大西安地区滑坡分类及其特征分析
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摘要
大西安正在进行国际化大都市的建设,建设过程中的政府决策、防灾减灾、规划设计、施工与运营管理等环节都面临着许多与岩土体和地质环境相关的重大问题,尤其是滑坡治理与预报工作。本文通过大量野外调查、测绘和勘查,统计分析了大西安地区发育的滑坡,将大西安地区的滑坡按滑体特征、动力成因和滑动特征分为三大类,又进一步按诱发因素、物质组成、滑面埋深、滑体规模和力学性质进行相应的分类,并从滑坡形貌、滑带与纵断面、变形与运动特征等方面对大西安地区发育的滑坡进行了归纳总结,建立了大西安地区具有层次性的滑坡分类体系。为大西安地区滑坡监测预报和稳定性分析等奠定了基础,为该区的防灾减灾工作提供理论依据。
Background, aim, and scope The study site is located in the inland region of mid-latitudes characterizing a temperate and monsoon climate. Due to the change of meteorological factors, there is often disastrous weather, such as rainstorms, continuous rain and so on, which not only causes floods, but leads to natural landslides. Meanwhile, the new tectonic movement is active in the region and the terrain is complex and changeable. As a result, the landslides in the region develop fully with large density and strong intensity. Materials and methods Through a lot of field investigations and statistical analysis, the authors established the landslide classification system. Results The landslides in greater Xi'an region are mainly loess landslides, induced by rainfall and human engineering activities, which is mainly due to the special loess sediments with high heterogeneity, porosity, erect and collapsibility, the vertical joints fully formed in the loessificaion process and nearly vertical structural joints formed under tectonic stress in the late stage. Besides, with erosional surface falling and the slope height increasing under the rain and gravity, the slope stress increases constantly and is relatively more concentrated. Thus, the micro cracks form the shear zone and these failure surfaces facilitate the erosion of rain, surface water and groundwater. On the one hand, the action of water facilitates the development of the sliding surface. On the other hand, the softening and argillitization of the sliding surface soil greatly reduce the friction between the upper and lower part of the failure surface, leading to the occurrence of landslides. Discussion The initial formation, development, generation and even extinction of the landslides are always affected by both the internal and external factors. Among them, the sliding body composition, geological conditions and mechanical properties are intrinsic factors and the dynamic origins(predisposing factors) are external ones, including material composition, mechanical properties and dynamic reasons, which is an important basis for landslide classification. In the process of constructing an international metropolis of Xi'an, the government decisions, disaster prevention and mitigation, planning and design, construction and operation management are faced with many major issues related to rock-soil mass and geological environment, especially landslides' treatment and forecast. Based on field investigations, the present study analyzed the landslides in greater Xi'an and established a hierarchical landslide classification system which classified the landslides in greater Xi'an into three types, namely landslide characteristics, formation causes and sliding features. It further classified the landslides based on the inducing factors, material composition, embedded depth of sliding surface, sliding scale and mechanical properties. Additionally, the characteristics of landslides in greater Xi'an were summarized from the aspects of landslide morphology, sliding zone and longitudinal section as well as deformation and movement characteristics. The above analysis lays a foundation for establishing a geological model system of landslides monitoring, predicting and analyzing stability, which provides a theoretical basis for preventing and mitigating disasters in the region. Conclusions The occurrence of landslide is related to the type and characteristics of landslides and the landslides in greater Xi'an region are also related to loess, rainfall and human activities. Therefore, it is necessary to study the characteristics and types of landslide hazards in the area, which can provide theoretical basis for disaster prevention and mitigation in order to achieve the goal of the harmonious development between urban development and environment. Recommendations and perspectives We must also try our best to monitor and prevent landslides, especially in rainy seasons. Besides, we need to further landslide study in the area to provide a theoretical basis for the establishment of landslide monitoring, prediction, stability analysis, the disaster prevention and mitigation work.
