龙门山北段飞凤山地区构造变形特征及对场地稳定性的影响
发布时间：2018-08-06 12:19
【摘要】：近几年龙门山地震频发,特别是2008年汶川地震,由于地震强度大,震源浅,烈度大,影响范围波及大半个中国,导致在超过10万km2的范围内产生了重大的人员和财产损失,这是新中国成立以来破坏性最强、波及范围最大的一次地震。对龙门山断裂带区域地质及地质稳定性产生了重要影响。而飞凤山地区正处于龙门山断裂带北段,是扬子板块、松潘地块和祁连—秦岭造山带系的交界处。从北西到南东可划分为龙门山中央推覆带、龙门山前陆推覆带和四川盆地三个Ⅲ级构造单元。受多个地质单元构造活动影响,研究区处于活动区域的边缘,多期次多阶段受到不同方向力的作用,使得研究区的构造较为复杂。针对场地地质稳定性问题,本研究课题将为场地稳定性评价和加固提供技术支撑,对保证场地安全具有重要意义;同时部分理论研究上的突破,对同类工程的处置具有重要参考和指导意义。在运用构造地质学的技术方法,宏观掌握飞凤山地区以及邻近区域的研究进展和成果上,通过野外地质调查和分析该地区有关的地层、构造以及测年数据等方面的研究成果,对该地区构造的几何学特征、运动学特征、构造组合特征进行详细的研究,对地区构造的动力学机制有一个初步的认识,进而对该地区的构造演化史进行研究。通过对飞凤山地区的野外实际地质调查工作,以及室内构造数据的整理分析,明确了飞凤山地区的构造单元特征以及应力演化序列,飞凤山地区在构造轮廓形成之后,还经历了多期应力,逐渐形成了现在的构造形态。在系统总结前人研究成果的基础上,通过野外地质调查和室内资料的整理分析,对于飞凤山地区构造特征及其演化得出了如下认识:第一期为平面X节理及褶皱形成,来自NW-SE应力;第二期为断层走滑性质,受N-S方向主应力;第三期褶皱及逆冲断层形成,受NE-SW应力;第四期节理密集带形成,早期逆冲性质,受E-W向主应力;第五期为拉张应力,主要表现N-S向X节理有正断性质;第六期小断层走滑性质,受NW-SE主应力。从工程地质分析的实际需要出发,认为其中对场地影响较大的主要有下列几组:一、近W-E向陡倾断层及节理密集带近W-E向陡倾断层绝大多数为构造角砾岩带,角砾岩固结坚硬,焊接两盘。少数含断层泥者从上述测年数据看无晚更新世以来的活动。节理密集带充填两期方解石脉,无第四纪活动迹象。二、近N-S向节理密集带宏观观察场地近N-S向节理密集带为脆-韧性变形产物:带内两条节理间为复杂的揉皱构造,节理面上留下擦痕及方解石拉伸线理。场地外回滩子的小断层的晚更新世活动释放了场地内同方向构造的构造应力。回滩子的晚更新世活动因为出现在泥岩中,判断其为蠕滑活动而非粘滑活动,因此对场地稳定性影响不大。三、顺层错动带或泥化夹层带顺层错动带或泥化夹层带有一定的活动性,活动点分布零星。表明晚更新世以来顺层滑动出现过,但未出现贯穿性大规模活动。
[Abstract]:In recent years, Longmen Mountain earthquake occurred frequently, especially in the Wenchuan earthquake of 2008. Due to the large earthquake intensity, shallow seismic source and high intensity, the impact range has been affected by more than half of China, resulting in great loss of personnel and property in the range of more than 100 thousand Km2. This is the most devastating and most widespread earthquake in Longmen since the founding of new China. The mountain fault zone has an important influence on the regional geology and geological stability, while the Fengshan area is located in the northern part of the Longmen Mountain Fault Zone, which is the junction of the Yangzi plate, the Songpan block and the Qilian Qinling Mountains orogenic belt system. From the North West to the South East, it can be divided into the central nappe zone of the Longmen mountain, the cladding belt of the Longmen in front of the mountain and the three third grade structures in the Sichuan basin. Affected by the tectonic activities of multiple geological units, the research area is on the edge of the active area, and the multi phase and multi stage is affected by different direction forces, which makes the structure of the research area more complex. In view of the problem of site geological stability, this research project will provide technical support for the evaluation and reinforcement of site stability and guarantee site safety. It is of great significance; at the same time, the breakthrough in some theoretical research has important reference and guiding significance for the disposal of similar projects. In the use of the technical methods of tectonic geology, the research progress and results of the Fengshan area and adjacent areas are mastered, and the related strata, structures and measurements in the area are investigated and analyzed by field geological investigation and analysis. The research results of the annual data, such as the geometric features of the region, the kinematic characteristics and the structural combination features, have a detailed understanding of the dynamic mechanism of the regional tectonics, and then study the tectonic evolution history of the region, and through the field investigation of the field in the Fengshan area, and According to the analysis of the indoor structural data, the characteristics of the tectonic units and the sequence of stress evolution in the Fengshan area have been clarified. After the formation of the tectonic outline, the Fengshan region has also experienced multiple periods of stress and gradually formed the present structural form. On the basis of the systematic summary of the previous research results, the field geological survey and the indoor data are carried out. The analysis shows the following understanding of the structural characteristics and evolution of the Fengshan area: the first phase is plane X joints and folds, from NW-SE stress, the second phase is fault strike slip, the main stress in N-S direction, the third fold and thrusting faults, the NE-SW stress, the fourth stage dense zone, and the early thrusting properties, E- W is the main stress; the fifth stage is tensile stress, which mainly shows that N-S has a positive fault to X joints, and the sixth small fault strike slip property is subject to the main stress of the engineering geological analysis. In most of the tectonic breccia belts, breccia is consolidated and hard, and two plates are welded. A few of the gouges have no late Pleistocene activities from the above data. The two phase of the calcite veins filled with the jointed zone have no signs of Quaternary activity. Two, near N-S to the macroscopic observation site near the joint dense zone is brittle ductile deformation. The two joints in the belt are complex crumpled structures, and the joints leave scratches and calcite stretching lines. The late Pleistocene activities of the small faults in the back of the field released the tectonic stress in the same direction in the site. The late Pleistocene activity of the back beach was judged to be a creep rather than a stick slip activity in the mudstone. Therefore, there is little effect on the stability of the site. Three, the bedding dislocation belt or the muddy interlayer with a bedding dislocation or muddy interlayer has a certain activity, and the distribution of the active point is scattered. It shows that the bedding slip has appeared since the late Pleistocene, but there is no penetrating large-scale activity.
