CONSIDERATIONS ON CLASSIFICATIONS AND COUNTERMEASURES OF FACE'S UNSTABLE PHENOMENON

Abstract

In the mountain tunnel, the face stability is necessary until the support will confine the ground. However there were considerably many cases which fall into the accident construction by face's collapse. An unstable phenomenon including face's collapse is an important problem in the tunnel construction, it causes serious influence to the safety, delivery and cost etc. of the tunnel construction. We try to classify the unstable phenomenon experienced by the many tunnel constructions in our country, and consider the unstable phenomenon. We will propose the new countermeasure of the face stabilization by considering the ground conditions which trigger unstable face.