Background, aim, and scope The study site is located in the inland region of mid-latitudes characterizing a temperate and monsoon climate. Due to the change of meteorological factors, there is often disastrous weather, such as rainstorms, continuous rain and so on, which not only causes floods, but leads to natural landslides. Meanwhile, the new tectonic movement is active in the region and the terrain is complex and changeable. As a result, the landslides in the region develop fully with large density and strong intensity. Materials and methods Through a lot of field investigations and statistical analysis, the authors established the landslide classification system. Results The landslides in greater Xi'an region are mainly loess landslides, induced by rainfall and human engineering activities, which is mainly due to the special loess sediments with high heterogeneity, porosity, erect and collapsibility, the vertical joints fully formed in the loessificaion process and nearly vertical structural joints formed under tectonic stress in the late stage. Besides, with erosional surface falling and the slope height increasing under the rain and gravity, the slope stress increases constantly and is relatively more concentrated. Thus, the micro cracks form the shear zone and these failure surfaces facilitate the erosion of rain, surface water and groundwater. On the one hand, the action of water facilitates the development of the sliding surface. On the other hand, the softening and argillitization of the sliding surface soil greatly reduce the friction between the upper and lower part of the failure surface, leading to the occurrence of landslides. Discussion The initial formation, development, generation and even extinction of the landslides are always affected by both the internal and external factors. Among them, the sliding body composition, geological conditions and mechanical properties are intrinsic factors and the dynamic origins(predisposing factors) are external ones, including material composition, mechanical properties and dynamic reasons, which is an important basis for landslide classification. In the process of constructing an international metropolis of Xi'an, the government decisions, disaster prevention and mitigation, planning and design, construction and operation management are faced with many major issues related to rock-soil mass and geological environment, especially landslides' treatment and forecast. Based on field investigations, the present study analyzed the landslides in greater Xi'an and established a hierarchical landslide classification system which classified the landslides in greater Xi'an into three types, namely landslide characteristics, formation causes and sliding features. It further classified the landslides based on the inducing factors, material composition, embedded depth of sliding surface, sliding scale and mechanical properties. Additionally, the characteristics of landslides in greater Xi'an were summarized from the aspects of landslide morphology, sliding zone and longitudinal section as well as deformation and movement characteristics. The above analysis lays a foundation for establishing a geological model system of landslides monitoring, predicting and analyzing stability, which provides a theoretical basis for preventing and mitigating disasters in the region. Conclusions The occurrence of landslide is related to the type and characteristics of landslides and the landslides in greater Xi'an region are also related to loess, rainfall and human activities. Therefore, it is necessary to study the characteristics and types of landslide hazards in the area, which can provide theoretical basis for disaster prevention and mitigation in order to achieve the goal of the harmonious development between urban development and environment. Recommendations and perspectives We must also try our best to monitor and prevent landslides, especially in rainy seasons. Besides, we need to further landslide study in the area to provide a theoretical basis for the establishment of landslide monitoring, prediction, stability analysis, the disaster prevention and mitigation work.
引文
段钊,彭建兵,冷艳秋.2016.泾阳南塬Q2黄土物理力学特性[J].长安大学学报自然科学版,36(5):60-66.[Duan Z,Peng J B,Leng Y Q.2016.Physico-mechanical characteristics of Q2 loess in Southern Plateau of Jingyang[J].Journal of Chang’an University(Natural Science Edition),36(5):60-66.]
盖海龙,谢婉丽,许元珺.2015.基于模糊评判法的长安区滑坡崩塌灾害易发性分区评价[J].安徽农业科学,43(17):155-156.[Gai H L,Xie W L,Xu Y J.2015.Evaluation of the partition of Chang’an District landslide disaster prone based on the fuzzy judgment method[J].Journal of Anhui Agricultural Sciences,43(17):155-156.]
葛瑞华,谢婉丽,冯立.2015.泾阳南塬Q3黄土吸湿特性试验研究[J].西北地质,48(4):218-225.[Ge R H,Xie W L,Feng L.2015.Experimental research on hygroscopic properties of Q3 loess in the southern tableland of Jingyang County[J].Northwestern Geology,48(4):218-225.]
何小亮,谢婉丽,丁勇.2010.泾阳南塬黄土剪切强度的三轴试验研究[J].工程地质学报,18(S1):76-80.[He X L,Xie W L,Ding Y.2010.Study on triaxial test of shear strength of loess in southern Jingyang County[J].Journal of Engineering Geology,18(S1):76-80.]
