岩质边坡的地震动特性及基覆型边坡的滑坡成因机理、稳定性判识、危害范围评价体系的研究

发布时间：2018-04-05 23:06

本文选题：基覆型边坡　切入点：动力特性　出处：《西南交通大学》2014年博士论文

【摘要】：地震作用下边坡的动力稳定性分析涉及到工程地质学、岩土力学、地球物理学、地震工程学等多个学科的交叉,难度较大,目前仍存在很多亟待突破的问题,而我国西部特殊的地理条件和地震构造活动决定了边坡地震稳定性问题在该地区尤为突出。目前,我国的公路、铁路、水利等基础设施建设正处于高速发展时期,这就对边坡工程的稳定性判识和滑坡的危害性评价提出了更高的要求,以致现有的理论尚不能很好地满足这一需求。因此,开展边坡地震稳定性分析研究对降低地震滑坡灾害,给山区人民创造一个良好的生存环境,保障大型岩土工程设施的安全正常运营具有重要的意义：本论文在简要回顾边坡地震稳定性问题的研究历史与现状的基础上,以汶川地震为大背景,针对现阶段存在的相关科学问题,以地震作用下边坡的动力特性为主线,以现场调查、地震台阵实测数据、振动台试验、数值分析及理论分析为手段,探明地震作用下岩质边坡的动力特性,并在此基础上,以地震中破坏最为严重的基覆型边坡(本文定义：基覆型边坡是指表面分布一定厚度或范围覆盖层的岩质边坡,而由基覆型边坡滑塌所形成的滑坡称为基覆型滑坡)为研究对象,深入剖析基覆型边坡发生滑塌的成因机制,提出一套能够考虑地震动三要素(幅值、频率、持时)影响的基覆型边坡地震稳定性分析方法和预测地震诱发基覆型滑坡危害范围的评价体系。为此,本文主要完成以下研究工作：1.借助大型振动台试验、数值模拟及现场地震台阵的监测结果,研究了坡面角度、地震烈度、地震波输入类型、坡体类型以及局部坡体形态等因素对岩质边坡动力特性的影响,在上述研究成果的基础上,利用弹性波动理论推导了能够充分考虑地震波特性(持时、频率计幅值)的双面岩质边坡地震动响应的理论解,从理论计算的角度量化的揭示了地震作用下岩质边坡的动力特性。2.基于岩质边坡动力特性的研究成果,以基覆型边坡为研究对象,概化分析模型,借助新型时间-频率-幅值分析技术,结合振动台试验研究成果和数值分析结果,从时域、时频联合域两个方面系统的开展了地震作用下基覆型边坡的变形特征和滑塌成因机制的研究。3.随着对边坡动力稳定性问题研究的深入,已普遍认识到应用拟静力法进行边坡地震稳定性评价所存在的不足,边坡地震稳定性的时频分析方法已成为边坡工程抗震设计发展的趋势。本文基于弹性波动理论,概化地质分析模型,利用Hilbert-Huang变换,借助地震作用下基覆型边坡的变形特征和滑塌成因机制的研究成果,提出了基覆型边坡地震稳定性的时频分析方法,并且通过振动台试验和数值分析结果对其合理性进行了验证。4.长期以来,滑坡危害范围的预测模型中仅仅考虑了滑坡体积(V)、滑坡的最大垂直滑动距离(H)两个影响因素。然而,大量的研究成果表明,峰值地震动加速度、山体坡面的坡度等因素与滑坡分布、规模具有较好的相关性。因此,本文基于汶川地震滑坡灾害的调查结果,重点整理、分析了破坏最为严重的基覆型滑坡的灾害情况,利用地震动峰值加速度的衰减模型,建立了能够考虑山高HL、坡度θ、地震动峰值PGA以及滑塌体积V等因素影响的汶川地震诱发基覆型滑坡灾害危害范围的预测模型。
[Abstract]:The analysis relates to the engineering geology of slope dynamic stability under earthquake, rock and soil mechanics, geophysics, cross disciplines, such as difficulty in earthquake engineering, there are still many problems to be a breakthrough, while China's western special geographical conditions and seismic tectonic activity determines that the problem is particularly prominent in the seismic stability of slope area. At present, China's highway, railway, water conservancy and other infrastructure construction is in a period of rapid development, the stability of slope in the identification and landslide hazard evaluation put forward higher requirements, so that the existing theory cannot satisfy this demand. Therefore, to carry out research on reducing seismic landslide hazard analysis of slope seismic stability, to create a good living environment for the people in the mountainous areas, has an important significance to ensure the normal operation and safety of geotechnical engineering facilities: Based on a brief review of research history and status quo of slope seismic stability on the Wenchuan earthquake as the background, according to the relevant scientific problems, the dynamic characteristic of the slope under earthquake as the main line, to the scene investigation, seismic array data, shaking table test, numerical analysis and theoretical analysis it means, dynamic characteristics of rock slope under earthquake, and on this basis, the earthquake damage is the most serious type of bedrock slope (defined in this paper: base cover type refers to the slope rock slope, the surface distribution of a certain thickness range or cover layer and the base cover type slope collapse formed the landslide is called overburden landslide) as the research object, in-depth analysis of the formation mechanism of landslide occurrence overburden slope, put forward a set of ground motion can be considered three factors (amplitude, frequency, duration) of seismic slope stability influence of the base cover type Analysis and prediction of earthquake induced landslide hazards based cover range evaluation system. Therefore, this paper mainly completed the following research work: 1. through shaking table test, numerical simulation and field seismic array monitoring results of slope angle, seismic intensity, seismic wave input type, the influence of slope type and local slope the body shape and other factors on the dynamic characteristics of rock slope, based on the above results, using the theory of elastic wave is able to fully consider the characteristics of seismic waves (duration, frequency amplitude) double slope seismic response theory, from the theoretical calculation of angle quantization reveals that under the action of earthquake rock slope dynamic characteristics research of.2. dynamical properties of rock slope based on the base cover slope as the research object, generalized analysis model, with the help of new time - frequency - amplitude analysis technology, With shaking table test results and numerical analysis results, from the time domain, time-frequency domain two aspects of the system to carry out the deformation characteristics of bedrock slope under earthquake and landslide formation mechanism of.3. with the research of dynamic stability of slope depth, is generally recognized that insufficient application of pseudo static method exists to evaluate the seismic stability of slope, the time-frequency analysis method of slope seismic stability of slope engineering seismic design has become a development trend. This paper based on the elastic wave theory, geological analysis model, using Hilbert-Huang transform, research by means of the deformation characteristics of bedrock slope under earthquake and landslide formation mechanism, put forward when the frequency stability of the base cover type slope seismic analysis method, and through the shaking table test and numerical analysis results verified the rationality of.4. for a long time, slip The prediction model of slope hazard scope only considers the landslide volume (V), the maximum vertical sliding distance of landslide (H) two factors. However, a large number of research results show that the peak ground acceleration, slope factor and landslide distribution of mountain slope, there is good correlation scale. Therefore, the investigation results in this paper the landslide in Wenchuan earthquake, based on the analysis of the key arrangement, the disaster situation serious landslide and bedrock for destruction, the attenuation model of seismic peak acceleration using the established to consider the mountain slope HL, theta, prediction model range of hazards induced by Wenchuan earthquake landslide disasters and bedrock peak ground collapse and PGA the volume of V and other factors.

【学位授予单位】：西南交通大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：P642.22;TU435

【引证文献】