IMHE OpenIR  > 山地灾害与地表过程重点实验室
地震触发岩质滑坡破坏模式与危险性预测
Alternative TitleRock Landslide Failure Mode and Risk Forecast Induced by Earthquake
Language中文
江兴元
Thesis Advisor崔鹏
2016
Degree Grantor中国科学院大学
Place of Conferral北京
Degree Name博士
Degree Discipline岩土工程
Keyword岩质滑坡 坡体结构 地质强度指标 破坏模式 永久位移预测模型
Other Abstract

岩质滑坡问题一直是岩土工程和山地灾害领域研究的热点之一,特别是我国西部地区特殊的地形地貌和构造活动造成了本区域斜坡失稳问题突出。随着我国西部经济建设的快速发展,西部山区的大型水利水电、铁路和公路交通、市政等工程建设正处于高速发展阶段,对我国西部地震高发山区斜坡工程的稳定性判识、失稳模式与触发机制探讨、滑坡的危险性预测等关键问题提出了更高的要求。论文以地震触发岩质滑坡为研究对象,开展岩质斜坡坡体结构特征和稳定性问题的研究,以西南地区2008年至今多次地震触发的岩质滑坡为研究实例,结合文献资料收集和野外调查方法,分析了岩质滑坡的地质环境条件和斜坡岩体结构特征,总结了岩质斜坡坡体结构类型、破坏模式,并通过对斜坡岩体地质强度指标特征的定量化描述,建立了基于岩体结构特征的滑坡破坏模式分区。以单体斜坡和区域斜坡为研究对象,以斜坡稳定性安全系数和永久位移为考察指标,建立了基于斜坡岩体非线性强度准则(Hoek-Brown强度准则)的地震触发岩质斜坡稳定性快速评价方法和基于Newmark滑块理论的区域斜坡永久位移预测模型,并通过考察实例的应用,验证了模型的有效应。论文的主要研究成果和结论具体表现如下:(1)基于坡体结构特征的斜坡分类与分区在坡体结构特征的相关研究的基础上,对坡体结构类型及其破坏模式进行了归纳和概括,将坡体结构类型划分为5大类:类均质坡体结构、层状控制型坡体结构、节理控制型坡体结构、软硬交替型坡体结构、软弱破碎带控制型坡体结构。并在此基础上,借助野外调查、三维激光扫描和赤平面投影分析方法,开展地震触发典型岩质滑坡坡体结构特征分析,并从定量化的角度,构建了基于坡体地质强度指标参数的斜坡分区。(2)基于HB强度准则岩质斜坡稳定性图表分析方法基于斜坡岩体非线性强度准则和极限平衡理论,采用拟静力分析方法,构建考虑地震荷载条件的岩质斜坡稳定性图表分析方法。首先借助数值计算方法分别计算斜坡坡度为30°条件,静态和拟静态条件下斜坡安全系数;其次,改变地震荷载条件和斜坡坡度参数,基于计算结果构建地震水平加速度权重因子和坡度权重因子,通过回归分析给出其计算表达式,结合静态条件下斜坡安全系数图表,最终构建岩质斜坡稳定性快速评价方法。最后,将本文提出的计算方法与数值计算结果进行了对比,70.63%的计算结果误差能够保持在±10%范围以内,并通过计算结果分析发现误差值较大的结果主要分布在斜坡地质强度指标GSI和水平地震加速度系数较大的条件下,且这类斜坡安全系数一般小于1。(3)岩质斜坡永久位移预测方法在回顾9类基于Newmark滑块理论提出的地震斜坡永久位移预测模型的基础上,基于汶川地震及之后发生在中国西南地区地震震级Ms>6.0强震台站记录数据,分别计算和统计强震台站峰值加速度(PGA)、距震中距离(RE)、距离断层距离(RF)、Arias强度(Ia)等强度参数值。斜坡永久位移计算过程中,给定临界加速度序列:0.05g、0.1g、0.15g、0.2g、0.25g、0.3g、0.4g、0.5g和0.6g,对844条强震记录,分别计算9种临界加速度下的Newmark永久位移。并提出了基于临界加速度比(ac/amax)、地震震级(Ms)、Arias强度参数(Ia)和多元参数回归的5种永久位移计算模型,并通过现场实测数据与模型计算结果对比,验证了模型的有效性,结果表明,基于临界加速度比计算模型5、Arias强度参数模型10和“场-源”特征参数的回归模型,通过案例分析发现计算结果与真实值较为接近。模型5和10计算模型基于大量强震台站基础数据,参数计算过程稍复杂,耗时长,但是计算精确度较好;而模型13参数较易获取,计算过程简单,计算结果准确性上稍不足。本文提出的模型可以用于我国西南地区地震滑坡的危险性评价和灾势评估,为边坡稳定性快速识别和抗震加固设计工程应用提供了定量的参考。

