跨地裂缝墙体开裂形态分析
|
摘要
应用非线性有限元法对跨地裂缝的墙体开裂形态进行了分析,确定出了具有三维活动性的地裂缝垂直穿越墙基时,墙体出现裂缝的位置、倾向、倾角和后期的发展状况,以及随沉降量与张开量比值变化的规律。结果表明:地裂缝垂直穿越围墙时,墙体上出现的裂缝一般有两种形式:一是位于地裂缝下盘的墙顶竖直裂缝,二是出现在地裂缝正上方墙体底部的斜裂缝;当地裂缝两盘的土体活动以水平拉张为主时,墙体底部出现的斜裂缝以高角度向上扩展,当地裂缝两盘的土体活动以差异沉降为主时,墙体底部出现的斜裂缝则以较缓的角度向上扩展,倾向与地裂缝相反;只要地裂缝的上下盘土体有微小的错动,一般2~3mm时,就会引起墙体的破裂,且墙体裂缝扩展迅速,几个毫米的错动量,就能使墙体裂缝扩展数十厘米,甚至贯通整个墙体;墙体斜裂缝在产生初期较为平直,随着裂缝的迅速扩展,端部稍向下弯曲,倾角减缓,整体呈弧弯状。
The author in this paper analyzed the cracking forms of walls over ground fissures with non-linear finite element method.The originated position,dip direction,dip angle and later mode of the cracks on walls are accomplished when the walls crossing over ground fissures with three-dimensional activity,and the changing law varying with different ratio of sedimentation and tensor are got.The results show that,there are two types of cracks generating on walls: the vertical cracks on top of walls located in footwall and the skew cracks at the bottom of walls just above ground fissures.The dip direction of the skew cracks is opposite to that of ground fissures.When the activity of ground fissures is mainly the tensor,the skew cracks at the bottom of walling expand upward with high angel;but when the activity is mainly the sedimentation,then the skew cracks expand upward with low angel.The walls could be broken so long as there was minute dislocation,generally 2~3 mm distance,occurred to the ground fissures.And the cracks expand quickly that several millimeters dislocation can make the cracks expand tens of centimeters,even finally breakthrough the walls.At the early developmental stage,the skew cracks are relatively flat,but with the quick expansion of cracks,the dip angles become lower.The later mode of the cracks likes a flexural arc.
The author in this paper analyzed the cracking forms of walls over ground fissures with non-linear finite element method.The originated position,dip direction,dip angle and later mode of the cracks on walls are accomplished when the walls crossing over ground fissures with three-dimensional activity,and the changing law varying with different ratio of sedimentation and tensor are got.The results show that,there are two types of cracks generating on walls: the vertical cracks on top of walls located in footwall and the skew cracks at the bottom of walls just above ground fissures.The dip direction of the skew cracks is opposite to that of ground fissures.When the activity of ground fissures is mainly the tensor,the skew cracks at the bottom of walling expand upward with high angel;but when the activity is mainly the sedimentation,then the skew cracks expand upward with low angel.The walls could be broken so long as there was minute dislocation,generally 2~3 mm distance,occurred to the ground fissures.And the cracks expand quickly that several millimeters dislocation can make the cracks expand tens of centimeters,even finally breakthrough the walls.At the early developmental stage,the skew cracks are relatively flat,but with the quick expansion of cracks,the dip angles become lower.The later mode of the cracks likes a flexural arc.
引文
[1]陈志新.地裂缝成灾机理及防御对策[J].西安工程学院学报,2002,24(2):17~20.Chen Zhixin.Mechanism of ground fissures and its preventioncountermeasures.Journal of Xi’an Engineering University,2002,24(2):17~20.
[2]王景明,王春梅,刘科.地裂缝及其灾害研究的新进展[J].地球科学进展,2001,16(3):303~313.Wang Jingming,Wang Chunmei,Liu Ke.Progress in ground fis-sures and its hazard research[J].Advance in Earth Scinences,2001,16(3):303~313.
[3]西安地裂缝场地勘查与工程设计规程(DBJ24-6-88)[S],1988.Code for Xi’an ground fissures site survey and engineering design(DBJ24-6-88),1988.
[4]王景明,等著.地裂缝及其灾害的理论与应用[M].西安:陕西科学技术出版社,2000.Wang Jingming,et al,eds..Theory of ground fissures hazardsand its application.Xi’an:Science and Technology Press ofShaanxi,2000.
[5]徐锡伟,钱瑞华,等.大同铁路分局地裂缝带的三维构造特征及其成因分析[J].地震地质,1994,16(4):356~364.Xu Xiwei,Qian Ruihua,et al.Three-dimensional structure ofthe ground fissure zone in the area of Datong railway bureau and itsorigin.Seismology and Geology,1994,16(4):356~364.
