Existing drilling operating machineries are mainly adequate for soil categories Ⅰ to Ⅲ, only the anchor rig is used for soil categories Ⅳ to Ⅷ at present But it has unfavorable issues of slow rate, low efficiency, high cost, and long time limit for a project. Through the researches on air DTH hammer drilling technology boring principle and rock crumbling mechanism; successfully use the hammer in anchor construction in soil of categories Ⅳ to Ⅷ. Taking the anti-floating cable anchor project in the Wanda Plaza Jinan basement construction as an example, carried out borehole completion velocity, wall smoothness and volume scale comparative studies between conventional rotary drill and air DTH hammer operating in soil categories Ⅳ to Ⅷ, considered that in the relatively harder strata, using the hammer can consumedly shorten the net drilling time, improve drilling efficiency. Also due to durative percussion, creating perturbation back and forth time after time, thus expanded hole diameter and become irregular, thus can increase anchor body's lateral resistance, as well as local end bearing capacity come into being, and so can improve pull-out resistance. The analysis has demonstrated that to use the hammer in anchor construction in soil of categories Ⅳ to Ⅷ is practicable.%现有施工机械的研究主要是针对1、2、3类土的施工,对于4～8类土中锚杆的施工,现有的锚杆钻机显示出施工进度慢,施工功效低、费用高、工期长、造价高等不利问题.通过对空气潜孔锤钻进技术成孔原理及碎岩机理的研究,成功的把它应用于4～8类土中锚杆的施工中去.以济南万达广场地下室抗浮锚索工程为例,通过对常规回转钻机和空气潜孔钻机在4～8类土中成孔速度、孔壁光滑度和孔体积大小对比研究,认为在相对较硬的地层中,采用空气潜孔锤钻进能大大缩小纯钻机时间,提高钻进效率,而且由于持续的冲击作用,会对孔壁造成多次来回扰动,增大了孔径,同时让孔径变得不规则,这在一定程度上增大了锚杆体的侧阻力,以及产生了局部端承力,从而提高了锚杆的抗拔力.通过分析说明,把空气潜孔锤冲击成孔技术运用在4～8类土锚杆的施工中是切实可行的.
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