鑽孔灌注樁 沉管灌注樁 人工挖孔樁 預應力混凝土管樁 靜力壓樁機 國家標準 行業標準 正常使用極限狀態 承載能力極限狀態 淤泥 Bored pile Withdrawable-tube pile Hand dug caisson Pre-tensioned spun concrete pile Hydraulic jacking machine National standard Professional standard Limit state of serviceability Limit state of load bearing capacity Muck