无桩尖沉管灌注夯扩桩由于经济效益较高,已在我省逐步推广,然而目前尚无定型的专用机械,本文介绍利用D1-1800导杆式柴油打桩机改制的经验,供参考。一、沉管系统 1.桩管用ф377或ф325mm的无缝钢管制成,作为混凝土灌注的成型管,在钢管的上部焊有2只用厚25mm钢板制成的耳朵(图1)。 2.内夯管长度与桩管(外管)相等,由ф219×10无缝钢管制成,其上端焊有法兰,与特制桩帽用螺丝联接,下端至200mm处焊成一只夯头,直径比外管内径小10mm,夯头封底钢板厚度不小于20mm,内夯管壁 The pile-less immersion boring pile expansion pile has been gradually promoted in our province due to its high economic benefit. However, there is no special type of special machinery at present. This paper introduces the experience of using the D1-1800 guide rod type diesel pile driver for reference. First, the immersed tube system 1. The pile tube is made of ф377 or ф325mm seamless steel tubes. As the molded tube filled with concrete, two ears made of 25mm thick steel plate are welded on the top of the steel tube (Fig. 1). 2. The length of the inner manifold is equal to that of the pile pipe (outer pipe). It is made of ф219×10 seamless steel pipe. The upper end is welded with a flange, and the special pile cap is screwed, and the lower end is welded to a 200 mm end. The diameter is 10mm smaller than the outer diameter of the outer tube, and the thickness of the steel plate on the back of the hammerhead is not less than 20mm.