耐震設計に用いるジオグリッドの引張強さに関する一考察

Abstract

Generally, as for the design tensile strength of geogrid used as reinforcement material, tensile strength is decided considering creep characteristic. It is also known that the tensile characteristic of geogrid made of polymer material depends on the elongation rate showing large tensile strength under high elongation rate. On the other hand, some methods of evaluating the design tensile strength for a dynamic design are proposed by some organizations. However, those methods aren't yet standardized. Realistically in such reason, the design tensile strength for the static design is also used for the dynamic design. When thinking of the design strength of geogrid in case of dynamic loading, tensile characteristics after creep phenomenon occurs by static load are a problem. Its characteristics depend on static load to make creep phenomenon occur, continuing time, elongation rate which acts on geogrid in case of the earthquake and so on. In this research, the tensile characteristics of geogrid after a creep phenomenon by the static load are tested. The techniques of the data gathering and evaluation, which is the basis about the setting of dynamic design tensile strength, are considered.