Moderately weathered tuff and moderately weathered sandstone with high hardness. According to relevant information, sandstone is harder than limestone. Moderately weathered tuff:

1, grayish red, taupe, reddish brown, purplish red. There are no caves, free surfaces, broken rocks or weak rocks at the depth of the exploration hole. Moderately weathered sandstone:

2. As a building foundation, rock and soil can be divided into rock, gravel soil, sandy soil, silt soil, cohesive soil and artificial fill.