含气多孔介质卸压层裂的间隔特征——突出的前兆
SECTIONAL FRACTURING OF POROUS MEDIA CONTAINING PRESSURIZED GAS UPON UNLOADING —— FOREWARNING INFORMATION OF OUTBURST 1)
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摘要: 含气多孔介质在卸压下的拉伸破坏有两种模式———层裂和突出.达到或超过临界破坏条件,引发骨架层裂破坏;达到或超过更强一些的临界突出条件,则引发突出.从采煤实践中逐次掘进的长过程看,层裂是已达破坏条件而未到突出条件的情况,进一步发展可能引发突出.实验表明层裂显现规律的间隔特征,因而与层裂相关的瓦斯浓度变化和地音信息可以认作是突出的前兆.如果在内部形成破坏区,渗流场与应力场的耦合有可能导致延时突出、石门自揭(岩石巷道掘进过程中临近煤层时岩体失稳破坏)等一类现象,显现强的时效特征,其时效是由渗流过程控制的.Abstract: A series of one dimensional simulation experiments (coal shock tube) showed that two kinds of damage, fracturing or outburst, could take place, when a porous medium containing pressurized gas and bearing compressive stress was suddenly unloaded. The critical condition of outburst is stronger than that of damage. In other words, outburst is a strong kind of damage. Therefore, there exists the case in which the damage condition is met while the outburst condition has not yet been met. Experiments showed a ...
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Keywords:
- outburst /
- fracturing /
- porous medium
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