郴州市某煤系地层滑坡成因机制及滑动过程分析
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摘要
本文以郴州市龙家背滑坡为研究对象,分析该滑坡的成因过程及机理。经勘察研究发现,此滑坡属推移式与牵引式复合型的岩土混合滑坡,破坏模式为典型的拉裂-蠕滑缓动型变形破坏模式。郴州独特的煤系地层是滑坡产生的主要内因,通过UU试验分析二叠系上统龙潭组页岩煤系地层特殊岩土力学性质,总结其力学参数随含水率的升高显著下降的变化规律,并分析对比滑带土室内试验结果,发现经地下水软化后的滑带的含水率约为35%,强度较干燥状态下降约71.4%;坡脚切方施工是最终形成复合式滑坡的触发因素,运用改进毕肖普法计算挖方前后坡脚土体的稳定性,坡体稳定性系数由1.13下降至0.93,坡体失稳滑动。郴州市山岭地区独特的煤系地层,加之春秋多暴雨的特殊气候条件,在工程建设中极易触发产生滑坡等次生灾害。本文依托此龙家背滑坡,分析其破坏过程及成因机理,为今后城市建设中的灾害防治提供参考和理论支持。
In this paper, the Longjiabei landslide in Chenzhou is taken as the research object toanalyse the genetic process and mechanism of the landslide. Through investigation and research, it is found that the landslide belongs to the mixed type of rock and soil landslide, which is a typical failure mode of crack—creep. The unique coal-bearing strata in Chenzhou are the main internal reasons of the landslide. The unique coal measure strata in Chenzhou are the main internal causes of the landslide.Through the UU test, the special geotechnical properties of the strata of the upper Permian Longtan shale coal system are analyzed, and the regularity that the mechanical parameters decrease significantly with the increase of water content are summarized. By comparing the results of laboratory tests with slippery soil, it is found that the water content of the slippery soil softened by groundwater is about35%, and the strength decreased by about 71.4% compared with the dry state. The construction of slope cutting is the trigger factor for the final compound landslide. The stability of the slope soil is calculated by using the improved Bishop method. and the stability coefficient of the slope is reduced from 1.13 to 0.93. The unique coal-bearing strata in the mountain area of Chenzhou and the special climatic conditions of heavy rain in spring and autumn are very easy to trigger secondary disasters such as landslides in construction. Based on the Longjiabei landslide, this paper analyzes its failure process and genetic mechanism, and provides reference and theoretical support for disaster prevention and control in urbanconstruction in the future.
In this paper, the Longjiabei landslide in Chenzhou is taken as the research object toanalyse the genetic process and mechanism of the landslide. Through investigation and research, it is found that the landslide belongs to the mixed type of rock and soil landslide, which is a typical failure mode of crack—creep. The unique coal-bearing strata in Chenzhou are the main internal reasons of the landslide. The unique coal measure strata in Chenzhou are the main internal causes of the landslide.Through the UU test, the special geotechnical properties of the strata of the upper Permian Longtan shale coal system are analyzed, and the regularity that the mechanical parameters decrease significantly with the increase of water content are summarized. By comparing the results of laboratory tests with slippery soil, it is found that the water content of the slippery soil softened by groundwater is about35%, and the strength decreased by about 71.4% compared with the dry state. The construction of slope cutting is the trigger factor for the final compound landslide. The stability of the slope soil is calculated by using the improved Bishop method. and the stability coefficient of the slope is reduced from 1.13 to 0.93. The unique coal-bearing strata in the mountain area of Chenzhou and the special climatic conditions of heavy rain in spring and autumn are very easy to trigger secondary disasters such as landslides in construction. Based on the Longjiabei landslide, this paper analyzes its failure process and genetic mechanism, and provides reference and theoretical support for disaster prevention and control in urbanconstruction in the future.
引文
[1]陈宾.彬州地区残坡积土工程边坡过程稳定性研究及控制[D].中南大学, 2010.
[2]张毅,韩尚宇,郑军辉.降雨入渗对含裂隙煤系土边坡稳定性影响分析[J].公路工程, 2014(1):10-13.
[3]祝磊,洪宝宁.煤系土浅层滑坡的影响因素敏感性分析[J].长江科学院院报, 2011, 28(7):67-71.
[4]祝磊,洪宝宁.降雨作用下煤系土路堑边坡稳定分析[J].岩土力学, 2009, 30(4):1035-1040.
[5]李勇,雷学文,孟庆山,等.非饱和玄武岩残积土强度特性及其边坡稳定性分析[J].公路交通科技, 2017,34(5):50-56.
[6]谢云峰.湖南省郴州市梨树山滑坡的成因机制及防治[J].中国地质灾害与防治学报, 2006, 17(3):165-166.
[7]田卿燕,肖春发,吕建兵.粤北山区高速公路煤系地层滑坡机理分析[J].铁道科学与工程学报, 2008,5(5):61-64.
[2]张毅,韩尚宇,郑军辉.降雨入渗对含裂隙煤系土边坡稳定性影响分析[J].公路工程, 2014(1):10-13.
[3]祝磊,洪宝宁.煤系土浅层滑坡的影响因素敏感性分析[J].长江科学院院报, 2011, 28(7):67-71.
[4]祝磊,洪宝宁.降雨作用下煤系土路堑边坡稳定分析[J].岩土力学, 2009, 30(4):1035-1040.
[5]李勇,雷学文,孟庆山,等.非饱和玄武岩残积土强度特性及其边坡稳定性分析[J].公路交通科技, 2017,34(5):50-56.
[6]谢云峰.湖南省郴州市梨树山滑坡的成因机制及防治[J].中国地质灾害与防治学报, 2006, 17(3):165-166.
[7]田卿燕,肖春发,吕建兵.粤北山区高速公路煤系地层滑坡机理分析[J].铁道科学与工程学报, 2008,5(5):61-64.