堆积斜坡地震响应机理分析——以四川茂县国际饭店滑坡为例
|
摘要
地震作用下堆积斜坡的动力响应是十分复杂的过程。为了研究地震条件下堆积斜坡的响应机理,以茂县国际饭店滑坡为例,通过现场调查堆积斜坡发育特征,借助二维颗粒流程序PFC~(2D)研究了地震动力作用下堆积斜坡位移响应特征和速度响应特征,以此对其失稳机理进行研究。结果表明:堆积斜坡动力响应具有一定的滞后性,且在失稳初期具有启动加速效应;在水平方向和竖直方向上速度响应均有放大效应,且水平放大效应较竖直放大效应更加显著。茂县国际饭店堆积斜坡地震响应机理为:地震峰值加速度增加—后缘先产生裂缝并迅速拉裂—裂隙加速发育并形成沿堆积层和基岩交界面贯通的滑面加速下滑—受颗粒间碰撞耗能作用及刮铲耗能影响最终停止运动。深切河谷地区堆积斜坡地震响应机理为:后缘拉裂—滑面贯通—加速下滑—解体、局部抛射—颗粒碰撞、刮铲—堆积。研究成果可为深切河谷地区类似堆积斜坡失稳机理分析提供参考。
The dynamic response of a stacked slope under earthquakes is a very complex process. In order to study the response mechanism of deposit slope under seismic condition, the displacement response and velocity response of deposit slope under dynamic seismic effect are studied herein with the 2-D particle flow program PFC~(2 D) through the site investigation of the development characteristics of deposit slope by taking the Landslide of Maoxian International Hotel as a case, so as to study its instability mechanism. The result shows that the dynamic response of deposit slope has a certain hysteretic property and starting acceleration effect; for which the velocity responses in both the horizontal direction and vertical direction have amplification effects, while the horizontal amplification effect is more significant than that of the vertical one. The slope seismic response mechanism of Maoxian International Hotel is that the peak seismic acceleration increases—the back edge cracks at first and then pulls apart—the crack acceleratedly develops and forms the accelerated downward slide of the slipping plane throughout the bedrock interface and along the deposit layer—the movement finally stops under the energy consumption effect from the collision among particles and the influence from the energy consumption of scraping-spading effect. The seismic response mechanism of the deposit slope in the region of deep-cut valley is that the tensile cracking of back edge—cutthrough of slipping plane—accelerated downward slide—disintegration and local casting—collision among particles and scraping-spading—deposition. The study result can provide references for the analysis made on the instability mechanism of the similar deposit slope in deep-cut valley.
The dynamic response of a stacked slope under earthquakes is a very complex process. In order to study the response mechanism of deposit slope under seismic condition, the displacement response and velocity response of deposit slope under dynamic seismic effect are studied herein with the 2-D particle flow program PFC~(2 D) through the site investigation of the development characteristics of deposit slope by taking the Landslide of Maoxian International Hotel as a case, so as to study its instability mechanism. The result shows that the dynamic response of deposit slope has a certain hysteretic property and starting acceleration effect; for which the velocity responses in both the horizontal direction and vertical direction have amplification effects, while the horizontal amplification effect is more significant than that of the vertical one. The slope seismic response mechanism of Maoxian International Hotel is that the peak seismic acceleration increases—the back edge cracks at first and then pulls apart—the crack acceleratedly develops and forms the accelerated downward slide of the slipping plane throughout the bedrock interface and along the deposit layer—the movement finally stops under the energy consumption effect from the collision among particles and the influence from the energy consumption of scraping-spading effect. The seismic response mechanism of the deposit slope in the region of deep-cut valley is that the tensile cracking of back edge—cutthrough of slipping plane—accelerated downward slide—disintegration and local casting—collision among particles and scraping-spading—deposition. The study result can provide references for the analysis made on the instability mechanism of the similar deposit slope in deep-cut valley.
引文
[1] 王自高,胡瑞林,张瑞,等.大型堆积体岩土力学特性研究[J].岩石力学与工程学报,2013,32(S2):3836- 3843.
[2] 邓天鑫,巨能攀,李龙起,等.陡倾顺层岩质斜坡动力倾倒变形机理研究[J].水利水电技术,2017,48(12):146- 152.
[3] 甘建军,吴晗,黄润秋,等.汶川地震区典型堆积体成灾模式研究[J].灾害学,2013,28(4):40- 44.
