ABSTRACT
This paper presents results of observation and analysis fo the response of onte of the longest cable-stayed bridges in the world to the Hygoken-nambu (Kobe) eathquake of January 17, 1995. It is determined that intercation of the foundations of the bridge towers with the supporting soil plays a decisive role in the overall structural behavior. The key factor governing the changes of the soil properties at this site is pore water pressure builup, which results in liquefaction of the saturated surface soil layers unde large dynamic loads. Models of the soil and structure are created and initially validated by accurately simulating the system response to a small eathquake. Soil parameters reflecting the pore-water pressure builup in the strong eathquake are determied by advanced nonlinear effective stress analysis, combining the Ramberg-Osgood model of stress-strain dependence with a pore pressure model based on shear work concept. They are utilized to investigate and simulate the interaction of the foundation and the supporting soil using the program SASSI with the flexible volume substructuring approach. The results show a good agreement with the observations and have useful implications to the scientific and engineering practice. (AU)
Subject(s)
Earthquakes , Soil Mechanics , Liquefaction , Seismic Response , Disaster Effects on Buildings , Damage Assessment in Infrastructure , JapanABSTRACT
Presented are development of a new type damper and its application for a long span cable stayed bridge in Japan. Vane type damper was developed and the dynamic characteristics obtained through dynamic loading tests were presented. it was found that the performance of the damper is obtained as demanded, and when applied for a long span cable stayed bridge with a long natural period, the displacement of the bridge caused by earthquake decreases as required.(AU)
Subject(s)
Security Measures , 34661 , Engineering , EarthquakesABSTRACT
The Higashi-Kobe Bridge is a long-span cable-stayed bridge in which the unique feature is that the main girder is supported by towers and piers in such a way that the girder is movable in the longitudinal direction. This supporting method was adopted with the aim of lengthening the fundamental period of the bridge to a relatively longer period. By using this supporting method, the effects of the inertial forces due to the superstructure on the bridge towers and the caisson foundations will be greatly reduced, thereby resulting in a more rational and economical bridge design.(AU)
