红石岩水利枢纽岸坡崩塌发育特征与稳定性评价研究

发布时间：2018-09-17 15:57

【摘要】：我国是一个崩塌灾害较多的国家,崩塌灾害给人民的生命财产安全带来了巨大的损失和威胁,尤其是西南地区,西南地区山高谷深,地质构造发育,区域性大断层较多,地震灾害频发,以至于该地区崩塌灾害数量较多,并且方量巨大。2014年8月3日云南省鲁甸县发生了6.5级地震,地震造成鲁甸县火德红镇李家山村红石岩组牛栏江干流北岸发生特大崩塌,将牛栏江截断形成堰塞湖。经专家仔细调研,决定变废为宝,以堰塞坝为坝体修建红石岩水电枢纽工程。在地震和常年风化剥蚀的作用下,库区两岸边坡高陡,崩塌灾害严重,震后一年多时间内有数次崩塌发生,方量最大的达到7万多方,成为水利工程建设和运营的最大安全隐患。本文以库区岸坡崩塌为研究对象,系统分析了古崩塌、8·3地震崩塌、震后崩塌以及岸坡潜在崩塌,详细分析了库区崩塌发育特征、失稳模式,评价潜在崩塌体的稳定性,研究了枢纽区落石运动特征。论文取得成果如下:(1)研究了崩塌的发育分布规律。以时间、空间和运动特征为出发点研究了区内古崩塌、地震崩塌、震后溢洪洞进口崩塌和珍珠岩潜在崩塌的发育分布规律,发现崩塌按照时间顺序规模依次减小、右岸多于左岸等特点。(2)结合库区发生的崩塌,详细分析了崩塌破坏的失稳模式,根据崩塌的形成过程和失稳时的瞬间形态,将崩塌划分为以下类型:倾倒式、滑移式、错断式、拉裂式、鼓胀式。(3)运用非连续变形分析(DDA)法模拟8·3地震崩塌(B1),分析地震作用下崩塌失稳模式和特征,发现地震作用下崩塌与常规重力环境下的崩塌失稳模式不同,具有独特的震裂和抛射现象,并且崩塌块体运动距离远,携带能量巨大。(4)分析了影响崩塌稳定性的因素。综合分析库区地质条件,发现地形地貌、地震(爆破振动)、地质构造、水的作用、地层岩性及其组合,是主要影响因素,地震是研究区崩塌发生的最关键因素。(5)采用极限平衡法和离散元(UDEC)法分析了珍珠岩边坡潜在崩塌体ZZWY1的稳定性,考虑了天然工况和暴雨工况两种工况,发现潜在崩塌体天然态处于基本稳定状态,而暴雨状态安全系数小于1.1,稳定性差,考虑到安全储备,该潜在崩塌体应进行有效处理。(6)运用Rockfall软件分析库区岸坡崩塌落石运动规律,研究了右岸交通洞口上方和左岸古崩塌陡壁崩塌落石的运动轨迹,并且利用数值分析的结果给出相应的被动防护措施。采用路基规范法、隧道手册法、日本道路公团等方法计算了滚石对棚洞、挡土墙的冲击力。以上成果对红石岩水利枢纽工程具有实际意义。通过研究岸坡发育分布规律,得出了潜在崩塌的发育分布特点,结合野外调查划定了重点防治范围;对区域内稳定性较差、危害性较高的潜在崩塌体(ZZWY1)的稳定性进行了详细评价,认为ZZWY1稳定性差,应该进行加固或清除;研究了坝址区左右两岸滚石运动特征,给出了拦石墙的设置位置及修筑高度和棚洞的设置长度,并计算出了拦石墙和棚洞冲击力的建议值。
[Abstract]:China is a country with more collapse disasters. The collapse disasters have brought enormous losses and threats to people's lives and property security. Especially in southwest China, the mountains and valleys in southwest China are deep, the geological structure is developed, there are more regional large faults and frequent earthquake disasters, so that the number of collapse disasters in this area is large and the amount of collapse disasters is huge. An earthquake of magnitude 6.5 occurred in Ludian County, Yunnan Province, on March 3. The earthquake caused a great collapse on the North Bank of the Niulanjiang main stream of the Hongshiyan Formation in Lijiashan Village, Huodehong Town, Ludian County. The Niulanjiang River was cut off to form a barrier lake. Under the action of denudation, the slopes on both sides of the reservoir area are high and steep, and the collapse disasters are serious. Several collapses occur in more than one year after the earthquake, with the largest volume reaching more than 70,000. This paper takes the bank slope collapse in the reservoir area as the research object, systematically analyzes the ancient collapse, 8.3 earthquake collapse, post-earthquake collapse and so on. Potential collapse of bank slope is analyzed in detail. The development characteristics, instability model, stability evaluation of potential collapse are analyzed, and the characteristics of rock fall movement in key area are studied. According to the development and distribution of the entrance collapse and the potential collapse of perlite, it is found that the collapse decreases in time sequence and the right bank is more than the left bank. Type I: toppling, slipping, staggered, tensile and bulging. (3) The discontinuous deformation analysis (DDA) method is used to simulate the 8.3 earthquake collapse (B1) and analyze the collapse and instability mode and characteristics under earthquake. It is found that the collapse under earthquake is different from the collapse and instability mode under normal gravity environment, and has a unique phenomenon of seismic cracking and throwing. (4) The factors affecting the stability of collapse are analyzed. The geological conditions of the reservoir area are analyzed comprehensively. It is found that topography, earthquake (blasting vibration), geological structure, water action, stratum lithology and their combination are the main influencing factors. Earthquake is the most critical factor for the occurrence of collapse in the study area. (5) The limit equilibrium method is adopted. The stability of ZZWY 1, a potential collapse of perlite slope, is analyzed by using the discrete element method (UDEC). The natural state of the potential collapse is basically stable under both natural and rainstorm conditions, while the safety factor of the rainstorm state is less than 1.1 and the stability is poor. Considering the safety reserve, the potential collapse should be treated effectively. Rockfall software is used to analyze the movement law of bank slope collapse and rock fall in the reservoir area, and the movement track of the ancient collapse and rock fall above the right bank traffic tunnel entrance and on the left bank is studied, and the corresponding passive protection measures are given according to the results of numerical analysis. The above results are of practical significance to the Hongshiyan Hydro-junction Project. By studying the development and distribution of bank slope, the characteristics of potential collapse are obtained, and the key prevention and control areas are delineated based on field investigation. The stability of potential collapse (ZZWY1) with poor stability and high hazard in the region is improved. It is considered that the stability of ZZWY1 is poor and should be strengthened or cleared. The movement characteristics of rolling stones on both sides of the dam site are studied, the setting position of the retaining wall, the height of the building and the setting length of the shed tunnel are given, and the recommended values of the impact force of the retaining wall and the shed tunnel are calculated.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P642.2

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