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Rock slope problem has always been one of the hot spots of geotechnical engineering and geo-hazard in mountain area, especially in southwest China for its special geographical conditions and seismic tectonic activities, which brought the seismic rock slope stability problems to the core. In recent years, with the continuous development of national west economic construction, and the rapid growing emergences of large scale engineering constructions such as hydraulic and hydroelectricity, railway and highway traffic and public work projects, the rock slope has received more and more attention for its stability judgments, failure mode and triggering mechanism, risk prediction in earthquake-prone mountain area.This thesis is focused on the characteristics analysis of slope structure and stability problem of rock slope under seismic effect and take the rock landslides caused by 2008 Sichuan wenchuan earthquake and the subsequent earthquake events as cases study. Combined with the literature data collection, geological data and field survey methods, the geological environment conditions and slope structure conditions are analyzed. The types of slope structure and failure modes of earthquake induced rock landslides are summarized, and based on this basis, the quantitative description method of geological structure index for rock slopes are developed, the rock slope failure mode zones are established. The rock slope stability evaluation method, which based on the non-linear Hoek-Brown rock mass failure criterion and Newmark rigid block theory, based on the inspection index of factor of safety and permanent displacement models are developed for single rock slope and regional slopes, respectively. The effect of the model is verified by the application of the cases study. The main results and conclusions of this thesis are as follows:(1) Rock slope classification and zoning based on slope strcture characterics. In reference to the related researches of slope structure, the slope strcture types and failure modes of rock slope are summarized and conclude. The slope strcture of the rock slope can be divided into six categories: approximate homogeneous slope strcture, layered slope strcture, joint controlled slope strcture, soft- hard alternate slope structure and weak zone controlled slope structure. Based on this division, the typical rock landslides were analyzed for its slope structure index from the quantitative point of view using the field investigation, three dimensional laser scanning and plane projection analysis method.(2) This paper demonstrates the use of a new form of a chart-based slope stability method that satisfies the non-linear Hoek-Brown (HB) criterion. The limit equivalent method is used to assess the stability of rock slopes subjected to seismic inertial force. First, stability charts for calculating the factors of safety (FoS) with a slope angle of β=30° in static and pseudo-static states were proposed by using Slide 6.0 software. Next, scaling factors of the horizontal seismic acceleration coefficient (fKh) and slope angle (fβ) were established to illustrate the influence of the horizontal seismic load and slope angle on the stability of rock slopes, respectively. Using regression analyses of fKh and fβ, a fast calculation model was proposed to solve the slope safety factors based on the stability charts. Finally, the stability charts analysis method (SCAM) was verified against the numerical solutions; the results showed that 70.63% of the data had discrepancies of less than ±10%, and the data with discrepancies greater than ±10% were associated with high values of geological strength index (GSI) and horizontal seismic acceleration coefficient (Kh). The proposed model calculating the FoS of rock slopes is simple and straightforward to use for seismic rock slope design and stability evaluation.(3) Nine kind of permanent displacement models were reviewed and summarized based on the Newmark sliding block theory; based on the strong earthquake station records with magnitude of Ms>6.0 in from Southwest China region, the Peak ground accelerations (PGA), distance from epicenter (RE), distance from the surface rapture zone (RF), earthquake intensity parameters such as Arisa intensity (Ia) et al. are calculated and counted. The permanent Newmark displacement was calculated under the condition of nine critical acceleration set values :0.05g、0.1g、0.15g、0.2g、0.25g、0.3g、0.4g、0.5ga nd 0.6g for 844 records from strong earthquake stations. Five regression models in terms of the critical acceleration ratio-(ac/amax), the earthquake magnitude (Ms) and Arias intensity et al. are established. The validation is tested by the displacement conversion from the in situ data and the model calculations. The result showed that, the calculation results from models 5, 10 and 13 are in agreement with the measured values. Models 5 and 10 are based on the large quantity of strong earthquake station data, which need complex calculating process and take a long time to get the result, but these two models have a high prediction precision. In model 13, all of the parameters are easy to get with simple calculations, but the prediction precision was a little worse. The proposed models can be applied to earthquake-induced landslide risk assessment and changing trends evaluation, and to provide references for the rapid identification of slope stability and applications of seismic slope reinforce engineering design. 

Document Type学位论文
Identifierhttp://ir.imde.ac.cn/handle/131551/18978
Collection山地灾害与地表过程重点实验室
Affiliation中国科学院成都山地灾害与环境研究所
Recommended Citation
GB/T 7714
江兴元. 地震触发岩质滑坡破坏模式与危险性预测[D]. 北京. 中国科学院大学,2016.
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