Physical Simulation of Tunnel Advance Geological Prediction by Transient Electromagnetic Method
（1 Norendar International Ltd. of China North Industries Group Corporation Limited, Shijiazhuang 050011; 2 School of Earth Science and Engineering, Hebei University of Engineering, Handan 056038）
Abstract：
The model experiment is designed based on the physical simulation similarity criterion, and the total sur? rounding space, homogeneous medium, tunnel space, anonymous body and metal disturbance mass are simulated by water channel, brine, plastic slot, copper plate and iron weight, focusing on the influence of tunnel space, metal disturbance mass and anomalous body itself on tunnel advance geological prediction by transient electromagnetic method.The experiment results show that tunnel space has slight effect on secondary electromagnetic response value and barely little effect on decay rate of secondary electromagnetic response; the prediction results will be significantly affected due to presence of metal disturbance mass, which results in increase of induced electromotive force and the presence pseudomorphism of low resistance anomalous body; the induced electromotive force exponentially decays with an increase of distance between anomalous body and pick-up coil during the physical simulation of anomalous bodies in different positions; the feasibility of application of transient electromagnetic method in tunnel advance geological prediction is verified.
2019, Vol. 56 