How were western desert sections of the Great Wall constructed?

In the western desert regions, the Great Wall of China was constructed as a relatively simple structure composed primarily of rammed earth and adobe.1

The technique of rammed earth involves compacting soil—typically a mixture high in sand and low in clay—into a form to create durable walls or blocks. When building these walls in place, workers used two wooden planks separated by a spacer bolt as a mold. Earth was then rammed into this form in layers until the desired height was achieved, at which point the form was moved upward to continue the process. This method provided the structure with good compressive strength, which was well-suited for the environmental conditions of the western frontier.21