The pre-drainage technology with dense boreholes is a preventive measure for the coal and gas outburst.
密集钻孔预抽瓦斯技术是一种防止煤与瓦斯突出的措施,钻孔在煤层中所形成的应力分布、透气性规律和瓦斯的流动过程是极其复杂的问题,本文主要采用实验室试验和数值试验进行了系统研究,即采用平面应变模型,揭示密集钻孔的透气性、应力分布、塑性区和卸压区的范围、煤层瓦斯压力变化、预抽半径和钻孔瓦斯流量等问题。
Model Experiment of Gas Permeability Distribution Rule around Dense Boreholes
密集钻孔周围透气性分布规律的模型实验
Laboratory and Numerical Test Studies of Gas Pre-drainage with Dense Boreholes in Outburst Coal Seam;
突出煤层密集钻孔瓦斯预抽实验室与数值试验研究
Experimental Investigation of Three-phase Foam Sealing Liquid for Gas Pressure Determination Borehole
测压钻孔三相泡沫密封液的试验研究
Penetration Mechanism of DTH Percussion Compact Drilling and Experimental Research on Compact Bit;
潜孔锤冲击挤密钻进机理及挤密钻头的设计与实验研究
A New Algorithm for Mineral Storage Calculation Based on Voronoi Diagram of Point-sets of Drill Holes;
基于钻孔点集Voronoi图的矿产储量新算法
Effect of Drilling Fluid Density on Neutron Porosity in Underbalanced Drilling
欠平衡钻井条件下钻井液的密度对中子孔隙度测井的影响
Field tests on pre-bored compaction lime-soil pile(down-hole dynamic compaction method) to improve serious collapsible loess
钻孔挤密桩处理强湿陷性黄土地基试验研究
Design of Composite Foundation with Drilling Ram-expanded Piles in Collapsed Loess
湿陷性黄土钻孔夯扩挤密桩复合地基设计
tap(ping) drill
螺丝孔钻，螺丝底孔钻
The sorker was drilling.
此工人在用钻孔机钻孔。
dirll ,ultrasonic, for use with minerals or with ceramic substances for integrated circuits
超声钻孔机,用于矿物体或集成电路的陶瓷基片
Numerical simulation of small pillar stress concentration areas borehole pressure relief effect
小煤柱应力集中区钻孔卸压效果的数值模拟
Simulation and analysis of three-dimensional flow field in punched apron compact spinning
钻孔皮圈集聚纺纱系统三维流场的模拟与分析
Any of numerous hand tools for boring holes.
钻孔工具，手钻钻孔用的手持工具
kelly for well-drilling machiens
旋转钻孔,钻井机用
A tool used for drilling.
钻头用于钻孔的工具
"at no time should hole be made in top of control panel, unless proper sealing devices are utilized. "
除非采用适当的密封设施,否则绝对不要在控制面板上钻孔。
The Application of Directional Drilling and Towing High-Density Polyethylene(HDPE) Pipe in Municipal Pipeline Engineering;
定向钻孔牵引高密度聚乙烯管材在市政管道工程中的应用