捆绑式气动冲击锤嵌岩施工技术

Rock-socketed Construction Technique Using Binding Pneumatic Impact Hammer

气动冲击锤在国内外已被广泛用于硬岩地质条件下的工程施工,捆绑式气动冲击锤,可以直接一次性完成较单体冲击锤直径大得多的混凝土嵌岩灌注桩。文章介绍了两个工程实例:(1)采用捆绑式气动冲击锤对基岩直接出露的地基成孔,与爆破成孔相比,成孔规则,孔深相对较浅就能满足设计要求,成桩速度快。(2)用振动压管机压管、长螺旋钻取土和捆绑式气动冲击锤破岩的联合工法,可有效地解决桩长在20m左右嵌岩桩成孔难的问题。

Pneumatic impact hammers have been widely used for engineering construction in hard rocky geological condition at home and abroad. And a binding pneumatic impact hammer, compared with a single pneumatic impact hammer, can directly make rock-socketed grouting pile with much bigger diameter in once operation. Two engineering cases are introduced in this paper: (1) hole-making with a binding impact hammer in bared bedrock foundation. It is faster and has a better hole forming than blasting hole-making and meets design requirement even if the hole depth is smaller. (2) the combining method, i.e. using a binding impact hammer for breaking rock, a vibrating pressure pile machine for pressing pile and a long twist driller for recov- ering soil. It is able to solve the difficult hole-making problem of rock-socketed pile with a pile length over 20 m.