采动作用下岩溶山体深大裂隙扩展贯通机理研究     

杨忠平  蒋源文  李滨  高杨  刘新荣  赵亚龙 《地质力学学报》2020,26(4):459-470

岩溶坡体裂隙的扩展贯通是造成坡体失稳破坏的重要因素。为研究采动作用下高陡岩溶坡体随裂隙扩展贯通的失稳破坏机理，采用离散元（Universal Distinct Element Code，UDEC）数值模拟，研究了采动作用下坡体裂隙的发展规律。研究结果表明:采动作用对岩溶坡体的稳定性具有重要的影响作用，主要表现在煤层上覆岩体新生裂隙的发育以及诱发坡体原有裂隙的扩展；坡体内部裂隙的发育具有一定的时空效应，裂隙带高度随着采空区范围的增加而增加；坡体原有深大裂隙对坡体的破坏具有控制作用，坡体破坏时崩滑体沿着主控裂隙发生滑动；二维模型显示，含深大裂隙岩溶坡体在采动作用下形成类似"悬臂梁结构"，悬臂梁结构沿着主控裂隙发生断裂，坡体中间软岩被挤出，最终主控裂隙与临空面扩展贯通，坡体发生崩塌破坏。   相似文献   

湖南怀新高速公路某路堑滑坡成因及稳定性分析     

左桂四 《地质灾害与环境保护》2020,(1):44-50

沪昆高速怀化至新晃段K73+590^+730段左侧路堑高边坡,在修建过程中发生了滑坡。通过野外地质调绘及勘察,揭露了该滑坡的滑体、滑带、滑床岩土性状;结合滑坡变形特征和监测资料,分析了滑坡的成因机制;利用试验和反演确定了滑带抗剪参数,计算了不同工况下的滑坡稳定性和剩余下滑力。通过地质分析,结合计算结果,该滑坡将继续变形并向两侧及后缘扩展,甚至显著滑动,必须采取有效的防治措施。该滑坡实例的分析研究成果,对类似工程具有借鉴意义。  相似文献   

剪应变增量在堆积体边坡稳定性研究中的应用   总被引：9，自引：0，他引：9  

丁秀美  刘光士  黄润秋  严明  林锋  郑达 《地球科学进展》2004,(Z1)

堆积体边坡是我国西南地区普遍可见的一类边坡,而此类边坡的失稳(特别是滑动失稳),一般沿剪应变最大的部位发生。利用快速拉各朗日程序(FLAC-3D),对澜沦江中游某堆积体边坡划分足够细化的单元,通过最大剪应变增量找出坡体内薄弱部位,即最容易失稳的部位,结合变形特征对其稳定性进行了评价;同时与“最危险滑弧”搜索的最危险滑动范围对比表明,二者具有较好的一致性。  相似文献   

A fluidized landslide on a natural slope by artificial rainfall   总被引：9，自引：5，他引：4  

Hirotaka?Ochiai  Yasuhiko?OkadaEmail author  Gen?Furuya  Yoichi?Okura  Takuro?Matsui  Toshiaki?Sammori  Tomomi?Terajima  Kyoji?Sassa 《Landslides》2004,1(3):211-219

An experiment to induce a fluidized landslide by artificial rainfall was conducted on a natural slope at Mt. Kaba-san in the village of Yamato, Ibaraki Prefecture, Japan. The experimental slope was 30 m long, 5 m wide, and the average slope gradient was 33°. A landslide initiated 24,627.5 s (410 m/27.5 s) after the start of sprinkling at a rainfall intensity of 78 mm/h. The landslide mass was 14 m long and 1.2 m deep (at maximum). It first slid, then fluidized, and changed into a debris flow. The travel distance was up to 50 m in 17s. The apparent friction angle of the fluidized landslide was 16.7°. Formation of the sliding surface was detected by soil-strain probes. Motion of the surface of the failed landslide mass was determined by stereo photogrammetry.  相似文献   

Constituents and features of displacement vector angle of colluvial landslide     

He?KeqiangEmail author  Wang?Sijing 《Environmental Geology》2003,45(2):279-285

Based on an analysis of displacement-monitoring data of Xintan landslide, China, it was discovered that the whole stability of large-scale colluvial landslides can be more accurately described by taking the displacement vector angle into account, and the stability trend of a slope can be evaluated and predicted using the displacement vector angle. This paper also further indicates that the monitored deformation vector angle can be divided into sliding deformation vector angle, plastic-deformation vector angle, compressive deformation vector angle and creep deformation vector angle in terms of the displacement properties of the slope. Through the analysis it is found that the displacement vector angle, for which there is no substitute, is an important parameter serving as an explicit criterion for the stability of the slope, and hence its significance in the prediction of landslides. It is also shown that as far as the displacement vector angle is concerned, there are different constituents and features in the different deformation stage of colluvial landslide. On the basis of these and using the principles of statistics, a discussion on the stability of the colluvial slopes is carried out in terms of the monitoring data of F-series points on Xintan slope. The analysis results coincided with the destabilized time and the sliding laws, thus demonstrating that the parameter of the displacement vector angle has to a certain extent, very important significance in the forecasting of landslides.  相似文献   

