“福兰克”(Franki)桩为西德福兰克公司的专利,已有20年以上的使用历史。这种桩基的施工方法,在一般土壤的情况下,先用螺旋钻孔机成孔,在孔中下沉钢套管。当地下水位高,有泥砂时,用泥浆泵将其抽出。如下面有坚硬的土、石,则改用旋转抓斗或冲击抓斗将土、石破碎取出或抽出,一边吸泥砂,取土、石,一边下沉钢套管。钢套管的下沉主要依靠自重及本身的转动。为了减轻钢套管下沉时与孔壁间的摩擦力以及 The “Franki” pile is a patent of the West German Frank Company and has been used for more than 20 years. This kind of pile foundation construction method, under the general soil condition, first uses the spiral drilling machine to make the hole, sinks the steel sleeve in the hole. When the groundwater level is high and there is mud sand, pump it out with a mud pump. If there is a hard soil or stone below, use a rotary grab or an impact grab to remove or extract the earth and stone. While sucking the sand, take the soil and stone and sink the steel casing. The sinking of steel casing mainly depends on its own weight and its own rotation. In order to reduce the friction between the steel casing and the hole wall when sinking