采用组合钻具进行跟管钻进，通过随钻跟入的套管保护孔壁，解决因钻孔垮塌导致钻探效率和岩心采取率低等技术难题。
The problems of low drilling efficiency and low core recovery due to borehole collapse were solved with pulling in casing while drilling through using combined BHA with casing.
煤矿井下可回收锚杆一般用于煤层巷道，由于锚杆钻孔的变形和塌孔等原因，用普通套筒扳手拆卸锚杆时，因不能给锚杆提供轴向拉力，很难将锚杆拆卸拔出。
It is difficult to pull out the bolt with ordinary socket wrench that can not provide axial tension because of the bolt drilling hole deformation and the collapse of holes.
针对桩位偏移、桩孔倾斜、塌孔等旋挖钻孔混凝土灌注桩常见的质量问题，就其产生的原因进行了分析，并提出相应的预防措施和处理办法。
According to common problems on spiral excavation drilled-pouring pile, including deviation of pile, declivity of hole, slumped hole, it analyzes reasons and puts forward relative prevention measures.
在现场地应力测量过程中发现了岩芯饼裂、钻孔径缩和钻孔破碎塌孔等现象，分析了这些现象的力学机理。
During course of in situ stress measurement, some problems such as core discing, minification and caving of borehole due to horizontal stress are appeared, and their mechanism is studied.
在现场地应力测量过程中发现了岩芯饼裂、钻孔径缩和钻孔破碎塌孔等现象，分析了这些现象的力学机理。
During course of in situ stress measurement, some problems such as core discing, minification and caving of borehole due to horizontal stress are appeared, and their mechanism is studied.
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