黄玉华.2002.泾阳南塬黄土滑坡特征及其灾害损失经济评价[D].西安:西北大学.[HuangY H.2002.The characteristics and hazard losses economic assessment of loess landslide in southern Yuan of Jingyang[D].Xi’an:Northwest University.]
雷祥义.1995.陕西泾阳南塬黄土滑坡灾害与引水灌溉的关系[J].工程地质学报,3(1):56-64.[Lei X Y.1995.The hazards of loess landslides in the southern tableland of Jingyang County,Shaanxi and their relationship with the channel water into fi elds[J].Journal of Engineering Geology,3(1):56-64.]
刘广润,晏鄂川,练操.2002.论滑坡分类[J].工程地质学报,10(4):339-342.[Liu G R,Yan E C,Lian C.2002.Discussion on classification of landslides[J].Journal of Engineering Geology,10(4):339-342.]
宋克强,袁继国,崔中兴,等.1994.西安地区滑坡特征及其预报研究[J].水土保持学报,8(1):51-58.[Song K Q,Yuan J G,Cui Z X,et al.1994.The study on the characteristic and prediction of landslides in Xi’an area[J].Journal of Soil and Water Conservation,8(1):51-58.]
滕宏泉,谢婉丽,盖海龙,等.2016.分形分维理论在地质灾害发育及空间分布规律中的应用--以长安区滑坡、崩塌地质灾害为例[J].地质灾害与环境保护,27(1):44-50.[Teng H Q,Xie W L,Gai H L,et al.2016.Application of fractal dimension theory in geological hazard development and spatial distribution law-taking Chang’an District landslide and collapse as an example[J].Journal of Geological Hazards and Environment Preservation,27(1):44-50.]
王念秦,张倬元.2005.黄土滑坡灾害研究[M].兰州:兰州大学出版社:1-6.[Wang N Q,Zhang Z Y.2005.Study on loess landslide disaster[M].Lanzhou:Lanzhou University Press:1-6.]
谢婉丽,葛瑞华,郭倩怡,等.2017.灌溉作用下黄土宏观力学响应及微观结构特性研究[J].水文地质工程地质,44(2):82-89.[Xie W L,Ge R H,Guo Q Y,et al.2017.A study of macro mechanical response and microstructure characteristics of loess under irrigation mechanism[J].Hydrogeology and Engineering Geology,44(2):82-89.]
谢婉丽,王延寿,马中豪,等.2015.黄土湿陷机理研究现状及发展趋势[J].现代地质,29(2):397-407.[Xie WL,Wang Y S,Ma Z H,et al.2015.Research status and prospect of loess collapsibility mechanism[J].Geoscience,29(2):397-407.]
许领,戴福初.2008.泾阳南塬黄土滑坡特征参数统计分析[J].水文地质工程地质,35(5):28-32.[Xu L,Dai F C.2008.Statistical analysis of the characteristic parameters of loess landslides at the South Jingyang Plateau[J].Hydrogeology and Engineering Geology,35(5):28-32.]
张茂省,胡炜,孙萍萍,等.2016.黄土水敏性及水致黄土滑坡研究现状与展望[J].地球环境学报,7(4):323-334.[Zhang M S,Hu W,Sun P P.2016.Advances and prospects of water sensitivity of loess and the induced loess landslides[J].Journal of Earth Environment,7(4):323-334.]
赵秋鹏.2014.灌溉作用下陕西省泾阳县张村湾黄土滑坡形成机理及稳定性分析研究[D].西安:西北大学.[Zhao Q P.2014.The formation mechanism and stability analysis under the irrigation of Zhangcunwan loess landslide in Jingyang county,Shaanxi province[D].Xi’an:Northwest University.]
盖海龙,谢婉丽,许元珺.2015.基于模糊评判法的长安区滑坡崩塌灾害易发性分区评价[J].安徽农业科学,43(17):155-156.[Gai H L,Xie W L,Xu Y J.2015.Evaluation of the partition of Chang’an District landslide disaster prone based on the fuzzy judgment method[J].Journal of Anhui Agricultural Sciences,43(17):155-156.]
