root hole

The fracture potential of the root of the access hole is greatly reduced through improving the configuration of access hole.

通过改进工艺孔的形式可以显著降低焊接孔根部发生断裂的可能性。

In addition to the fleetness connects single root, can also use at salvage the homework, search direction or demands the slow the artesian well tool that turn last, and drill the size rat hole use.

除快速接单根外，还可用在打捞作业，找寻方向或需要慢转的钻井工具上，以及钻大小鼠洞用。

Mole cricket is to live in subterranean, the house freely crisscross inside it, very complex, hide in the hole by day, rely on to take crops and vegetable root and tender bine life, arrived evening just runs the activity outside unkennel.

蝼蛄是生活在地下的，它里面的房子纵横交错，十分复杂，白天就躲在洞里，靠吃庄稼和蔬菜的根和嫩茎生活，到了晚间才跑出洞外活动。

Based on careful analysis, it is considered that the root causing the complex accident is the pressure difference between the balance pressure needed and the actual water static pressure down hole.

本文通过分析得出，造成大26井井壁坍塌及其后的井下复杂情况的根本原因是起钻所需平衡压力与实钻井底水静压力之间存在压差。

Spacing charging at blast hole bottom is studied to reduce the seismic, which can make the ratio of vibration reduction to 10-15% and reduce the ratio of boulder and root as accessorial method.

还进一步进行了孔底空气间隔器的降震实验的研究，其降震率达10～15%，作为张沟采场辅助的降震措施，并且有效地降低了大块率和根底的产生。