A.12N/mm2 B.16N/mm2 C.20N/mm2 D.30N/mm2
A.小于樁直徑的4倍時(shí) B.小于樁直徑的5倍時(shí) C.小于樁直徑的6倍時(shí) D.小于樁直徑的8倍時(shí)
A.6m B.9m C.12m D.15m