南京下蜀土滑坡灾变成因现场调查及加固处理措施
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摘要
2017年5月25日,南京市红枫路衡阳排灌站西侧一典型下蜀土在降雨以及地下水渗流作用下,局部发生了滑坡,在地质灾害勘察治理中以该滑坡(HP1和HP2)为研究对象,通过无人机航拍、裂缝量测、边坡位移监测等现场调查手段,分析了滑坡的基本特征、边界条件、影响滑坡稳定性的因素及滑坡的滑移模式,发现强降雨导致土体饱和,重度增加,抗剪强度降低是产生滑坡的直接原因。结合边坡初次滑动后的坡体持续性位移监测数据,采用Bishop法作为主要的计算方法,瑞典条分法和M-P法作为参考,复核了滑坡在自重工况和暴雨工况下的稳定系数,并依据Bishop法得到滑坡的设计推力,采用抗滑桩为主要支护手段对滑坡进行综合治理,使滑坡的安全系数满足设计值,可使滑坡处于稳定状态。
Taking the typical Xiashu soil landslide in Nanjing as research object, field investigation means such as UAV aerial photograph, crack measurement and slope displacement monitoring, the basic characteristics,boundary conditions, influence factors, and slide modes for the landslide are analyzed. It is found that heavy rainfall leads to soil saturation, severe increase, and the decrease of shear strength is the direct cause of the landslide. With the continuous displacement monitoring of slope body after the initial sliding,the calculation methods, such as Bishop method, Sweden method and M-P method, are used to evaluate the slope stability. The stability factor of the slope under natural and rainstorm condition are obtained. The design trusts of landslide are obtained based on Bishop method. The anti-slide pile is considered as reinforcement measure to reinforce the landslide. The stability factor of the reinforced landside meets to design value of code and the slope is in stability state.
Taking the typical Xiashu soil landslide in Nanjing as research object, field investigation means such as UAV aerial photograph, crack measurement and slope displacement monitoring, the basic characteristics,boundary conditions, influence factors, and slide modes for the landslide are analyzed. It is found that heavy rainfall leads to soil saturation, severe increase, and the decrease of shear strength is the direct cause of the landslide. With the continuous displacement monitoring of slope body after the initial sliding,the calculation methods, such as Bishop method, Sweden method and M-P method, are used to evaluate the slope stability. The stability factor of the slope under natural and rainstorm condition are obtained. The design trusts of landslide are obtained based on Bishop method. The anti-slide pile is considered as reinforcement measure to reinforce the landslide. The stability factor of the reinforced landside meets to design value of code and the slope is in stability state.
引文
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[2]Rahardjo H,Li X W,Toll D G,et al.The effect of antecedent rainfall on slope stability[J].Geotechnical and Geological Engineering,2001,19(3):371-399.
[3]谈金忠,倪秀平,王卫东,等.南京燕子矶滑坡地质灾害治理工程及其综合利用[J].地质灾害与环境保护,2009,(4):11-15.
[4]田东方,刘德富.土质边坡非饱和渗流场与应力场耦合数值分析[J].岩土力学,2009,(3):810-814.
[5]肖进.杨柳垭滑坡应急处置工程实践[J].地质灾害与环境保护,2011,(2):65-70.
[6]党进谦,李靖.非饱和黄土的结构强度和抗剪强度[J].水利学报,2001(7):79-84.
[7]郑祥民.长江三角洲及海域风尘沉积与环境[M].上海:华东师范大学出版社,1999.
[8]韩爱民,肖军华,乔春元,等.三轴压缩下南京下蜀土的宏、微观性状试验[J].吉林大学学报(地球科学版),2013,(6):1897-1903.
[9]李晶.宁镇地区下蜀土滑坡区域预测预报研究[D].河海大学,2006.
[10]曾凡稳.南京地区下蜀土滑坡稳定性影响因素分析[J].路基工程,2010,(2):132-134.
[11]江苏省地质调查研究院.南京市栖霞区燕子矶中学斜坡地质灾害勘查报告[R].江苏省地质调查研究院,2004.3
[12]江苏省地质调查研究院.南京市栖霞区燕子矶街道太平村75-4号滑坡地质灾害勘查报告[R].江苏省地质调查研究院,2015.
[13]江苏省地质调查研究院.南京市鼓楼区旅游学校西侧山体等6个地质灾害点治理工程勘查报告(一期工程)[R].江苏省地质调查研究院,2017.4
[14]江苏省地质调查研究院.南京市鼓楼区旅游学校西侧山体等6个地质灾害点治理工程勘查报告(二期工程)[R].江苏省地质调查研究院,2017.4
[15]李徐生,韩志勇,杨守业,等.镇江下蜀土剖面的化学风化强度与元素迁移特征[J].地理学报,2007,62(11):1174-1184.