大光包巨型滑坡的滑带特征及滑坡动力学响应机理研究

发布时间：2018-04-30 05:44

本文选题：隐伏断裂 + 地震滑坡地貌　；参考：《成都理工大学》2015年硕士论文

【摘要】：大光包巨型滑坡作为汶川地震最大的滑坡,其边界条件、形成机制、运动特征、构造背景、滑坡动力学响应等一直是研究者最为关心的问题。文章从多个方面入手,着重对研究区滑坡发育规律和演化特征以及大光包滑坡滑带特征和滑坡动力学响应机理等进行研究:从形成滑坡的边界断裂入手,对滑坡区构造演化过程提出总体认识;通过地震地貌的研究,从等时性和穿时性两个方面,总结出研究区地震滑坡的发育规律及其对黄洞子沟右岸支沟地形地貌演化的“贡献”;层内错动带对比分析和成因机制研究让我们对滑带岩体有了进一步认识;滑带和滑面岩体在地震滑坡形成过程中的损伤变形甚至变质作用为大型高速远程滑坡的研究提供了借鉴:沿滑坡后壁发育的四合天井断裂为汶川地震发震断裂北西侧的隐伏断裂,该断层在大光包巨型滑坡形成的前期为滑坡边界的形成提供了有利条件,滑坡区断裂做为隐伏断裂端部,其所积累的巨大应力可能为滑坡初始运动提供动力的同时与层内错动带一起对滑坡规模起到控制作用。基于对研究区内汶川地震崩滑体的详细调查发现:黄洞子沟右岸(大光包滑坡、老鹰岩滑坡、红石沟滑坡所在一侧)由汶川地震触发的崩、滑体数量和规模较之左岸大很多;通过典型剖面对比进一步发现研究区内地震地貌原地复发的证据(断层崩积楔);文章结合区内实例,采用将今论古的方法,推断出黄洞子沟右岸支沟演化与多期次的古地震滑坡事件相关;该研究说明古地震滑坡多期次原地复发对滑源区地貌演化有着重要意义,与此同时对阐明龙门山地区乃至其他地震多发区地形地貌的演化发展有着举足轻重的作用。大光包巨型滑坡滑带特征方面:将层内错动带典型剖面从上到下分为:碎裂岩层、粉质层、错动分异层、粘土层等四层,并针对对各个层位岩体成分、结构、发育部位等特征进行了较为详细是分层描述;针对性的将大光包滑坡的滑带成因模式分为相互穿插的五个过程;从宏观上来讲,错动面下部岩体距离错动面越近其错动程度越高,岩石越破碎;从微观角度看,离错动面越近错动程度越高的岩体其原生沉积结构保留越差,取而代之的则是碎裂化越发育。文章独创性的将滑坡动力学响应过程中新形成的岩石或矿物命名为滑坡生成岩,并结合多个实例对滑坡生成岩进行系统阐述。大光包巨型滑坡为具有典型高速远程特征的深层滑坡,其具备形成滑坡生成岩的内在和外在条件:滑体厚度巨大,且滑体在运动初期并未发生大规模解体,使得滑体在运动时滑面附近有着巨大的压力;滑带岩体为震旦系灯影组白云岩,而碳酸盐岩恰为较易发生变质的岩石,在200到300摄氏度的温度和一定的压力条件下即可让其发生变质。文章将大光包滑坡滑带岩体和粘土质成分在不发生熔融而形成的一般性滑坡变质岩与前人对滑坡玻化岩和滑带变质矿物或滑带岩体重新胶结形成滑坡角砾岩进行对比研究,形成了滑坡生成岩(矿物)体系。采用垂向对比、横向对比、纵向对比相结合的方式对大光包滑坡变质岩进行研究发现:滑面发生变质的部位其下部岩体也会不同程度变质,且变质程度随着离滑面距离的增大而减弱直到一定深度变质现象完全消失;横向对比显示,滑面高高程处岩体变质程度最低,中高程处岩体变质程度最高,低高程处岩体变质程度中等的现象,说明该高程区域在滑坡过程中所受温、压条件并不是按照理论值同等变化的。大光包滑坡变质岩沿滑坡方向(纵向)发育特征表现为:从滑坡后缘到滑坡前缘,滑面岩体变质程度越来越高。
[Abstract]:As the largest landslide in Wenchuan earthquake, the great Guang Bao landslide has been the most concerned problem for the researchers. In this paper, the development regularity and evolution characteristics of landslides in the study area, the characteristics of landslide belt and landslide movement in the great light packet and the landslide movement are discussed in this paper. The mechanical response mechanism is studied. Starting with the formation of the boundary fault of the landslide, the overall understanding of the tectonic evolution process of the landslide area is put forward, and the development law of the Seismic Landslides in the study area and the "contribution" to the landform and geomorphology evolution of the right bank of the yellow cave ditch are summed up from the two aspects of the isochronous and the timing of the seismic geomorphology. The contrastive analysis of the interlayer dislocation and the study of the genetic mechanism let us have a further understanding of the rock mass. The damage deformation and even metamorphism of the sliding and slippery rock masses in the formation of the Seismic Landslides provides a reference for the large and high speed long distance landslides. The four closing well fracture along the back wall of the landslide is a seismogenic fault in Wenchuan. The hidden fault in the north west side provides favorable conditions for the formation of the landslide boundary in the early stage of the great Guang Bao Mega landslide. The landslide zone fault is the end of the hidden fault. The accumulated huge stress may provide power for the initial landslide movement and control the scale of the landslide with the inner fault zone. The detailed investigation of Wenchuan earthquake avalanche in the study area has found that the number and scale of the slide body triggered by the Wenchuan earthquake is much larger than that on the left bank, which is triggered by the Wenchuan earthquake on the right bank of the Huangdong Zi gully (Dapu landslide, the Lao