On-line pseudo-dynamic response test for evaluating seismic isolation effect by tire chips on response of saturated sand deposits

The volume of waste tires is increasing every year and it has become a major environmental problem. In the use as a heat source which is the mainstream of recycling, there are problems, such as waste of rubber resources and generating of carbon dioxide. Therefore, increasing attention has been paid in recent years on the technology of using scrap tire derived recycled products (tire shreds and tire chips) in construction. With characteristics such as lightweight, compressible, permeable, durable and thermally insulating, this material has a myriad of applications in civil engineering. This research attempts to exploit the potentials of tire chips as a tool to attenuate the earthquake loading propagating through the foundation soils. Online testing is a method of feeding soil response characteristics directly from soil samples into a modeling algorithm. The effects of the layer thickness of tire chips, configuration and degree of mixing between tire chips and sand on the earthquake characteristics of alternating layers of sand and tire chips have been investigated. As a result it was confirmed that tire chip layers attenuate the motions of sand layers for short period vibrations increasing strain in overlying sand layers. Moreover, tire chip layers which were closer to the bottom or greater thickness tended to decrease the surface accelerations.