地震保険研究８

自治体の地震被害想定における被害予測手法の調査

平成１８年７月
損害保険料率算出機構

はじめに
平成７年の阪神・淡路大震災を契機として地震防災の重要性が再認識され、全国の多くの自治体で地域防災計画策定の基礎資料となる地震被害想定の実施・見直しが行われています。各自治体では、一般市民の地震リスクに対する関心や意識の高まりに応える形で想定結果や内容を積極的に公表するようになってきました。
各自治体の調査報告書をみると、阪神・淡路大震災やそれ以降の地震災害に関する調査研究の成果を積極的に取り入れ、被害予測手法や想定地震などの見直しに取り組んでいることが分かります。特に近年は、内閣府中央防災会議により東海地震や東南海・南海地震、首都直下地震等の被害想定が次々に実施・公表され、社会的にも大きな反響を呼んでおり、自治体の中には国の検討成果を被害想定の中に取り入れる事例がみられます。
本資料集は、被害想定を公表している各自治体から入手した調査報告書等に基づき、被害予測手法を中心に整理したものです。作成にあたっては、各手法を見やすく、系統的に整理することを心掛け、出来るだけ図表も取り入れました。本書が防災や保険など災害に係る分野において有益な資料となれば幸いです。
終わりに、ご多忙のところ被害想定資料の収集にご協力いただきました地方自治体の防災担当者の皆様に厚く御礼申し上げます。

平成１８年７月
損害保険料率算出機構

目
第Ⅰ章

次
概要 ····························································

1

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

3

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

3

１－２．地震被害想定調査の歴史·····································

4２．本資料の概要 ······················································

6２－１．参考とした被害想定資料·····································

6２－２．本資料の構成···············································

6３．本資料の見方 ······················································

9第Ⅱ章

ハザード予測手法の整理 ········································ 11１．地震動の予測 ······················································ 13１－１．工学的基盤面の地震動······································· 15
１－２．地表面の地震動············································· 30１－３．震度（計測震度）の計算····································· 35
２．液状化危険度の予測 ················································ 39２－１．地盤データを用いる手法····································· 40
２－２．地形データを用いる手法····································· 49
３．地盤崩壊危険性の予測 ·············································· 51
３－１．斜面崩壊危険度············································· 51
３－２．宅地造成地の被災危険度····································· 60
４．津波の予測 ························································ 63
４－１．伝播計算・遡上計算········································· 64

第Ⅲ章

被害予測手法の整理 ············································· 69

１．建物被害の予測 ···················································· 71
１－１．ゆれによる建物被害（木造）································· 73
１－２．ゆれによる建物被害（非木造）······························· 97
１－３．液状化による建物被害······································· 117
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 ············ 127
１－５．地盤崩壊による建物被害····································· 128
１－６．ブロック塀等の被害········································· 132
１－７．津波による建物被害········································· 134
２．地震火災による建物被害の予測 ······································ 135
２－１．出火件数（炎上出火件数）··································· 137

２－２．延焼出火件数··············································· 148
２－３．焼失建物数················································· 159
３．人的被害の予測 ···················································· 171
３－１．死傷者数··················································· 171
３－２．要救出者数················································· 189
３－３．避難者数等················································· 190
３－４．帰宅困難者数··············································· 194
４．ライフライン被害の予測 ············································ 195
４－１．電力の被害・復旧··········································· 196
４－２．通信の被害・復旧··········································· 205
４－３．上水道の被害・復旧········································· 209
４－４．下水道の被害・復旧········································· 220
４－５．都市ガスの被害・復旧······································· 224
４－６．プロパンガス（LPG）の被害・復旧 ··························· 230
５．交通・輸送施設被害の予測 ·········································· 231
５－１．道路の被害················································· 231
５－２．鉄道の被害················································· 249
５－３．港湾・漁港の被害··········································· 252
６．土木構造物被害の予測 ·············································· 257
６－１．河川堤防・海岸堤防の被害··································· 257
６－２．ため池の被害··············································· 262

第Ⅳ章

各自治体の被害想定の概要 ······································ 265

１．想定項目 ·························································· 267
２．被害予測単位 ······················································ 271
３．想定地震および被害予測結果の概要 ·································· 273

参考文献