Ying rock landslide and the side of the Hongshi gully landslide). In combination with an example in the area, the article deduces that the evolution of the right bank branch gully evolution in the Yellow Dong Zi gully is related to the multi period paleoseismic landslide, which shows that the recurrence of the ancient earthquake landslides is of great significance to the landform evolution in the skid source area, and it also illustrates the Longmen mountain area and the other earthquakes at the same time. The evolution and development of topography and geomorphology in the development area have played an important role. In the aspect of the great Guang Bao landslide belt, the typical section of the inner fault zone is divided into four layers, such as fractured rock layer, silty layer, fault differentiation layer, clay layer and so on. The stratified description is divided into five processes in which the sliding zone of the great light packet landslide is divided into each other. From the macro point of view, the closer to the dislocation surface, the higher the fault movement and the more fractured rock, and from the micro point of view, the worse the rock mass with the higher the error moving range is, the worse the reservation of the primary sedimentary structure. The new rock or mineral formed in the process of the dynamic response of the landslide is named landslide generation rock, and the landslide generation rock is systematically expounded in combination with several examples. The huge landslide is a deep landslide with typical high speed and remote characteristics, which has the formation of landslide generation rock. The internal and external conditions are: the thickness of the slide body is huge and the slide body does not disintegrate in a large scale at the beginning of movement, which makes the sliding body have great pressure near the sliding surface, and the slide rock is the dolomite in the Sinian Dengying group, and the carbonate rocks are just the more prone to metamorphic rocks at 200 to 300 degrees Celsius and a certain pressure bar. In this paper, the general landslide metamorphic rocks, which are formed in the absence of melting, have been contrasted with the predecessors to form landslide breccia by cementing landslide vitrified rock, sliding belt metamorphic mineral or slide rock mass, and forming a landslide formation rock (mineral) system. The vertical contrast, lateral contrast and longitudinal contrast are combined to study the metamorphic rock of Da Guang Bao landslide. It is found that the lower rock mass of the metamorphic part of the sliding surface will also deteriorate in varying degrees, and the degree of metamorphism weakens with the distance from the sliding surface to a certain depth to a certain depth, and the lateral contrast shows that the sliding surface is high. The rock metamorphism of the rock mass is the lowest, the rock metamorphic degree at the middle elevation is the highest and the rock metamorphic degree of the low elevation is moderate, which indicates that the temperature of the elevation area is not the same as the theoretical value. The development characteristics of the Da Guang Bao landslide along the landslide direction (longitudinal) are manifested in the back edge of the landslide to the landslide. In the front of the landslide, the metamorphic degree of the sliding surface rock is getting higher and higher.

【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P642.22

【参考文献】