open access

https://hdl.handle.net/2115/75097

Field survey on foundation structure of Ohkouzu old movable weir and discussion on causing factor of cavity generated between foundation and ground

日本語

Liquefaction

2016

Japan Society of Civil Engineers

Journal of Japan Society of Civil Engineers, Ser. C (Geosphere Engineering)

72(2)

86-100

This study reports the field survey on ground and foundation structure of the Ohkouzu old movable weir. The geological map around the old movable weir was drawn by boring survey with data in the past references. It indicated the timber piles were point bearing piles which were supported by sandy layers, and the edge of steel sheet piles were driven into clayey layer. They proved the construction work of that time was properly conducted by taking account of geological stratum. Timber piles were shown to be sound and satisfy the required performance in design by both the site loading test and the robust test of piles, although they were constructed about eighty years ago. The cavity was shown to be successively distributed between foundation and ground around the old movable weir and the groundsill. The field survey indicated that the cavity developed in the area where bearing piles or sheet piles were employed in construction. Since the old movable weir experienced 1964 Niigata earthquake and liquefaction damages were widely observed around the old movable weir, the undisturbed soil was sampled from the surface ground below the old movable weir and the liquefaction resistance was investigated by dynamic triaxial test. By the conventional liquefaction analysis, the loose sandy soils was shown to be liquefied or almost liquefied during the Niigata earthquake. Through the case studies in shaking table tests, it was concluded that the cavity below the weir foundation was generated mostly by the ground settlement of loose sandy layers due to earthquake.

学術雑誌論文

Version of Record

2185-6516