汶川地震地表破裂影响带调查与建筑场地避让宽度探讨
|
摘要
5.12汶川Ms8.0级地震沿龙门山中央断裂带形成长度约270km的地表破裂带,破裂带垂直和水平位移一般为1.0～5.0m,最大可达9.8m。在地表破裂带附近,建筑物破坏严重。笔者系统调查了龙门山中央断裂带地表破裂的垂直和水平位移以及地震地表破裂影响带宽度,并采用物探测试方法对部分影响带宽度进行了验证。统计结果表明,汶川地震地表破裂影响带宽度主要集中在16～60m,影响带宽度(D)与垂直位移(H)具有较好的线性关系,即D=10.11H+16.0。对于逆冲性质为主的地震地表破裂而言,上盘影响带宽度与下盘的比值一般为3:1～2:1,据此可确定地表破裂带上、下盘的避让带宽度。笔者根据现场调查并借鉴国外经验提出,上盘避让宽度下限一般不应低于15m,下盘避让宽度下限不应低于10m。本项研究对于汶川地震灾后重建场地选址具有重要的实际意义。
The Wenchuan earthquake occurred along the Longmenshan thrust fault belt.The Longmenshan central fault is the earthquake causing fault.The total rupture length along the Longmenshan central fault caused by the Wenchuan earthquake is about 270 km and the average vertical and horizontal displacement range from 1.0 m to 5.0 m,up to about 9.8 m in local parts.A lot of buildings were broken in the area where the ruptures passed through.In this paper,the authors report the investigation results of the vertical and horizontal displacements,as well as the width of rupture influenced zones which were confirmed by the geophysical survey methods,in different locations along the Longmenshan central fault.It is indicated that the influenced scopes of the earthquake ruptures mainly range from16 m to 60 m,and the relationship between the influenced scopes(D)and the vertical displacement(H)is obvious linearity,which can be expressed as:D=10.11H+16.0.Due to the Longmenshan central fault being a mainly thrusting fault,the influenced zone ratio between the hanging wall side and the foot wall side is generally from 3:1 to 2:1,which can help to determinate the safe distance for building site.On the basis of field investigation and using overseas experience for reference,the limit of the safe distance on the hanging wall side should be not less than 15 m,and that on the foot wall side should be not less than 10 m.This research work has important significance for safe site selection in Longmenshan region during reconstruction after the earthquake.
The Wenchuan earthquake occurred along the Longmenshan thrust fault belt.The Longmenshan central fault is the earthquake causing fault.The total rupture length along the Longmenshan central fault caused by the Wenchuan earthquake is about 270 km and the average vertical and horizontal displacement range from 1.0 m to 5.0 m,up to about 9.8 m in local parts.A lot of buildings were broken in the area where the ruptures passed through.In this paper,the authors report the investigation results of the vertical and horizontal displacements,as well as the width of rupture influenced zones which were confirmed by the geophysical survey methods,in different locations along the Longmenshan central fault.It is indicated that the influenced scopes of the earthquake ruptures mainly range from16 m to 60 m,and the relationship between the influenced scopes(D)and the vertical displacement(H)is obvious linearity,which can be expressed as:D=10.11H+16.0.Due to the Longmenshan central fault being a mainly thrusting fault,the influenced zone ratio between the hanging wall side and the foot wall side is generally from 3:1 to 2:1,which can help to determinate the safe distance for building site.On the basis of field investigation and using overseas experience for reference,the limit of the safe distance on the hanging wall side should be not less than 15 m,and that on the foot wall side should be not less than 10 m.This research work has important significance for safe site selection in Longmenshan region during reconstruction after the earthquake.
引文
[1]Dong Shuwen,Zhang Yueqiao.Surface rupture and co-seisnic dis-placement produced by theMs8.0Wenchuan earthquake of May12th,2008,Sichuan,China:Eastwards growth of the Qinghai-Tibet Plateau[J].Acta Geologica Sinica,2008,82(5):938～948.
[2]Xiwei Xu,Xueze Wen,Guihua YU.Coseismic reverse-and oblique-slip surface faulting generated by the2008Mw7.9Wenchuan earth-quake,China.Geology[J],2009,37(6):515～518.
[3]李锡堤,郑锦桐,廖启雯.9.21集集大地震的地盘变形现象及断层禁限建问题[A].见:第八届台湾地区地球物理研讨会论文集.2000,pp669～675.Li Xidi,Zheng Jintong,Liao Qiwen.Ground deformation of the Chi-Chi Earthquake and problems of no or limited construction on active faults.In:Collection Papers of the8th Taiwan Geophysics Meeting,Taibei.2000,pp669～675.
[4]徐锡伟,于贵华,马文涛等.活断层地震地表破裂“避让带”宽度确定的依据与方法[J].地震地质,2002,24(4):470～483.Xu Xiwei,Yu Guihua,Ma Wentao,et al.Evidence and methods for determining the safety distance from the potential earthquake surface rupture on active fault.Seismology and Geology,2002,24(4):470～483.
[5]Kelson K I,Kang K H,Page W D,et al.Representative styles of deformation along the Chelungpu Fault from the1999ChiChi(Tai-wan)Earthquake:Geomorphic characteristics and responses of man made structures.Bull Seism Soc Am,2001,91(5):930～952.
