How do pyramids built

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. A strong silica, aluminum and potassium signals are observed. It seems that some rock-forming minerals in the granitic facing blocks are significantly unstable due to the environmental condition. A strong silica signal is observed. Chemical analyzes of red weathering spots diameter 3. These results can be summarized as follows:. Thin section analysis was performed to study the cement texture, porosity and permeability.

Ten thin sections were prepared for the petrographic study of the sandstone and limestone body and slurry was incorporated to determine the mineral composition and experimental processes of the studied building material samples. It is important to examine the building materials and the construction of the three great pyramids under polarized light microscopy, to determine the basic type of building materials building stones and structural mortars and to identify the original quarries for these stones and building materials.

This method relies on polarized light that passes through a thin section of the sample. Texture: The rock is very fine to fine-grained. Microfossils of different sizes and shapes are present in a significant amount, scattered in the rock matrix. Few pore spaces irregular shapes and sizes are present in heterogeneous distribution in carbonate matrix of the rock. Mineral composition: the rock is composed mainly of calcite as the essential component associated with minor amount of iron oxides and quartz and rare of dolomite, opaque minerals and halite.

Calcite represents the majority of the matrix of the rock. Dolomite is very fine to fine-grained, subhedral crystals and associated with calcite. Quartz occurs as fine to very fine-grained Anhedral crystals scattered in the rock.

The rock is highly stained by iron oxides in some parts Fig. Microscopic photograph shows the backing Fossiliferous limestone Biomicrite blocks of Cheops pyramid, which composed mainly of calcite as the essential component associated with minor amount of iron oxides and quartz and rare of dolomite, opaque minerals and halite.

These limestones are of a grey-beige to yellow—brown colour, mostly compact but also porous in places, and they feel chalky due to marly components. Many of small-sized fossil remains are detectable but hard to identify. Occasionally, small nummulites up to 5 mm in length could be recognized at polished surfaces.

During storage over a longer period, various salts effloresce at the surface, which can be washed off easily with the finger. With a hand lens, the fossils appear mostly as small nummulites, shells and other fossil remains, all irregularly imbedded and mostly secondarily calcified within the limestone matrix.

The present study confirms that the building stones of the pyramids are natural rocks and were not formed by using artificial concrete. Texture: very fine to coarse-grained, showing prophyrtic texture fine to coarse-grained of rock fragments gypsum, biotite, muscovite and rare quartz grains enclosed in a very fine-grained matrix.

Many irregular pore space are detected in the sample. Mineral composition: The sample is very fine to coarse-grained and composed of gypsum, rock fragments composed of calcite and dolomite , biotite, muscovite and rare quartz grains cemented by very fine-grained matrix of gypsum, anhydrite, calcite admixed with minor iron oxides.

Minor amounts of mafic minerals biotite and muscovite and opaque minerals are observed scattered in the sample. Rock fragments are represented by fossiliferous limestone, dolostone, gypsum and anhydrite. Rock fragments occur as medium to coarse-grained of rounded to subangular outlines, scattered in the sample matrix.

Quartz occurs in rare amounts as very fine to fine-grained of rounded to subangular outlines cemented by a mixture of very fine-grained cement matrix. Iron oxides and opaque minerals occur as very fine to medium-grained scattered in the sample. Mafic minerals present as very fine to fine-grained, and observed in the matrix of the sample.

Many of irregular pore spaces and cavities are detected in the sample Fig. Microscopic photograph shows the structural mortars joining the backing limestone blocks of Cheops pyramid.

The joining mortar is very fine to coarse-grained and composed of gypsum, rock fragments composed of calcite and dolomite , biotite, muscovite and rare quartz grains cemented by very fine-grained matrix of gypsum, anhydrite, calcite admixed with minor iron oxides. Texture: The sample is very fine-grained.

Some microfossils of different sizes and shapes are observed in the rock matrix. Mineral composition: the rock is very-grained and composed mainly of calcite as the essential component associated with rare amounts of iron oxides, microcrystalline quartz and opaque minerals.

Calcite represents the matrix of the rock and occurs as very fine-grained micrite , anhedral to subhedral interlocked crystals. Quartz is detected as very fine-grained crystals scattered in the matrix.

