旋挖桩斗式集渣两翼钻头扩底成孔施工技术

ROTARY DRILLING BUCKET MUCK-COLLECTING AND TWO FLANK-EXPANDING BOREHOLE-MAKING CONSTRUCTION TECHNIQUE

旋挖桩以其施工安全、快速、利于环保、机械化程度高、施工方便等优点广泛应用于建筑物基础工程。国内目前旋挖桩多采用机械旋挖成孔且成孔直径上下一致。为获得较大的桩基承载力,本文介绍了在常规旋挖钻机成孔工艺的基础上,当旋挖钻机钻孔至设计底标高后,将传统的一径到底旋挖钻头更换为自行研制的斗式集渣两翼扩底钻头进行扩底成孔施工,以达到机械旋挖扩底的目的,从而有效增加了桩端承载面积,单桩承载力或抗拔力显著增加,大大降低了桩基费用。

Rotary drilling pile construction is safe, fast, environmentally friendlier and convenient, has high degree of mechanization, and therefore is widely applied to foundation engineering of buildings. Mechanical rotary drilling is mostly used in hole-making and the hole has identical upper and lower diameters. To obtain a big pile bearing capacity, on the basis of routine rotary drilling hole-making technique, after drilling reaches designed bottom elevation, change the rotary drilling bit with a self-developed bucket muck-collecting twoflank expanding drilling bit to achieve mechanical bottom-expanding and effectively increase the pile end area for bearing, thus considerably improving single pile baring capacity or pulling resistance and then reducing pile foundation cost.