大水深防波堤の安定性について

Abstract

The South Breakwater of the New Nagasaki Fishing Port, damaged due totyphoon in 1987, has been restored during fiscal 1988. This composite breakwaterhas been constructed with instruments installed to monitor settlements and lateraldisplacements of the breakwater foundation.This paper is concerned with the coupled stress-flow analysis for this site usingthe elasto-viscoplastic finite element method. The finite element analysis isperformed with the emphasis on the actual process of construction, such as rubblemound formation, setting the caisson wall and so forth. As the foundation justbeneath the caisson wall are treated with densely compacted sand (SCP), both thesettlement and lateral displacement are controlled during the breakwaterconstruction. Calculated performance can qualitatively describe the settlement andthe lateral displacement monitored, and also ascertain the stability of the restoredbreakwater. The simplified simulation for caisson wall sliding and failure subjectedto wave impact is performed, assuming the distributed wave stress applied in frontof the caisson wall.