单项选择题
A.σCZ/σZ≤0.1 B.σCZ/σZ≤0.2 C.σZ/σCZ≤0.1 D.σZ/σCZ≤0.2
A.0.4m B.0.4l(l为基础底面长度) C.0.4b(b为基础底面宽度) D.天然土层厚度
A.10mm B.20mm C.100mm D.200mm