则木河断裂带大箐断层活动性及致灾效应研究

发布时间：2018-04-24 17:28

本文选题：则木河断裂带 + 地质灾害　；参考：《成都理工大学》2017年硕士论文

【摘要】：则木河断裂带位于青藏高原东南缘─川滇菱形地块东边界转折部位,为一大型左旋走滑继承性活动断裂。因其所处的特殊构造位置、强烈的地壳形变与断裂活动,具有地质条件复杂、地震活动强烈、次生地质灾害严重的特点。为了给则木河断裂带沿线城镇地质灾害防治、工程建设规划和断裂灾害研究提供科学依据,本文以次级断裂中活动性最强的大箐断层为例,通过遥感解译、现场调查和科学分析,探讨了断裂的活动特征及其对地质环境演化控制效应,断裂带地质灾害效应和长期活动性以及断裂致灾效应,取得如下成果:(1)则木河断裂带对地质环境控制效应。(1)新构造运动与地震控制效应:则木河断裂带强烈继承左旋走滑运动成为区域性现代地壳活动带,往往控制区域构造活动和地震的形成分布,使其成为则木河地震活动带。(2)地形地貌控制效应:以断裂带为联系纽带,通过上升、陷落和反翘差异性运动,塑造了截然不同的隆起断块山、断陷河谷和拉分盆地三种断块活动单元。(3)古地理沉积环境控制效应:沉降带或沉降断块形成复杂多变、松散软弱的新沉积层,而隆起断块则遭受侵蚀、剥蚀形成松散风化带,此外断裂沿线形成宽1-2km的断层构造破碎带,为各种地质灾害作用提供物质来源和条件。(4)地表水系格局和地热运移控制效应:断裂枢纽掀斜和左旋走滑运动,形成四象地貌改变地表水系格局,通过断裂带形成深层地热场向地表运移、循环的通道,构成地下水富集强径流带。(5)地质作用演化控制效应:则木河断裂带通过影响区域地质环境的演化,诱发巨量地震次生地质灾害加剧地表过程,最终由地震构造作用驱动的隆起和断陷,以及地表灾害过程驱动的剥蚀和淤积,两者相互作用决定现有地貌演化。(2)大箐断层活断裂地质灾害控制效应。(1)地质灾害发育特征:具有显著的断裂控制特征,断裂活动通过加剧地质环境恶化,为灾害发育提供物质结构基础和地貌条件,从而影响灾害边界特征、变形破坏过程和后期演化,成为控制地质灾害的主导因素。(2)地质灾害分布规律:具有断裂灾害时空效应,即控制灾害的空间分布和长期活动性。空间8大效应:断裂距离效应(带状分布)、烈度效应(衰减型)、西盘效应、斜坡结构效应(软弱面)、水系效应(线状分布)、微地貌效应(高程、坡度、坡型)、构造应力场效应,地层倾向性(集中断裂破碎带)。时间8种特征,表现为地质灾害的长期活动性:崩滑灾害频发性、复活性、期次性和扩展性,泥石流灾害的活跃性、高频性、侵蚀淤积性和持续性。(3)大箐断层致灾效应。则木河断裂活动影响灾害成因机制,变形破坏模式和灾害链式效应。(1)致灾模式:依据地质条件,斜坡动力响应特征和失稳破坏形式的差异,分为岩崩、碎屑型、碎屑坡面流型3类崩塌,古地震型、震裂型、堆积层型3类滑坡,高位坡面型、沟谷暴雨型2类泥石流,共崩、滑、流3大种,8亚类,15小类。(2)断裂致灾机制:则木河断裂带构造活动对区域地质背景和灾害格局起决定和控制作用;断裂形成演化过程中提供物质结构和地形基础,在强震主导下地质环境持续恶化,地震触发累计变形效应显著,特别是在后期临近中弱地震频繁持续的扰动、极端降雨入渗的耦合作用,频繁强烈的人类工程活动作用,成为促使灾害频发的根本原因。(3)断裂灾害链式效应:断裂带具有良好的灾害链式效应,其类型分为单沟、主沟和复合型3种10类,激发因素为地震+降雨,演化过程为崩滑─泥石流─洪积扇(浊流),损毁特征为人财损失+工程毁坏+环境恶化。灾害链式演化模式概化为:地质环境孕育─冰川运动及邛海群沉积─地震破裂带古滑坡形成段─震后地质灾害频发─链式灾害演化衰退共5个阶段。断裂带灾害链式效应是一个时空扩展强、类型全、规模大、环境机理复杂的灾害群体系,必须形成一个长期、系统、全面、实时的综合防治系统。龙门山和则木河断裂带致灾效应有其相似性和差异性,前者会向后者逐渐过渡和转化,因而本文可为汶川地震灾害规划防治科学研究提供参考。
[Abstract]:It is located in the turning part of the eastern border of the southeast of the Qinghai Tibet Plateau and the east boundary of the Sichuan Yunnan rhombus block. It is a large left lateral strike slip fault. Because of its special tectonic position and strong crustal deformation and fracture activity, the geological conditions are complex, the seismic activity is strong and the secondary geological disaster is serious. It provides scientific basis for the prevention and control of geological disasters along the river fault zone, the planning of engineering construction and the study of fracture disaster. In this paper, taking the Daqing fault with the strongest activity in the secondary fracture as an example, through the interpretation of remote sensing, field investigation and scientific analysis, the characteristics of the fault activity and its control effect on the geological environment evolution and the geological disaster of the fault zone are discussed. The results are as follows: (1) the control effect of the wooden river fault zone on the geological environment. (1) the neotectonic movement and the seismic control effect: the strong inheritance of the left slip movement into a regional modern crustal zone, and often control the regional tectonic activity and the distribution of earthquakes. To make it become the seismic activity belt of the Mu He. (2) the control effect of topography and geomorphology: Taking the fault zone as the link, through the difference movement of rising, falling and anti warping, it has created a totally different uplift fault block mountain, the rift valley and the pull apart basin three kinds of block activity units. (3) the paleogeographic sedimentary environment control effect: settlement zone or settlement block formation The complex, loose and weak new sedimentary layer, while the uplift fault block is eroded, the denudation forms the loose weathering zone, and the fault tectonic zone of wide 1-2km is formed along the fault, which provides material sources and conditions for various geological disasters. (4) the surface water system pattern and the control effect of geothermal migration: fracture hinge tilting and left-hand slip movement The formation of the surface water system is formed by the formation of the four image geomorphology, and the deep geothermal field is formed through the fracture zone to move to the ground surface, and the circulation channel is formed to enrich the strong runoff zone of the groundwater. (5) the effect of the geological evolution control. Finally, the uplift and fault depression driven by