, Cl, Na, and C elements as the main elements in the formation of mortar, suggesting that the structural mortar in these two pyramids is a cannon Gypsum mortar gypsum and sand , as shown in Figs. In addition to the presence of calcite and iron oxide aggregates, the presence of sodium chloride due to salt contamination Fig.
The presence of carbon residues and scorched organic matter represented in phosphorus, nitrogen and oxygen P, N, C. While the results obtained from samples collected from the pyramid of Mykerinos revealed that the structural mortar is lime mortar. Observation of minute and deep cracks in the mortar structure and salt crystallization into mortars.
A strong Calcium and silica signals are observed. The morphology of aggregate granite surfaces evaluated by SEM and the results obtained show that the confrontation blocks have been severely affected by various dynamic procedures and physical—chemical action, especially weathering factors that lead to some degradation effects such as: Degradation and fracture of shapes in addition to filling the gaps between grains, Fig.
The accumulated particles consist of some types of clay minerals and salts. Create red crusts, small cracks and other forms of degradation, Fig. Micrographs show heavy materials disintegration and few trace elements are slightly immobile, whereas most major particularly Ca and Na and trace elements are mobile from the beginning of the granite weathering. On the other hand, there were mineralogical changes initiated from a plagioclase breakdown, which shows a characteristic circular dissolved pattern caused by a preferential leaching of Ca cation along grain boundaries and zoning.
The biotite in that region is also supposed to be sensitive to exterior environmental condition. Only 20 miles to the north of Memphis is the modern capitol, Cairo, still situated near the juncture of the Nile valley and the delta. How does the pyramid fit into early Egyptian life? Pyramids today stand as a reminder of the ancient Egyptian glorification of life after death, and in fact, the pyramids were built as monuments to house the tombs of the pharaohs.
Death was seen as merely the beginning of a journey to the other world. Part-time crews of laborers probably supplemented the year-round masons and other skilled workers. The Greek historian Heroditus reported in the fifth century BCE that his Egyptian guides told him , men were employed for three months a year for twenty years to build the Great Pyramid; modern estimates of the number of laborers tend to be much smaller.
Pyramid building was at its height from the Fourth through the Sixth Dynasties. Smaller pyramids continued to be built for more than one thousand years. Scores of them have been discovered, but the remains of others are probably still buried under the sand.
As it became clear that the pyramids did not provide protection for the mummified bodies of the kings but were obvious targets for grave robbers, later kings were buried in hidden tombs cut into rock cliffs. Although the magnificent pyramids did not protect the bodies of the Egyptian kings who built them, the pyramids have served to keep the names and stories of those kings alive to this day.
Ancient Egypt The Egyptian Pyramid. National Postal Museum 10p Sphinx and Pyramid single. Second Pyramid with crown of original casing masonry, S. Looking up the N.
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