Coalface of Daizhuang Coalmine, the authors believe that the roof in lower seam will form the "block-bulk-beam" structure easy to fall after the mining of top ultra-close seam.
通过对岱庄煤矿4300采区工作面的顶板结构分析，得出了上部极近距离煤层开采后，下部煤层顶板形成极易漏冒的“块体-散体-梁”结构。
Today during the mining process in contiguous seams, there are many factors leading to hidden danger, such as: the top board being tortured during the exploitation of the lower seam;
目前，我国矿山在极近距煤层开采过程中，下部煤层开采时，顶板遭受损伤，工作面及巷道顶板易于出现冒顶、漏顶现象，严重时造成支架埋压；
If you are impatient and want a quick preview of how simple a Seam application is, you can have a look at the hello world example described lower in this article.
如果没有耐心，或者想要快速预览，一个Seam到底有多简单，你可以现看看本文描述的hello world一例。
But with the same length of straight seam pipe than the weld length of 30 ~ 100%, and lower production rate.
但是与相同长度的直缝管相比，焊缝长度增加30 ~ 100%，而且生产速度较低。
The steep inclined seam is a difficult mining seam with a poor safety condition, a poor support stability, a lower mechanization and lower mining rate.
急倾斜煤层属难采煤层，具有安全状况差、支架稳定性差、机械化程度低、回采效率低等问题。
The Middle and Lower Jurassic with thick coal seam is widely distributed in Northwest China.
西北地区中、下侏罗统煤层广布，厚度较大；
In underground coal mines, Rayleigh wave method was used to detect lower coal seam and structures ahead roadways and produced satisfactory results.
在井下用瑞利波方法探测下部煤层、超前探测煤巷、岩巷前方的构造，取得了满意的效果。
Numerical simulation software FLAC2D is used to simulate the failure mechanism of slender coal pillars (which are of much lower width to height ratios) during high wall mining of thick seam.
对特厚煤层条件下采用螺旋钻机开采细长窄煤柱的破坏过程进行了数值模拟。
The firm decommissioned the remaining two coal seam gas (CSG) wells and the land rehabilitated at costs lower than budgeted.
公司名下的两口煤层气油井已经停产，并且土地复原费用低于公司预算。
Thus the nozzle attachment is always positioned with a defined force on the lower web that is to be heat sealed, resulting in a seam of consistently high quality.
由此，喷嘴附件一直以确定的力靠置于在下面待焊接的膜上，而能够产生稳定的、良好的接缝质量。
Thus the nozzle attachment is always positioned with a defined force on the lower web that is to be heat sealed, resulting in a seam of consistently high quality.
由此，喷嘴附件一直以确定的力靠置于在下面待焊接的膜上，而能够产生稳定的、良好的接缝质量。
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