多场前兆信息辨识粉砂岩巷道突水模拟实验研究

Experimental study on sandstone tunnel water inrush precursor information identification of multi-fields

采用高速照相机、红外热像仪和声发射系统对巷道掘进面突水过程进行监测,总结加载过程中可见光图像、红外辐射温度以及声发射参数变化规律,寻找粉砂岩巷道突水的前兆信息。研究结果显示,突水发生前,巷道掘进面的渗水面积因渗水量增大而出现扩大情况。随载荷的增加,突水呈现2种模式,即"渐变型"和"突增型"。2种模式的突水发生前均存在多场信息变化的前兆。"渐变型"突水发生前红外最低温曲线呈现"降转升"波动,声发射出现大量低能率事件。"突增型"突水发生前红外最低温曲线为"突升转平静"变化,声发射表现为大量高能率事件。经统计分析,3种监测手段对突水前兆响应顺序为:红外>可见光>声发射。由于巷道突水的复杂性,建议采用多场联合监测方法,为突水监测提供更可靠的预警信息。

The water inrush process of tunnel face has been monitored by using high speed camera, in- frared thermography and acoustic emission system. Characteristics of evolution law of visible light im- age, infrared and acoustic emission in the loading process have been studied and the precursory infor- mation of siltstone water inrush can also be found. The experimental results have shown that in the early stage of water inrush, the area of water seepage in water inrush position of roadway face has increased with the increase seepage quantity. Two kinds of water change have been presented during water inrush： one is ＂gradient type＂ and the other is ＂spurt type＂. The parameters of multi-field information change have appeared prior to the occurrence of these two kinds of water inrush. The evolution process of in- frared and acoustic emission is closely related to the mode of water inrush. The lowest temperature curve of infrared has shown ＂drop to rise＂ fluctuation, and large number of low energy rate events have appeared within acoustic emission before the water inrush of ＂gradient type＂. However, the lowest tem- perature curve of infrared has shown the trend of ＂uprush to calm＂, and a great deal of high energy rate events have come out within the acoustic emission before the water inrush of ＂spurt type＂. Depending on the results of statistical analysis, it can be concluded that the sensitivity to water inrush of three monitoring methods is in a declining order from infrared, to visible image, and acoustic emissions. Because of the complexity of tunnel water inrush, it is recommended that multiple parameters of moni- toring methods should be united to provide more reliable early warning information for the monitoring of water inrush.