Some microfossils of different sizes and shapes are observed scattered in the carbonate matrix. Microfossils are mostly filled by recrystallized calcite. Some pores of irregular shapes and various sizes are observed scattered in the rock.

Some parts of the sample are stained by iron oxides Fig. Microscopic photograph shows the backing Fossiliferous limestone Biomicrite blocks of Chephren pyramid. The limestone is very-grained and composed mainly of calcite as the essential component associated with rare amounts of iron oxides, microcrystalline quartz and opaque minerals. Texture: very fine to coarse-grained, showing prophyrtic texture fine to medium-grained of quartz, gypsum and rock fragments enclosed in very fine-grained matrix.

Significant amounts of irregular pore space are detected in the sample. Mineral composition: The sample is composed of gypsum, 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. Quartz occurs as fine to medium-grained of rounded to subangular outlines and some of which are cracked.

Quartz grains are cemented by a mixture of very fine-grained cement matrix. Rock fragments are represented by limestone, gypsum and anhydrite which occur as medium-grained and rounded to subangular in sample. Significant amounts of irregular pore space and cavities vugs are detected in the sample Fig.

Microscopic photograph shows the structural mortars joining the backing limestone blocks of Chephren pyramid. Very fine to coarse-grained, showing prophyrtic texture fine to medium-grained of quartz, gypsum and rock fragments enclosed in very fine-grained matrix. The sample is composed of gypsum, 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.

Texture: the rock is medium to coarse-grained showing, equigranular, hypidiomorphic, perthitic and piokilitic texture. Mineral composition: the rock is composed mainly of potash feldspar microcline, orthoclase and perthite , quartz and plagioclase associated with considerable amounts of hornblende and biotite and accessory amount of muscovite, titanite, zircon and opaque minerals.

Potash feldspar microcline, orthoclase and perthite is the most abundant constituent of the whole rock. It is medium to coarse-grained, generally subhedral to anhedral crystals and slightly altered to clay minerals. Plagioclase replaces and forms fine lamellae perthitic intergrowths over microcline showing perthitic texture.

Quartz is an essential mineral constituent occurs as fine to coarse-grained, anhedral crystals. It also presents as crystal aggregates that fill in the interstitial spaces between feldspar crystals. Quartz shows stretched, sutured, fractured and curved boundaries due to mild deformation process.

Plagioclase is medium to coarse-grained, subhedral platy in form and shows distinct lamellar twinning. Plagioclase is slightly altered to sericite.

It presents also as irregular lamellae, thin films and fine inclusions intergrowths in microcline perthite. You will have to crawl and crouch.

And all the way on the top, above the relieving chambers, are two huge blocks of stone forming a triangle, an inverted triangle, like a pyramid. That takes the pressure off the relieving chambers, so all the force of the weight of the pyramid is distributed throughout the pyramid, away from the ceiling.

Learn more about ancient Egyptian thought. There are some very interesting questions about the Great Pyramid. How do you get the stones all the way up to the top? There are two theories. One theory is the ramp theory: you build a long ramp and the stones are hauled up the ramp, and once you finish the pyramid you remove the ramp. Now, for something the size of the Great Pyramid, going feet up in the air, the ramp would have to be more than a quarter of a mile long.

The ramp would be a major engineering project. But we do know they used ramps because at Karnak Temple against one of the walls is a mud-brick ramp that they used to get blocks up. So perhaps they used that technique.

The other possibility is what we call a switchback. It goes around and around and around. They may have had the equivalent of a switchback road corkscrewing up around the pyramid until you get the blocks up and then you start filling in. These are the two theories. For example, another careful measurement was that the sides of the Great Pyramid were perfectly aligned on the four compass points: north, south, east, and west.

Egyptians knew how to do that by carefully observing the stars. They could do that with the North Star, so one could do that. This required great workmanship but not high-tech stuff.

For example, some of the limestone casing blocks are still in place. You cannot fit a piece of paper between them, they are so perfectly fitted. And think about it, all of it was done within 22 years, the reign of Khufu.

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