Retaining walls are a familiar sight in our modern world. With the advent of easily accessible concrete construction, retaining walls that create habitable and arable land has become commonplace. However the engineering of retaining walls is an ancient practice. Through my research I have found the earliest mention of Retaining walls being employed was by the Egyptians. In this article I will investigate the earliest origins of retaining wall technology.
Ancient Retaining Walls.
The Nile River was the lifeblood of ancient Egypt. The civilization rose and fell on its monsoonal tides, which brought rich silts for farming down river. But this powerful waterway was known to rise too high for the Egyptian people 7,000 years ago. Thus they would prepare simple ‘Gabion’ style baskets from reeds, that could be filled with soil and rocks to shore up a failing bank; nudging the flow of the mighty Nile where it would benefit these ancient people the most.
Gabion technology, whilst ancient, is a relatively modern term. It comes from the Italian Gabbione or big cage, and has its roots in Latin, from the word Cavea meaning cage. Gabion blocks are commonly used today when swift construction of earth works, retaining walls and even military emplacements are required. The salient factor in making modern steel Gabion cages so effective is that they can be collapsed and carried with ease and once an emplacement is required they are simply formed into shape and filled with rocks and soil. Thus making them an excellent tool for dealing with flash flooding, just as the Ancient Egyptians did thousands of years ago.
Walls of Ancient Stone
In a paper released by the British Museum author Angela La Loggia investigated the construction of temples and tombs at the ancient sites of Saqqara and Helwan in Egypt. The focus of the paper was to compare the construction methods of the ancients against modern engineering principles to determine how well those structures were designed.
There were seventeen tombs at Saqqara, with another twenty-five at Helwan and the tombs were all constructed to a similar blue print. The paper focussed on the construction and longevity of three main sections; the roof, the freestanding walls that compartmentalised the structure and the retaining walls that were used to support the excavated pit of the substructure and magazine walls.
There were eight tombs that had retaining walls at Saqqara and thirteen at Helwan. All the remaining tombs had their substructure carved from the rock strata therefore did not require the additional support of a retaining wall.
Of all of the tombs that had retaining walls supporting an inner substructure or providing support to the magazine walls, only one was found to have not survived the test of time. Rubble was piled around it to support the structure as the load bearing stone facing had crumbled and required shoring up. Many of the retaining walls had buttress load bearing walls to support the entire structure.
This clearly demonstrates that the ancient Egyptians had a thorough understanding of the load bearing structures and how to fortify a wall and that the Ancient Egyptian engineering was certainly of a modern standard.