1) Forced roof cavingSpan
放顶距
2) zenith distance
顶距
1.
just by pressing a button without the sea horizon to turn to,we should know clearly the relationship between the accuracy of zenith distance observed and the accuracy of a position fixed,the causes of the errors of zenith distance observed,what accuracy of zenith distance observed could be obtained and what accuracy standard should be used.
要在无水天线测天时一按按钮就可定出较精确的船位经纬度,必须弄清天体顶距测量精度对定位精度的影响,弄清顶距测量误差产生的原因,可达到的精度及选用适当的精度标准。
2.
The paper expounds the principle and the method of measuring zenith distance for celestial positioning based on the direction of gravitational force line.
论述了在海上进行天文定位时以重力线作基准直接测定天体顶距的原理和方法。
3) apex distance
顶距
1.
The pipe driving construction method characteristics,pipe material choice,pipe driving force calculation and apex distance determination,working pit and receiving pit selection and size determination were analyzed.
对顶管施工方法工艺的特点、管材选择、顶力计算和顶距确定、工作坑和接收坑选用及尺寸确定等方面进行了分析,并提出了顶管法施工应注意的一些事项,以推广顶管技术的应用。
4) top-collapsing
放顶
1.
The distribution characteristics of initial rock stress in the tectonic stress type mine is analyzed first in the paper,and numerical simulating analysis is used to make analysis of the top-collapsing and failure forms of roof rocks at the western part of Chengchao Iron Mine,which could be theoretical basis to forecast and control the underground roof accidents.
本文首先分析了构造应力型矿山的地应力分布特点,然后对程潮铁矿西区深部开采中,放顶及开采对顶板围岩破坏形式进行了数值模拟,为矿山地压监测和顶板稳定防护提供了理论依据。
2.
Finite element method is used to make an analysis of the underground stress redistribution at the western part of Chengchao Iron Mine during top-collapsing process, and a theoretical basis has been provided to determine correct sequence of caving and forecast and control the underground stress.
采用有限单元法对程潮铁矿西区放顶过程中地压重新分布的规律进行分析,为矿山正确地确定回采顺序和对地压进行预测、管理提供了理论依据。
5) unsupported roof span
控顶距
1.
On the basis of some actual projects,such parameters as wall-rock loose loops and unsupported roof span are provided for Qianling Iron Mine,which can be used as reference and guide for similar projects.
结合工程实际,提出了前岭铁矿的围岩松动圈、掘进控顶距等参数,为类似工程提供借鉴和指导。
6) unsupported roof distance
空顶距
1.
To study the stability of surrounding rock in coal entries,rational unsupported roof distance was obtained ty thin plate theory;which supplied the theoritical base for the surrounding rock control in Daning mine,helped to raise exacavation efficiency and insure safe production.
为了进一步研究全煤巷大断面围岩的稳定性 ,针对大宁矿在掘巷道的情况 ,采用薄板理论分析 ,确定了其巷道掘进的合理空顶距 ,为大宁煤矿煤巷围岩控制提供了理论依据 ;有利于大宁矿进一步发挥掘巷机械的效率 ,保证了安全生
补充资料：综采放顶煤
综采放顶煤：厚煤层煤炭开采技术之一。把原来分层开采的煤炭，一次采完。方法是，在煤层底部按传统方法开采，使上面的煤炭在矿压的作用下，自动落下来。
说明：补充资料仅用于学习参考，请勿用于其它任何用途。
参考词条