“5.12”汶川地震后北川新县城选址地质安全研究

Research on geological security of new Beichuan county seat after "5.12" Wenchuan earthquake

"5.12"汶川特大地震的发震断裂从北川县城穿过,地震时北川县城烈度大于等于10°;地震引发北川县城周围多处山体滑坡、崩塌次生灾害;对北川县城造成了毁灭性破坏,使其成为"5.12"地震中受损最为严重的县城。灾后重建必须把城市安全放在第一位,而城市安全主要取决于地质条件及其安全性。在搜集整理、分析研究大量资料和现场工程地质调查的基础上,首先研究北川县城原地重建的可能性,并提出备选场址比较方案;综合研究原县城驻地、备选场址的地形地貌、地质构造、新构造运动与地震、工程地质、水文地质、不良地质作用与地质灾害等地质安全要素,按照"以人为本、安全第一"的原则,最终推荐安昌东南作为北川新县城灾后重建场址。

The source fault of ＂5.12＂ Wenchuan earthquake passes through Beichuan county seat, and the intensity of earthquake is over 10 degree in Beichuan county seat. There are some slide and collapse caused by the earthquake around Beichuan county seat. The earthquake and incidental geological disaster destroyed Beichuan county seat destructively. Rebuilding of Beiehuan, the safety should be primary concerned. Based on collecting and analyzing existing data, geological investigation, firstly, we should study the feasibility of rebuilding on quondam field of Beichuan county seat, and give the other field for it. Research on the essential of candidate field＇s geomorphology, geological structure, quaternary structure and earthquake, engineering geology, hydrological geology, adverse geologic actions and geological disaster, according to the principle that the most important is the safety, finally, it is made sure that the first field of Beichuan rebuilding county seat is Eastsouthen Anchang town.