Construction and post-construction behaviour of a geogrid-reinforced steep slope     

Agostinho Mendonça  M-Lurdes Lopes  Margarida Pinho-Lopes 《Geotechnical and Geological Engineering》2003,21(2):129-147

A geogrid reinforced steep slope was built and monitored during construction and during the first ten months of service. The slope is located between Régua and Reconcos in the new Portuguese main itinerary, IP3, and is a part of reestablishment 2. The reinforced slope has an extension of about 206.2m, is in curve and the reinforced area reaches a maximum height of about 19.6m in the outside curve slope at 150.0m of extension (km 0+150). The monitored slope cross section is at km 0+150. The reinforcements are high density polyethylene geogrids;. materials with different tensile strength values were used. The reinforcement strains were measured at three reinforcement levels using linear extensometers. The soil vertical stresses were recorded using load cells. The internal horizontal displacements of the slope were recorded using two inclinometer tubes. The face displacements were recorded topographically in points spaced approximately 1.2m vertically along the face of the slope on the km 0+150 cross section. The reinforced slope behaviour was observed during a period of about 13 months, which includes three months of construction period. This way it was possible to obtain information about the slope behaviour during and after construction (the first 10 months of service). The behaviour of the observed reinforced slope is characterized by: low values of face displacements, slope internal horizontal displacements and reinforcement strains; change of the face displacements configuration at the end of construction during service;tendency to stabilization of the horizontal displacements in a relatively short period of service; change, during service, of the position of the line passing through the points of the reinforcements where maximum strains were recorded. The reinforced slope behaviour express the conservative design of Equilibrium Limit methods and encourage the research on new design methods for geosynthetic reinforced soil systems.  相似文献   

常德至张家界高速公路慈利段典型岩质边坡成生机理初探     

何瑛雄 《湖南地质》2003,22(1):47-50

在山区修建高速公路时,由于“高填深切”改变了自然条件下的地质营力,从而带来一系列的环境地质问题,尤以岩质边坡开花后的稳定问题突出,只有对自然岩质边坡进行深入的研究,才能更好地提出合理的人工边坡设计方案．而传统的岩质边坡分析方法多是定性的笼统地分析,对岩质边坡的成生机理难以做到具体的分析,许多地质现象无法解释．运用系统工程地质有关边坡变形渗流场的稳态坡形理论对常德至张家界高速公路慈利段的典型岩质边坡的成生机理及边坡开挖后的破坏机理进行了分析,为人工边坡的设计提供了可靠的依据．  相似文献   

长珲高速公路某边坡锚索受力分析及选型          下载免费PDF全文

刘士虎  卢文阁  于万富  徐志超 《探矿工程》2005,32(8):32-34

压力分散型锚索以其合理的受力机理及其在软弱土体中能更有效地发挥土体承载能力的优势取得了在本工程中的优选。主要介绍了该类型锚索的特点、作用机理和张拉程序，同时对工程的施工情况作了简述。  相似文献   

螺旋冲击回转钻进技术及其在边坡治理中的应用          下载免费PDF全文

吴璋  周新莉 《探矿工程》2005,32(3):33-35

以施工实践为基础，结合理论分析，提出了一种在岩土锚固工程施工中广泛应用的新型钻探工艺技术——螺旋冲击回转钻进技术。在总结其优点的基础上提出了尚待解决的工艺难题。  相似文献   

福建黄岗山东南坡气温的垂直变化   总被引：11，自引：0，他引：11  

郑成洋  方精云 《气象学报》2004,62(2):251-255

利用HOBOOnset自动温度记录仪于 2 0 0 1年 11月～ 2 0 0 2年 11月对福建黄岗山东南坡 7个地点的气温 ,间隔15min进行了连续观测。结果显示 :黄岗山年平均气温直减率为 0 .4 3℃ / 10 0m ;不同月份的直减率有差异 ,一般来说 ,冬季小 ,夏季大 ,其中 12月最小 (0 .2 6℃ / 10 0m) ,9月最大 (0 .5 6℃ / 10 0m)。平均最高气温沿海拔高度变化并非呈线性关系 ,表现为中海拔 (16 0 0m )数值最低 ,而平均最低气温沿海拔高度呈明显线性关系 ,直减率为0 .5 4℃ / 10 0m。最高温度沿海拔高度变化不明显。月平均的日较差沿着海拔高度变化呈“U”字形 ,中海拔月平均日较差值最低。日平均气温≥ 0℃ ,≥ 5℃和≥ 10℃的积温沿海拔高度呈线性关系 ,直减率几乎相同。≥ 10℃积温从低海拔至高海拔相差约 2 0 0 0℃ ,海拔每升高 10 0m稳定初日至终日 ,积温日期间隔平均减少 7d左右。  相似文献