seismic tectonic action and the erosion and deposition driven by the surface disaster process determine the evolution of the existing geomorphology. (2) the control effect of the geological disaster of the Daqing fault active fault. (1) the characteristics of the geological hazard development: the characteristics of significant fracture control and the deterioration of the fault activity through the aggravation of the geological environment, Disaster development provides material structure basis and geomorphic conditions, thus affecting the characteristics of disaster boundary, deformation and failure process and later evolution, and become the leading factors to control geological disasters. (2) the distribution law of geological disasters: the space-time effect of the fracture disaster, that is, the spatial distribution and long-term activity of controlling the disaster. The 8 big effect of space: the fault distance effect Should (band distribution), intensity effect (attenuation), West disk effect, slope structure effect (weak surface), water system effect (linear distribution), microgeomorphic effect (elevation, slope, slope type), tectonic stress field effect, stratigraphic tendency (concentrated fracture zone). Time 8 characteristics are characterized by long-term activity of geological disasters: frequent occurrence and resurrection of landslide disaster. Duration and expansibility, activity of debris flow, high frequency, erosion silt and continuity. (3) the effect of Daqing fault. The mechanism of formation, deformation and failure mode and chain effect are affected by the activity of the tree river fault. (1) the pattern of disaster caused by the geological strip, the difference of the dynamic response characteristics of the slope and the form of instability and failure. Rock avalanche, detrital and clastic slope flow pattern 3 types of collapse, paleo seismic type, earthquake crack type, accumulation layer type 3 types of landslides, high slope face type, and gully rainstorm type 2 types of debris flow, common avalanche, slide, flow 3 species, 8 subcategory, 15 small category. (2) fracture mechanism: the structural activity of the timber River fault zone determines and controls the regional geological background and disaster pattern; fracture shape In the process of evolution, the material structure and the terrain foundation are provided, and the geological environment continues to deteriorate under the strong earthquake, and the cumulative deformation effect of the earthquake triggers is remarkable, especially the frequent and continuous disturbances in the later period near the middle and weak earthquakes, the coupling action of extreme rainfall infiltration, and the frequent and intense human engineering activity, which has become the fundamental of the frequent disasters. (3) the chain effect of fracture disaster: the fracture zone has good chain effect of disaster, and its types are divided into 3 kinds, single gully, main ditch and compound type, and the excitation factors are earthquake + rainfall, the evolution process is landslide - debris flow - Hong Jishan (Zhuo Liu), the damage characteristic is human loss and loss + engineering destruction + environment deterioration. The disaster chain evolution model is generalized as follows: The geological environment is pregnant with the 5 stages of the glacial movement and the formation of the qiqiqihai group, the paleo landslide formation section of the Qiong sea group, the formation of the ancient landslides in the earthquake rupture zone - the frequent occurrence of the chain type disaster evolution after the earthquake. The disaster chain effect of the fault zone is a disaster group system with strong space-time expansion, full type, large scale and complex environmental mechanism, which must form a long-term, systematic and whole system. The effect of the Longmen mountain and the Reihe River fault zone has its similarity and difference, and the former will gradually transition and transform to the backward. Therefore, this paper can provide reference for the scientific research on the prevention and control of earthquake disaster in Wenchuan.

【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P694;P315

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