光干涉式瓦斯自动警报器的应用技术——用于突出压力快速警报的 CH_4/CO_2检测器

该译文介绍了日本北海道东科计器株式会社最近研制的一种兼作瓦斯突出压力检测用的 CH_4检测器。文中系统地介绍了光干涉仪用作突出压力检测的原理构造、计算公式及井下试验结果。

突出髓核内压力在神经根受压机制中的作用

目的观察腰椎间盘突出症患者突出髓核内压力与神经根受压程度的关系。探讨突出髓核组织的临床意义及手法治疗的机理。方法选取空军总医院收治的腰椎间盘突出症手术患者30例,根据直腿抬高试验分为直腿抬高(+)性组、(-)性组,术中测量患者突出髓核内压力大小、观察突出髓核内压力与直腿抬高高度的关系。结果直腿抬高(+)性组患者突出髓核内压力明显高于(—)性组患者,具有显著意义(P<0.01)。两组患者突出髓核大小无明显差异(P>0.05)。结论1、突出髓核对神经根的压迫与突出髓核内压力有关,突出髓核内压力较大时患者直腿抬高受限,突出髓核内压力较小时直腿抬高不受限。突出髓核对神经根的压迫与突出髓核大小尚未见明显关系。2、椎管对突出髓核组织的容纳的极限与突出髓核内的压力相关,推测手法治疗可以通过降低突出髓核内压力减轻甚至解除神经根受压,达到治疗目的。

煤与瓦斯突出瓦斯射流数值模拟

将煤与瓦斯突出过程的瓦斯突出视为连续射流,应用伯努利方程,建立了瓦斯射流的数学模型,得到了瓦斯突出射流流速和流量表达式,在此基础上考虑突出口压力和突出口直径影响,进行了瓦斯射流的数值模拟,得到了突出压力与突出射流最大速度、突出压力与射流流场分布、突出口直径与突出影响范围间关系规律。模拟结果表明:突出口压力与突出射流最大速度近似呈线性关系,在一定条件下射流流场分布具有甩尾效应,突出口直径越大,其突出影响范围越大。

瓦斯突出分析

从瓦斯压力方面着手,结合生产实例,深入分析了煤与瓦斯压力突出事故发生的原因,介绍了综合防突的技术措施,对确保巷道安全顺利推进积累了宝贵的经验。

Effect of protective coal seam mining and gas extraction on gas transport in a coal seam

A gas–solid coupling model involving coal seam deformation,gas diffusion and seepage,gas adsorption and desorption was built to study the gas transport rule under the effect of protective coal seam mining.The research results indicate:(1) The depressurization effect changes the stress state of an overlying coal seam and causes its permeability to increase,thus gas in the protected coal seam will be desorbed and transported under the effect of a gas pressure gradient,which will cause a decrease in gas pressure.(2) Gas pressure can be further decreased by setting out gas extraction boreholes in the overlying coal seam,which can effectively reduce the coal and gas outburst risk.The research is of important engineering significance for studying the gas transport rule in protected coal seam and providing important reference for controlling coal and gas outbursts in deep mining in China.

Research into comprehensive gas extraction technology of single coal seams with low permeability in the Jiaozuo coal mining area

For a low permeability single coal seam prone to gas outbursts, pre-drainage of gas is difficult and inefficient, seriously restricting the safety and efficiency of production. Radical measures of increasing gas extraction efficiency are pressure relief and infrared antireflection. We have analyzed the effect of mining conditions and the regularity of mine pressure distribution in front of the working face of a major coal mine of the Jiaozuo Industrial （Group） Co. as our test area, studied the width of the depressurization zone in slice mining and analyzed gas efficiency and fast drainage in the advanced stress relaxation zone. On that basis, we further investigated and practiced the exploitation technology of shallow drilling, fan dril- ling and grid shape drilling at the working face. Practice and our results show that the stress relaxation zone is the ideal region for quick and efficient extraction of gas. By means of an integrated extraction technology, the amount of gas emitted into the zone was greatly reduced, while the risk of dangerous outbursts of coal and gas was lowered markedly. This exploration provides a new way to control for gas in working faces of coal mines with low permeability and risk of gas outbursts of single coal seams in the Jiaozuo mining area.

The stress state of geological structure and mining dynamic disaster in Fuxin basin

Further evidences show that most mining dynamic disasters are mainly oc- curred nearby NNE and near SN geological structures.In-situ stress measurement in Fuxin basin shows that the orientation of major compressed stress is near EW.At this stress field,geological structures with deferent strike have deferent stress state and dis- place mode.NNE and near SN geological structures are compressed to thrust and come into being high stress zone.NWW and NEE geological structures are tensile to separate and not prone to being low stress zone.NW structure is intervenient of them.So NEE and near SN structures are easy to occurre mining dynamic disasters and NWW and NEE structures is 'safety' comparatively.The mining dynamic disaster is controlled by stress state of geologic structure,which is determined by its strike.

Coal damage mechanism in the developing process of coal and gas outburst

Based on the damage analysis of elliptical aperture,the mechanism of coal damagein the developing process of coal and gas outburst was researched.The results show thatthe damage to coal by gas is mainly caused by the concentrated tensile stress appearing nearthe endpoint of the pores.Fractures in coal,gas pressure,ground stress and the tensilestrength of the coal matrix are the major controlling factors of this kind of damage.When theground stress releases abruptly and the gas pressure is high,tensile failure will occur aroundthe endpoint of the small pores due to gas pressure,and the coal may be broken up like powder;this is called pulverization.Otherwise,when the gas pressure is low,the tensile stress canonly occur around the endpoint of the large pores and fractures due to gas pressure,the fracturesin coal extend and link together,the fracture extension direction is statistically perpendicularto the direction of the minor principal stress.This kind of damage is shown as the stratifiedspall around the outburst hole.

不同突出口径下冲击波穿越反向风门孔洞传播规律试验研究

为了研究突出口径对冲击波穿越反向风门孔洞(以风门底坎为例)传播规律的影响,搭建了煤与瓦斯突出模拟试验装置。基于物理试验,研究了不同突出压力、不同突出口径条件下冲击波在巷道内穿越反向风门孔洞的传播规律。结果表明:突出发生后冲击波以极快的速度在巷道内传播,且主要沿直巷道传播;冲击波超压变化并非一次完成,完成时间在0.6 s内;受反向风门阻滞作用,少部分冲击波穿越风门孔洞继续向前传播,其余部分与风门碰撞后发生反射,风门底坎尺寸越小,阻滞作用越显著,合理制定风门底坎尺寸能够遏止突出次生事故的发生;不同突出压力、突出口径下,冲击波超压变化趋势相似,冲击波超压峰值随突出压力、突出口径的增大而增大;突出口径越小,冲击波衰减速度越慢,超压曲线越平缓,超压变化持续时间越长。