康定县孔玉乡寸达河坝后山Ⅰ区危岩崩塌发育特征及其防治措施研究

发布时间：2018-04-06 06:05

本文选题：危岩体　切入点：稳定性　出处：《西南交通大学》2017年硕士论文

【摘要】：康定县孔玉乡寸达河坝后山危岩带位于康定县孔玉乡政府后山,该危岩区裂隙发育、岩体完整性较差。近两年受2013年4.20芦山地震和强降雨影响,崩塌区危岩体变形加剧,表层多有危岩体脱离母岩而发生崩落,对坡下孔玉乡政府所在地的人民生命财产安全和过往车辆都构成严重威胁。本文在掌握研究区地下水、风化卸荷、地层岩性、地形地貌等地质条件的基础上,全面查明了危岩体空间分布及可能的失稳模式和分类,对不同的危岩体进行了稳定性分析以及危岩可能崩塌后各阶段运动特征计算,最终提出了针对性的工程治理措施。本文的主要研究成果如下:(1)研究区岩性为白云岩,节理较发育,且坡度陡峭,有利于崩塌落石发育。通过对影响危岩崩塌发育的因素分析,总结出研究区危岩发生崩塌落石的主要因素有如下两类。内在因素主要包括:研究区地形地貌和岩体自身岩性及结构;外在因素主要包括:降雨和地下水作用、地震作用、风化作用、重力作用、人类活动和植物根劈等。(2)根据大量的现场勘察资料,结合国内外对危岩失稳模式的分类,将研究区的危岩失稳分为三种模式:滑移式、倾倒式和坠落式。分别对三种失稳模式下的危岩体利用赤平投影对其稳定性进行定性分析,然后建立模型,通过定量计算进行其稳定性分析。(3)采用离散元分析软件UDEC模拟分析不同裂隙水压力作用下危岩的稳定性情况。通过对不同高度裂隙水的控制模拟,可以得知裂隙水对危岩体产生挤压破坏,使得危岩裂隙不断扩张;在强降雨或暴雨作用下,因为裂隙水压力增大,使危岩体裂隙法向压力不断增大,所以危岩结构面不断扩张,最后导致崩塌落石。(4)引用前辈学者们对崩塌落石运动过程的研究分析,判断出研究区危岩崩落后各个运动阶段的特征。根据现场存留的一些落石运动痕迹,结合研究资料,推测出研究区以往发生崩塌落石的运动轨迹和运动特征,然后运用Rockfall软件对研究区落石的运动轨迹和特征进行反演模拟计算,其计算结果可以为之后的防治措施提供针对性的基础力学参数。(5)在对已有危岩崩塌各类防治措施及其适用性进行总结的基础上,根据研究区危岩体空间分布、可能崩落路径的地形地貌特征,结合崩塌落石运动特征和保护对象位置,针对危岩带I W1的严重性和危害性较大建议采用主动防治措施,其他危岩体进行被动防护。
[Abstract]:The Houshan dangerous rock belt of Cunda River Dam in Kongyu Township of Kangding County is located in Houshan Mountain of Kongyu Township Government in Kangding County. The fissure in this dangerous rock area is developed and the integrity of rock mass is poor.Affected by the Lushan earthquake of 4.20 2013 and heavy rainfall in recent two years, the deformation of dangerous rock mass in the collapse area is aggravated, and most of the dangerous rock mass in the surface surface caving away from the parent rock.It poses a serious threat to the people's lives, property and vehicles in the government seat of Kongyu Township.On the basis of mastering the geological conditions such as groundwater, weathering unloading, stratigraphic lithology, landform and geomorphology in the study area, the spatial distribution of dangerous rock mass and its possible instability model and classification are found out in this paper.The stability analysis of different dangerous rock mass and the calculation of the movement characteristics of each stage after the possible collapse of the dangerous rock mass are carried out. Finally, the corresponding engineering treatment measures are put forward.The main research results of this paper are as follows: (1) the lithology of the study area is dolomite, the joints are relatively developed, and the slope is steep, which is conducive to the development of collapse and falling stone.Based on the analysis of the factors affecting the development of dangerous rock collapse, the main factors of collapse and falling of dangerous rock in the study area are summarized as follows.Internal factors mainly include: topography, geomorphology and rock mass lithology and structure in the study area; external factors mainly include: rainfall and groundwater, earthquake, weathering, gravity,Based on a large number of field survey data and the classification of unstable models of dangerous rock at home and abroad, the unstable rock instability in the study area can be divided into three types: slip type, toppling type and falling type.The stability of dangerous rock mass under three unstable modes is analyzed qualitatively by using stereographic projection, and then the model is established.The stability of dangerous rock under different fissure water pressure is simulated by using discrete element analysis software UDEC.By controlling and simulating the fractured water at different heights, it can be known that the fractured water produces compressive damage to the dangerous rock mass, which causes the crack to expand continuously, and under the action of heavy rainfall or rainstorm, the pressure of the fissure water increases.The normal pressure of fracture in dangerous rock is increasing constantly, so the structure plane of dangerous rock is expanding, which leads to the collapse and falling stone. 4) citing the previous scholars' research and analysis on the process of collapse and falling stone,The characteristics of dangerous rock avalanche lagging behind each movement stage in the study area are judged.On the basis of some trace of rock falling movement left in the field, combined with the research data, we infer the movement track and motion characteristics of the rock collapse in the past in the study area.Then the motion trajectory and characteristics of rock fall in the study area are simulated by using Rockfall software.The calculated results can provide the relevant basic mechanics parameters for the prevention and control measures. On the basis of summarizing the various prevention measures and their applicability of the existing dangerous rock collapse, according to the spatial distribution of the dangerous rock mass in the study area,According to the topographic and geomorphological characteristics of the possible caving path, combined with the movement characteristics of the collapse and falling rock and the location of the protected objects, active prevention measures should be adopted in view of the severity and harmfulness of IW1 in the dangerous rock zone, and other dangerous rock masses should be passively protected.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P642.21

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