James M. Kelly 
Earthquake-Resistant Design with Rubber 

My involvement in the use of natural rubber as a method for the protec- 1976. At that time, tion of buildings against earthquake attack began in I was working on the development of energy-dissipating devices for the same purpose and had developed and tested a device that was even- tually used in a stepping-bridge structure, this being a form of partial isolation. It became clear to me that in order to use these energy devices for the earthquake protection of buildings, it would be best to combine them with an isolation system which would give them the large displace- ments needed to develop sufficient hysteresis. At this appropriate point in time, I was approached by Dr. C. J. Derham, then of the Malaysian Rubber Producers’ Research Association (MRPRA), who asked if I was interested in looking at the possibility of conducting shaking table tests at the Earthquake Simulator Laboratory to see to what extent natural rubber bearings could be used to protect buildings from earthquakes. Very soon after this meeting, we were able to do such a test using a 20-ton model and hand-made isolators. The eady tests were very promising. Accordingly, a further set of tests was done with a more realistic five- storey model weighing 40 tons with bearings that were commercially made. In both of the test series, the isolators were used both alone and with a number of different types of energy-dissipating devices to en- hance damping.