[6]Lee J C,Chen Y G,Sieh K,et al.A vertical exposure of the1999surface rupture of the Chelungpu Fault at Wufeng,Western Taiwan:structural and paleoseismic implications for an active thrust fault[J].Bull Seism Soc Am,2001,91(5):914～929.
[7]中华人民共和国建设部,国家质量监督检验检疫总局.2001.建筑抗震设计规范(GB50011-2001)[S].北京:中国建筑工业出版社.Ministry of Construction of the Peoples Republic of China,General Administration of Quality Supervision,Inspection and Quarantine of the Peoples Republic of China.Code for Seismic Design of Buildings(GB50011-2001).China Architectural Industry Press,Beijing.2001.
[8]周庆,徐锡伟,于贵华等.汶川8.0级地震地表破裂带宽度调查[J].地震地质,2008,30(3):778～788.Zhou Qing,Xu Xiwei,Yu Guihua,et al.Investigation on Widths of Surface Rupture Zones of The M8.0Wenchuan Earthquake,Sichuan Province,China.Seismology and Geology,2008,30(3):778～788.
[9]张永双,雷伟志,石菊松等.四川省北川县擂鼓盆地地壳稳定性与城镇选址[J],地质学报,2008,82(12):1758～1768.Zhang Yongshuang,Lei Weizhi,Shi Jusong,et al.Crustal stability of the Leigu Basin in Beichuan County,Sichuan province and its possi-bility for a new town site.Acta Geologica Sinica,2008,82(12):1758～1768.
[10]Earl W Hand William A B.Fault-Rupture Hazard Zones in Cali-fornia:Alquist-Priolo Earthquake Fault Zoning Act with Index to Earthquake Fault Zones Maps[S].California Department of Con-servation Division of Mines and Geology.1997.
[11]刘云华,张晓帆.乌鲁木齐市活断层避让带多层建筑物三维动力反应分析[J].华南地震,2007,27(1):86～97.Liu Yunhua,Zhang Xiaofan.3-D dynamic response analysis of the buildings near fault site in Urumqi.South China Journal of Seis-mology,2007,27(1):86～97.
[2]Xiwei Xu,Xueze Wen,Guihua YU.Coseismic reverse-and oblique-slip surface faulting generated by the2008Mw7.9Wenchuan earth-quake,China.Geology[J],2009,37(6):515～518.
[3]李锡堤,郑锦桐,廖启雯.9.21集集大地震的地盘变形现象及断层禁限建问题[A].见:第八届台湾地区地球物理研讨会论文集.2000,pp669～675.Li Xidi,Zheng Jintong,Liao Qiwen.Ground deformation of the Chi-Chi Earthquake and problems of no or limited construction on active faults.In:Collection Papers of the8th Taiwan Geophysics Meeting,Taibei.2000,pp669～675.
[4]徐锡伟,于贵华,马文涛等.活断层地震地表破裂“避让带”宽度确定的依据与方法[J].地震地质,2002,24(4):470～483.Xu Xiwei,Yu Guihua,Ma Wentao,et al.Evidence and methods for determining the safety distance from the potential earthquake surface rupture on active fault.Seismology and Geology,2002,24(4):470～483.
[5]Kelson K I,Kang K H,Page W D,et al.Representative styles of deformation along the Chelungpu Fault from the1999ChiChi(Tai-wan)Earthquake:Geomorphic characteristics and responses of man made structures.Bull Seism Soc Am,2001,91(5):930～952.
[6]Lee J C,Chen Y G,Sieh K,et al.A vertical exposure of the1999surface rupture of the Chelungpu Fault at Wufeng,Western Taiwan:structural and paleoseismic implications for an active thrust fault[J].Bull Seism Soc Am,2001,91(5):914～929.
[7]中华人民共和国建设部,国家质量监督检验检疫总局.2001.建筑抗震设计规范(GB50011-2001)[S].北京:中国建筑工业出版社.Ministry of Construction of the Peoples Republic of China,General Administration of Quality Supervision,Inspection and Quarantine of the Peoples Republic of China.Code for Seismic Design of Buildings(GB50011-2001).China Architectural Industry Press,Beijing.2001.
[8]周庆,徐锡伟,于贵华等.汶川8.0级地震地表破裂带宽度调查[J].地震地质,2008,30(3):778～788.Zhou Qing,Xu Xiwei,Yu Guihua,et al.Investigation on Widths of Surface Rupture Zones of The M8.0Wenchuan Earthquake,Sichuan Province,China.Seismology and Geology,2008,30(3):778～788.
[9]张永双,雷伟志,石菊松等.四川省北川县擂鼓盆地地壳稳定性与城镇选址[J],地质学报,2008,82(12):1758～1768.Zhang Yongshuang,Lei Weizhi,Shi Jusong,et al.Crustal stability of the Leigu Basin in Beichuan County,Sichuan province and its possi-bility for a new town site.Acta Geologica Sinica,2008,82(12):1758～1768.
[10]Earl W Hand William A B.Fault-Rupture Hazard Zones in Cali-fornia:Alquist-Priolo Earthquake Fault Zoning Act with Index to Earthquake Fault Zones Maps[S].California Department of Con-servation Division of Mines and Geology.1997.
[11]刘云华,张晓帆.乌鲁木齐市活断层避让带多层建筑物三维动力反应分析[J].华南地震,2007,27(1):86～97.Liu Yunhua,Zhang Xiaofan.3-D dynamic response analysis of the buildings near fault site in Urumqi.South China Journal of Seis-mology,2007,27(1):86～97.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心