SURFACE SHAPE MEASUREMENT AND EVALUATION OF MECHANICAL STABILITY BY DEM SIMULATION FOR DAMAGED TRADITIONAL STONEWALLS

Abstract

Kumamoto Castle has constructed about 400 years ago, and now the Cultural Affairs Agency
of Japan treats it as an important historical spot. The 2016 Kumamoto Earthquake was damaged a lot of stone
walls of this castle. Authors continue to investigate the deformation of unstable stonewalls by high accuracy
laser module for measuring distance. And these stonewalls should be monitored continuously for evaluation of
mechanical stability, so we developed and established the wireless network system for measuring the changing
angle of some stonewalls surface in this castle. When installing this system in the future, the results of shape
measurement of the surface of these stone walls will be important in identifying the locations to be installed
and setting priorities. The authors also carried out making a simulation model and calculation for evaluation of
stonewalls stability by the distinct element method under the several conditions of stonewall shape and
interface of materials. The failure area of stone walls and backfill are estimated by these results of DEM
simulation, and it is discussed that these areas should be reinforced under the repair of damaged stonewalls.