Type A soils are the most stable and can support vertical walls effectively. They have high shear strength, allowing them to remain intact when exposed. Other types like B and C are less stable and not suitable for such structures. ;
The soil classification that allows for vertical walls to remain intact while exposed is Type A soil, which has high stability and shear strength. Type B soils are less stable, and Type C soils are the least suited for such structures. Solid Rock is not considered in the context of this classification system for walls.
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