[4] 许强.汶川大地震诱发地质灾害主要类型与特征研究[J].地质灾害与环境保护,2009,20(2):86- 93.
[5] 许强,黄润秋.5.12汶川大地震诱发大型崩滑灾害动力特征初探[J].工程地质学报,2008,16(6):721- 729.
[6] 王运生,徐鸿彪,罗永红,等.地震高位斜坡形成条件及抛射运动程式研究[J].岩石力学与工程学报,2009,28(11):2360- 2368.
[7] 张华,游宏,陆阳.地震作用下斜坡堆积体的变形规律[J].公路交通科技,2014,31(1):50- 54.
[8] 王宇,贾洪彪,赵轩,等.地震作用下均质土坡动力特性的振动台试验研究[J].地震工程学报,2017,39(1):100- 106.
[9] 刘婧雯,黄博,邓辉,等.地震作用下堆积体边坡振动台模型试验及抛出现象分析[J].岩土工程学报,2014,36(2):307- 311.
[10] 孙志亮,孔令伟,郭爱国.风干堆积体边坡地震响应的动力离心模型试验[J].岩石力学与工程学报,2017,36(9):2102- 2112.
[11] 孙志亮,孔令伟,郭爱国,等.地震作用下堆积体边坡的坡面变形与失稳机制[J].岩土力学,2015(12):3465- 3472.
[12] 杨庆华,姚令侃,杨明.地震作用下松散堆积体崩塌的颗粒流数值模拟[J].西南交通大学学报,2009,44(4):580- 584.
[13] SASSA K,FUKUOKA H,SCARASCIA-MUGNOZZA G,et al.Earthquake-induced landslides,Distribution,motion and mechanisms[J].Soils & Foundations,2014,54(4):544- 559.
[14] ROBACK K,CLARK M K,WEST A J,et al.The size,distribution,and mobility of landslides caused by the 2015 Mw 7.8 Gorkha earthquake,Nepal[J].Geomorphology,2018,29(3):26- 43.
[2] 邓天鑫,巨能攀,李龙起,等.陡倾顺层岩质斜坡动力倾倒变形机理研究[J].水利水电技术,2017,48(12):146- 152.
[3] 甘建军,吴晗,黄润秋,等.汶川地震区典型堆积体成灾模式研究[J].灾害学,2013,28(4):40- 44.
[4] 许强.汶川大地震诱发地质灾害主要类型与特征研究[J].地质灾害与环境保护,2009,20(2):86- 93.
[5] 许强,黄润秋.5.12汶川大地震诱发大型崩滑灾害动力特征初探[J].工程地质学报,2008,16(6):721- 729.
[6] 王运生,徐鸿彪,罗永红,等.地震高位斜坡形成条件及抛射运动程式研究[J].岩石力学与工程学报,2009,28(11):2360- 2368.
[7] 张华,游宏,陆阳.地震作用下斜坡堆积体的变形规律[J].公路交通科技,2014,31(1):50- 54.
[8] 王宇,贾洪彪,赵轩,等.地震作用下均质土坡动力特性的振动台试验研究[J].地震工程学报,2017,39(1):100- 106.
[9] 刘婧雯,黄博,邓辉,等.地震作用下堆积体边坡振动台模型试验及抛出现象分析[J].岩土工程学报,2014,36(2):307- 311.
[10] 孙志亮,孔令伟,郭爱国.风干堆积体边坡地震响应的动力离心模型试验[J].岩石力学与工程学报,2017,36(9):2102- 2112.
[11] 孙志亮,孔令伟,郭爱国,等.地震作用下堆积体边坡的坡面变形与失稳机制[J].岩土力学,2015(12):3465- 3472.
[12] 杨庆华,姚令侃,杨明.地震作用下松散堆积体崩塌的颗粒流数值模拟[J].西南交通大学学报,2009,44(4):580- 584.
[13] SASSA K,FUKUOKA H,SCARASCIA-MUGNOZZA G,et al.Earthquake-induced landslides,Distribution,motion and mechanisms[J].Soils & Foundations,2014,54(4):544- 559.
[14] ROBACK K,CLARK M K,WEST A J,et al.The size,distribution,and mobility of landslides caused by the 2015 Mw 7.8 Gorkha earthquake,Nepal[J].Geomorphology,2018,29(3):26- 43.