Abstract
The telecommunication conduits are needed to protect underground cables from damages due to earthquakes.However, the seismic capacity is being degraded due to the superannuated conduits that were constructed during the high-growth economic period.To sustain the reliability of the conduits efficiently through maintenance is the current challenge.
This paper presents the reproductive experiments of the damage of underground telecommunication cable at the time of earthquakes in order to clarify the limit of opticalfiber cable restoration. By modeling the seismic damage of undeground conduits for the experiment, we could confirm that optical fiber cables are damaged not only at conduit fractures but also manholes which they are pulled into. When the characteristics of optical fiber cables on the seismic disaster were verified by experiment, it is shown that not only tension force but also bending angles causes the fault of transmission. The relation between the tension and the bending angles that the cable suffers damage is clarified. This result can be used for the rational measures to prevent the damage of the telcommunication service.