葛瑞华,谢婉丽,冯立.2015.泾阳南塬Q3黄土吸湿特性试验研究[J].西北地质,48(4):218-225.[Ge R H,Xie W L,Feng L.2015.Experimental research on hygroscopic properties of Q3 loess in the southern tableland of Jingyang County[J].Northwestern Geology,48(4):218-225.]
何小亮,谢婉丽,丁勇.2010.泾阳南塬黄土剪切强度的三轴试验研究[J].工程地质学报,18(S1):76-80.[He X L,Xie W L,Ding Y.2010.Study on triaxial test of shear strength of loess in southern Jingyang County[J].Journal of Engineering Geology,18(S1):76-80.]
黄玉华.2002.泾阳南塬黄土滑坡特征及其灾害损失经济评价[D].西安:西北大学.[HuangY H.2002.The characteristics and hazard losses economic assessment of loess landslide in southern Yuan of Jingyang[D].Xi’an:Northwest University.]
雷祥义.1995.陕西泾阳南塬黄土滑坡灾害与引水灌溉的关系[J].工程地质学报,3(1):56-64.[Lei X Y.1995.The hazards of loess landslides in the southern tableland of Jingyang County,Shaanxi and their relationship with the channel water into fi elds[J].Journal of Engineering Geology,3(1):56-64.]
刘广润,晏鄂川,练操.2002.论滑坡分类[J].工程地质学报,10(4):339-342.[Liu G R,Yan E C,Lian C.2002.Discussion on classification of landslides[J].Journal of Engineering Geology,10(4):339-342.]
宋克强,袁继国,崔中兴,等.1994.西安地区滑坡特征及其预报研究[J].水土保持学报,8(1):51-58.[Song K Q,Yuan J G,Cui Z X,et al.1994.The study on the characteristic and prediction of landslides in Xi’an area[J].Journal of Soil and Water Conservation,8(1):51-58.]
滕宏泉,谢婉丽,盖海龙,等.2016.分形分维理论在地质灾害发育及空间分布规律中的应用--以长安区滑坡、崩塌地质灾害为例[J].地质灾害与环境保护,27(1):44-50.[Teng H Q,Xie W L,Gai H L,et al.2016.Application of fractal dimension theory in geological hazard development and spatial distribution law-taking Chang’an District landslide and collapse as an example[J].Journal of Geological Hazards and Environment Preservation,27(1):44-50.]
王念秦,张倬元.2005.黄土滑坡灾害研究[M].兰州:兰州大学出版社:1-6.[Wang N Q,Zhang Z Y.2005.Study on loess landslide disaster[M].Lanzhou:Lanzhou University Press:1-6.]
谢婉丽,葛瑞华,郭倩怡,等.2017.灌溉作用下黄土宏观力学响应及微观结构特性研究[J].水文地质工程地质,44(2):82-89.[Xie W L,Ge R H,Guo Q Y,et al.2017.A study of macro mechanical response and microstructure characteristics of loess under irrigation mechanism[J].Hydrogeology and Engineering Geology,44(2):82-89.]
谢婉丽,王延寿,马中豪,等.2015.黄土湿陷机理研究现状及发展趋势[J].现代地质,29(2):397-407.[Xie WL,Wang Y S,Ma Z H,et al.2015.Research status and prospect of loess collapsibility mechanism[J].Geoscience,29(2):397-407.]
许领,戴福初.2008.泾阳南塬黄土滑坡特征参数统计分析[J].水文地质工程地质,35(5):28-32.[Xu L,Dai F C.2008.Statistical analysis of the characteristic parameters of loess landslides at the South Jingyang Plateau[J].Hydrogeology and Engineering Geology,35(5):28-32.]
张茂省,胡炜,孙萍萍,等.2016.黄土水敏性及水致黄土滑坡研究现状与展望[J].地球环境学报,7(4):323-334.[Zhang M S,Hu W,Sun P P.2016.Advances and prospects of water sensitivity of loess and the induced loess landslides[J].Journal of Earth Environment,7(4):323-334.]
赵秋鹏.2014.灌溉作用下陕西省泾阳县张村湾黄土滑坡形成机理及稳定性分析研究[D].西安:西北大学.[Zhao Q P.2014.The formation mechanism and stability analysis under the irrigation of Zhangcunwan loess landslide in Jingyang county,Shaanxi province[D].Xi’an:Northwest University.]