What type of soil is recommended when placing thrust blocks?

The recommended type of soil for placing thrust blocks is undisturbed soil. This is because undisturbed soil typically provides a solid and stable base, which is essential for the effective distribution of the forces exerted by thrust blocks. When thrust blocks are installed, they need to transfer the forces from the pipe, especially at bends or transitions, into the ground without significant movement or failure.

Undisturbed soil retains its natural structure and density, offering greater resistance to the loads imposed on it by the thrust blocks. This stability is crucial to prevent any potential shifting or settlements that could compromise the integrity of the pipeline system. In comparison, loose gravel, sandy soil, and clay soil may not offer the same level of support and could lead to issues such as erosion, shifting, or insufficient load-bearing capacity, ultimately affecting the performance of the thrust blocks and the overall pipeline system.