[6]李树德,袁仁茂.大同地裂缝灾害形成机理[J].北京大学学报(自然科学版),2002,38(1):104~108.Li Shude,Yuan Renmao.The formation mechanism of ground fis-sure in Datong city.Journal of Beijing University(Natural ScienceEdition),2002,38(1):104~108.
[7]彭建兵,等著.渭河盆地活动断裂与地质灾害[M].西安:西北大学出版社.1992.Peng Jian-bing,et al,eds.Active faults and geological hazardsin Weihei basin.Xi’an:Northwest University Press,1992.
[8]阚前华,常志宇.MSc.marc工程应用实例分析与二次开发[M].北京:中国水利水电出版社,2006.Han Qianhua,Chang Zhiyu.Project application example analysisof MSc.marc and its redevelopment.Beijing:Chinese Waterpub,2006.
[9]长安大学.汾渭盆地典型地区地裂缝地面沉降监测与防治研究设计[R],2006.Chang’an University.Research on typical area ground fissures andsubsidence monitor and prevention in Fenwei basin,2006.
[10]李永善,等著.西安地裂及渭河盆地活断层研究[M].北京:地震出版社,1992.Li Yongshan,et al,eds.Research on ground fissures in Xi’anregion and active faults in Weihe basin.Beijing:EarthquakePress,1992.
[11]彭建兵.中国活动构造与环境灾害研究中的若干重大问题[J].工程地质学报,2006,14(1):5~12.Peng Jianbing.Some important problems to be addressed in re-seach of active tectonics and environmental disasters in China.Journal of Engineering Geology,2006,14(1):5~12.
[12]李世雄,李守定,郜洪强.河北平原地裂缝分布特征及成因机制研究[J].工程地质学报,2006,14(2):178~183.Li Shixiong,Li Shouding,Hao Hongqiang.The distribution char-acters and origin mechanics of ground fissures hazard in Hebeiplain.Journal of Engineering Geology,2006,14(2):178~183.
[2]王景明,王春梅,刘科.地裂缝及其灾害研究的新进展[J].地球科学进展,2001,16(3):303~313.Wang Jingming,Wang Chunmei,Liu Ke.Progress in ground fis-sures and its hazard research[J].Advance in Earth Scinences,2001,16(3):303~313.
[3]西安地裂缝场地勘查与工程设计规程(DBJ24-6-88)[S],1988.Code for Xi’an ground fissures site survey and engineering design(DBJ24-6-88),1988.
[4]王景明,等著.地裂缝及其灾害的理论与应用[M].西安:陕西科学技术出版社,2000.Wang Jingming,et al,eds..Theory of ground fissures hazardsand its application.Xi’an:Science and Technology Press ofShaanxi,2000.
[5]徐锡伟,钱瑞华,等.大同铁路分局地裂缝带的三维构造特征及其成因分析[J].地震地质,1994,16(4):356~364.Xu Xiwei,Qian Ruihua,et al.Three-dimensional structure ofthe ground fissure zone in the area of Datong railway bureau and itsorigin.Seismology and Geology,1994,16(4):356~364.
[6]李树德,袁仁茂.大同地裂缝灾害形成机理[J].北京大学学报(自然科学版),2002,38(1):104~108.Li Shude,Yuan Renmao.The formation mechanism of ground fis-sure in Datong city.Journal of Beijing University(Natural ScienceEdition),2002,38(1):104~108.
[7]彭建兵,等著.渭河盆地活动断裂与地质灾害[M].西安:西北大学出版社.1992.Peng Jian-bing,et al,eds.Active faults and geological hazardsin Weihei basin.Xi’an:Northwest University Press,1992.
[8]阚前华,常志宇.MSc.marc工程应用实例分析与二次开发[M].北京:中国水利水电出版社,2006.Han Qianhua,Chang Zhiyu.Project application example analysisof MSc.marc and its redevelopment.Beijing:Chinese Waterpub,2006.
[9]长安大学.汾渭盆地典型地区地裂缝地面沉降监测与防治研究设计[R],2006.Chang’an University.Research on typical area ground fissures andsubsidence monitor and prevention in Fenwei basin,2006.
[10]李永善,等著.西安地裂及渭河盆地活断层研究[M].北京:地震出版社,1992.Li Yongshan,et al,eds.Research on ground fissures in Xi’anregion and active faults in Weihe basin.Beijing:EarthquakePress,1992.
[11]彭建兵.中国活动构造与环境灾害研究中的若干重大问题[J].工程地质学报,2006,14(1):5~12.Peng Jianbing.Some important problems to be addressed in re-seach of active tectonics and environmental disasters in China.Journal of Engineering Geology,2006,14(1):5~12.
[12]李世雄,李守定,郜洪强.河北平原地裂缝分布特征及成因机制研究[J].工程地质学报,2006,14(2):178~183.Li Shixiong,Li Shouding,Hao Hongqiang.The distribution char-acters and origin mechanics of ground fissures hazard in Hebeiplain.Journal of Engineering Geology,2006,14(2):178~183.
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