In Japan, a lot of underground structures has been constructed and they are in service in spite of complex and poor geological conditions. On the other hand, Japan is famous for the big earthquakes resulting a huge national loss, thus the aseismic design to prevent the severe damage of structures is very important. Though many buildings and structures are designed considering earthquakes, the aseismic design of structures constructed in deep underground has not been well discussed up to now. In this paper, the historical background of aseismic design is reviewed and typical seismic damages of rock tunnels are presented. And the present situation of static and dynamic design for underground structures ranging from the cut and cover tunnels in the shallow underground to the rock tunnels in deep rock formation is presented. Then problems to establish a practical method of aseismic design for the rock tunnels is discussed.
Underground structures are utilized for various purpose and playing an important role as a social infrastructure. They are classified into the following three types according to the construction method, namely cut and cover tunnel, shield tunnel and drill and blast (rock) tunnel (including caverns). Typical shape and scale of these structures are shown in Figure 1.
As Japan is famous for big earthquakes resulting a huge national loss, thus the aseismic design is very important for every kind of structures. Today we have a strict regulation concerning to the aseismic design of buildings and a various kind of civil structures. It has to have a long way to result in this situation and even now we are repeating "Lesson and Learn".
According to the Japanese standard for tunneling of Japanese Society of Civil Engineering (JSCE), and other aseismic design related documents, the history of aseismic design for buildings and underground structures can be summarized as follows.