地震保険研究 37

国・自治体の地震被害想定における被害予測手法の調査（2021 年度調査）

令和 4 年 9 月

損害保険料率算出機構

はじめに国や自治体で実施している地震被害想定およびその予測手法は、地震被害や調査研究による新たな知見を随時反映し、更新・公表されています。予測手法は地域の災害特性を考慮して検討されており、それらを体系的に整理することは今後のリスク評価手法を検討する上で有益 で す 。 そ の た め 、 当 機 構 で は 平 成 10 年 （ 地 震 保 険 調 査 報 告 28 ） 、 平成 18 年 （ 地 震 保 険 研 究 8 ） 、 平 成 25 年 （ 地 震 保 険 研 究 27 ） に 予 測 手 法 を調査・整理し報告書としてまとめました。
平 成 23年 の 東 北 地 方 太 平 洋 沖 地 震 を 受 け て 、 国 や 多 く の 自 治 体 で 地震被害想定の見直しが行われました。そこで、最新の被害想定における予測手法を把握する目的で、資料の調査・整理を実施しました。本
報告書は、その結果をまとめたものです。
本書が、防災や保険などの災害にかかわる分野において有益な資料となれば幸いです。

令和４年９月
損害保険料率算出機構

目
第Ⅰ章

次

概要 ····························································

1１．地震被害の想定 ····················································

1１－１．地震被害想定調査の流れ ·····································

1１－２．地震被害想定調査の歴史 ·····································

2２．本資料の概要 ······················································

5２－１．参考とした被害想定資料 ·····································

5２－２．本資料の構成 ···············································

5２－３．本資料の見方 ···············································

7

ハザード予測手法の整理 ········································

9１．地震動の予測 ······················································

9１－１．工学的基盤面の地震動 ·······································

9第Ⅱ章

１－２．地表面の地震動 ············································· 14
１－３．震度（計測震度）の計算 ····································· 19
２．液状化危険度の予測 ················································ 20２－１．地盤データを用いる手法 ····································· 20２－２．地形・地盤分類データを用いる手法··························· 24２－３．液状化に伴う地盤沈下量の予測······························· 26３．地盤崩壊危険性の予測 ·············································· 27３－１．斜面崩壊危険度 ············································· 27
３－２．宅地造成地の被災危険度 ····································· 33
４．津波の予測 ························································ 35

第Ⅲ章

被害予測手法の整理 ············································· 37

１．建物被害の予測 ···················································· 37
１－１．ゆれによる建物被害（木造） ································· 37
１－２．ゆれによる建物被害（非木造）······························· 48１－３．液状化による建物被害 ········································ 52
１－４．ゆれによる建物被害と液状化による建物被害の関係 ············ 57
１－５．地盤崩壊による建物被害 ····································· 58
１－６．ブロック塀等の被害 ········································· 61
１－７．津波による建物被害 ········································· 63
２．地震火災による建物被害の予測 ······································ 66
２－１．出火件数（炎上出火件数） ··································· 66

２－２．延焼出火件数 ··············································· 75
２－３．焼失建物数 ················································· 78
３．人的被害の予測 ···················································· 84
３－１．死傷者数 ··················································· 84
３－２．要救出者数 ················································· 100
３－３．避難者数等 ················································· 102
３－４．帰宅困難者数 ··············································· 106
４．ライフライン被害の予測 ············································ 109
４－１．電力の被害・復旧 ··········································· 109
４－２．通信の被害・復旧 ··········································· 118
４－３．上水道の被害・復旧 ········································· 123
４－４．下水道の被害・復旧 ········································· 131
４－５．都市ガスの被害・復旧 ······································· 137
４－６．プロパンガス（LPG）の被害・復旧···························· 141
５．交通・輸送施設被害の予測 ·········································· 142
５－１．道路の被害 ················································· 142
５－２．鉄道の被害 ················································· 149
５－３．港湾・漁港の被害 ··········································· 153
６．土木構造物被害の予測 ·············································· 154
６－１．河川堤防・海岸堤防の被害 ··································· 154
６－２．ため池堤防の被害 ··········································· 156

参考文献