At present,TSP,geological radar are mainly used to construct the advance forecast,it have a poorer prediction effect of groundwater prediction.To find the method to solve the prediction of the underground water in tunnel,the joint exploration of MTEM and the DC detection was carried out in the tunnel.According to the unnel and underground construction environment and the detection of the target body and theoretical analysis,in the construction process,a slight improvement was carry out.For example:in MTEM,in order to facilitate scanning in a certain angle,a special bracket was made;In DC detection,in order to improve the signal to noise ratio,based on the principle that the apparent resistivity value of the near field of the low frequency AC electromagnetic field is equal to the DC resistivity value,using 15 Hz low frequency AC power supply.After data processing,it can obtained better geological effect.Comparison of these two methods,the MTEM is more suitable for the prediction of the groundwater in the tunnel,because of its construction is not ground and directional well,the construction efficiency is relatively high,processing results for the sector area,the interpretation of a larger.%针对隧道超前预报TSP、地质雷达等方法在超前预报构造、防治地下水方面效果欠佳等问题,为了寻求解决隧道地下水超前预报的方法,在隧道开展了矿井瞬变电磁超前探测以及矿井三点-三极超前探测的综合勘探,根据隧道与煤矿井下施工环境以及探测目标体的不同,通过理论分析,在施工工艺方面稍作了改良,如矿井瞬变电磁法,专门定做了发射线框的支架,方便按照一定角度进行扫描;矿井三点-三极超前探施工时,为了提高信噪比,根据低频交流电磁场的近区场的视电阻率值与直流电法视电阻率值相等的原理,使用了15 Hz低频交流供电.经过数据处理,分别取得了较好的地质效果.比较2种探测方法相后,认为矿井瞬变电磁法更适于隧道地下水的超前预报,因为其定向性好,施工效率相对较高,处理成果为扇形区域,更加直观.
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