洪水氾濫による家屋流失の危険度評価

Abstract

In Janan, there are many wooden houses in flood hazardous zone. It seems that the woodenhouses are comparatively easy to be swept away due to its weak base structures. By carryingout the model experiments on hydraulic force acting on the house, it was found that therewere linear relations between the moment M arround the bottom of the pillar and the hydraulicforce factor u2A by taking water depht h as a parameter. Then applying the maximumestimated momental value of resistance to collapse derived from a real scale wooden housetest to this relation, we obtained the curves which present the critical combinations of thedepth and velocity in the flood flow which will destroy the houses. So far river flowing datashowed rather good agreements to these critical lines, whereas, tsunami data did not. Themain reason to this discrepancy was attributed to the difference of mechanism of externalforce between flow and wave.Resistance of a window glass against hydrodynamic pressure were examined and the riskof the glass window failure which may result in a severe damage to the house was discu-ssed. Moreover, in relation to hydraulic force, effects of existance of the other houses withvarious arrangement were also examined.