【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】：P315.2
本文编号：2167711
[Abstract]:In recent years, Longmen Mountain earthquake occurred frequently, especially in the Wenchuan earthquake of 2008. Due to the large earthquake intensity, shallow seismic source and high intensity, the impact range has been affected by more than half of China, resulting in great loss of personnel and property in the range of more than 100 thousand Km2. This is the most devastating and most widespread earthquake in Longmen since the founding of new China. The mountain fault zone has an important influence on the regional geology and geological stability, while the Fengshan area is located in the northern part of the Longmen Mountain Fault Zone, which is the junction of the Yangzi plate, the Songpan block and the Qilian Qinling Mountains orogenic belt system. From the North West to the South East, it can be divided into the central nappe zone of the Longmen mountain, the cladding belt of the Longmen in front of the mountain and the three third grade structures in the Sichuan basin. Affected by the tectonic activities of multiple geological units, the research area is on the edge of the active area, and the multi phase and multi stage is affected by different direction forces, which makes the structure of the research area more complex. In view of the problem of site geological stability, this research project will provide technical support for the evaluation and reinforcement of site stability and guarantee site safety. It is of great significance; at the same time, the breakthrough in some theoretical research has important reference and guiding significance for the disposal of similar projects. In the use of the technical methods of tectonic geology, the research progress and results of the Fengshan area and adjacent areas are mastered, and the related strata, structures and measurements in the area are investigated and analyzed by field geological investigation and analysis. The research results of the annual data, such as the geometric features of the region, the kinematic characteristics and the structural combination features, have a detailed understanding of the dynamic mechanism of the regional tectonics, and then study the tectonic evolution history of the region, and through the field investigation of the field in the Fengshan area, and According to the analysis of the indoor structural data, the characteristics of the tectonic units and the sequence of stress evolution in the Fengshan area have been clarified. After the formation of the tectonic outline, the Fengshan region has also experienced multiple periods of stress and gradually formed the present structural form. On the basis of the systematic summary of the previous research results, the field geological survey and the indoor data are carried out. The analysis shows the following understanding of the structural characteristics and evolution of the Fengshan area: the first phase is plane X joints and folds, from NW-SE stress, the second phase is fault strike slip, the main stress in N-S direction, the third fold and thrusting faults, the NE-SW stress, the fourth stage dense zone, and the early thrusting properties, E- W is the main stress; the fifth stage is tensile stress, which mainly shows that N-S has a positive fault to X joints, and the sixth small fault strike slip property is subject to the main stress of the engineering geological analysis. In most of the tectonic breccia belts, breccia is consolidated and hard, and two plates are welded. A few of the gouges have no late Pleistocene activities from the above data. The two phase of the calcite veins filled with the jointed zone have no signs of Quaternary activity. Two, near N-S to the macroscopic observation site near the joint dense zone is brittle ductile deformation. The two joints in the belt are complex crumpled structures, and the joints leave scratches and calcite stretching lines. The late Pleistocene activities of the small faults in the back of the field released the tectonic stress in the same direction in the site. The late Pleistocene activity of the back beach was judged to be a creep rather than a stick slip activity in the mudstone. Therefore, there is little effect on the stability of the site. Three, the bedding dislocation belt or the muddy interlayer with a bedding dislocation or muddy interlayer has a certain activity, and the distribution of the active point is scattered. It shows that the bedding slip has appeared since the late Pleistocene, but there is no penetrating large-scale activity.
【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】：P315.2
【参考文献】
相关期刊论文 前2条
1 马杏垣;;中国岩石圈动力学概要[J];地质学报;1987年02期
2 周建文,曾庆,徐世琦,李毅,洪海涛,宋明伟,胡恒智,何智慧;龙门山北段推覆构造带变形特征研究[J];天然气工业;2005年S1期
，本文编号：2167711
本文链接：https://www.wllwen.com/kejilunwen/diqiudizhi/2167711.html
