hard formation bit,hard formation cutting head

6 connecting methods between green area and hardstand were presented and propositions were offered.

介绍了园林绿地与硬地铺装之间的6种交接方式,提出了合理利用地形和合理选用材料以协调两者之间的关系。

Parameter selection for diamond drilling in hard rocks;

坚硬地层金刚石钻进参数的选择

Design of PDC bit for hard formation;

硬地层PDC钻头设计的探讨

PDC bits are generally inadaptable for drilling hard formation,especially for the gravel layer with high compressive strength and abrasion.

PDC钻头不适宜钻硬地层,尤其是高强度、高研磨性的砾石层,因为在极其恶劣的工作条件下,PDC齿的冲击破损严重,热磨损及磨料磨损往往同时存在,齿的磨损速度快,钻头的工作寿命急剧缩短。

Improving the drilling rate of hard formation is always a problem in the world.

为了解决提高硬地层钻井速度的钻井难题,以粒子冲击钻井系统的整个工艺流程为依据,论述了粒子冲击钻井技术的优点和缺点,阐述了其破岩机理。

For the research on characters of cemented soil of SMW(soil mixing wall) technology in medium-hard strata is shortage,so the application in medium-hard soil is restrained.

针对SMW工法缺乏对中硬地层的水泥土性能研究,利用首例北京地区在中硬地层中地铁基坑工程采用SMW工法搅拌后的水泥土,进行了三轴压缩试验。