Aswan Dam: An example for Grout Curtain Application

In my Water Resources Engineering course, it was mentioned that before building a dam the foundation must be stable. The foundation must have less deformation under high loads, must have little to no permeability and seepage, increase shearing strength, and satisfy slope stability for the side hills. But regular foundation applications do not comply with the properties stated above. This is why grouting must be used. While I was searching videos about grouting, I came across this one:

In the video, the construction of the Aswan High Dam is being mentioned. This dam is very important for Egypt because of the drought problem and irrigation is now mostly provided by this dam. Periodic floods and droughts have affected Egypt since ancient times. The dam mitigated the effects of floods, such as those in 1964, 1973, and 1988. Navigation along the river has been improved, both upstream and downstream of the dam. 

Green irrigated land along the Nile amidst the desert

The base of the dam is nearly a wile wide and is the key to dam stability. As seen in the figure below, the dam has a core that must sit on the bedrock but in the region where the Aswan Dam is placed, bedrock is under 600 feet of silt and loose rock. So the most cost and time efficient solution was to transform a slice of the riverbed with a grout curtain. The workers drilled narrow holes lined with iron pipes into the sediment. Then the grout was pumped into the holes while the pipes were going up. This process was repeated hundreds of times until a grout wall was formed under the core. 

Source: 
(Water Resources Engineering, Yanmaz A. Melih, 2018)