The application of base isolation systems to structures provides an excellent alternative for seismic protection. Many base isolation systems are available but an economic and effective system has not been developed for residential structures. The purpose of the proposed research is to identify and evaluate the physical characteristics that are required to make a "sand-joint" isolation scheme effective and practicable for a seismic design of masonry dwellings. The basic idea of the sand-joint is to form a relatively weak frictional plane at the base of a masonry wall by separating the wall from the foundation with a thin layer of sand. This joint isolates the structure from strong ground motion in much the same manner as do more sophisticated base isolation mechanisms currently being implemented in larger structures. Although the sand-joint approach already has been introduced in the Peoples Republic of China (PRC) on a very limited basis, the optimal characteristics of this mechanism have not yet been determined.
