An earthquake with a moment magnitude of 7.8 occurred at 11:56 NST (local time) on 25 April 2015, in the central part of Nepal (Gorkha). First damage surveys were conducted at the affected area during 26 May to 21 July three times by the team of NIED. This paper outlines the findings of the surveys on the various spects of the earthquake disaster in the Kathmandu Valley. Some of the observations are that the main damage was to masonry buildings especially with mud mortar, but limited to RC buildings, and the historical buildings with renovation showed smaller damage. Thus, low cost retrofitting method will be necessary for mainly in suburb housings rich in masonry buildings with mud mortar. According to the comparison with the past risk assessment project results (JICA, 2002), these were found that the effects by the 2015 Gorkha earthquake were less than those due to the 1934 Bihar-Nepal Earthquake, and the similar features were found in both the 1833 Earthquake and the 2015 Gorkha Earthquake. Primarily, the first survey was to collect timely raw information on the damage to buildings and to confirm the availability of data and their sources for subsequent surveys. The motivation for the thread survey was to obtain ground truth data to calibrate. These may help the future earthquake disaster mitigation efforts.
We propose quality assurance procedures of automatically constructed models for seismic response analysis. In these procedures, models of different fidelity are used, and the quality of a higher fidelity model is examined by comparing its response with a lower fidelity model. A key issue is the consistency of the models of different fidelity, and the meta-modeling theory is used to guarantee the consistency. As an illustrative example, models of different fidelity are automatically constructed for a bridge structure, and it is shown that the developed procedures are applicable to them. The quality of the automated solid element model that is of highest fidelity is examined.
格子メッシュ等を用いない数値解析手法のひとつにMaterial Point Method（MPM）と呼ばれる手法がある．本手法は境界条件等を設定する際に曖昧な定義が無く，大変形問題への適用も容易であることから，近年，地盤分野において積極的に適用されている．しかしながら，動的解析を実施した場合，得られる弾性エネルギーが振動する等の問題が指摘されており，今後，地震応答解析等への適用を行う場合，大きな欠陥となるため，その振動を抑制する新たな手法の開発が求められている．そこで，本研究では，MPMで定義される粒子のひずみ増分値を移動最小自乗法によって補間することで，弾性エネルギーの振動を抑える手法を提案する。本論文では，いくつかの既存手法との比較解析例を示すことによって本手法の妥当性について検討する．