【作者】 刘红帅；

【导师】 薄景山；

【作者基本信息】 中国地震局工程力学研究所 ， 岩土工程， 2006， 博士

【摘要】 地震作用下边坡的稳定性问题是当前岩土地震工程和地震工程学研究的热点问题之一。研究表明,全球地震带的分布和滑坡带的分布具有惊人的一致性,这一现象充分反映了地震对岩土边坡失稳的触发作用。由于岩土材料的组成和本构关系的复杂性,加之地震动这一随机荷载的特殊性,使得地震作用下边坡稳定性研究内容变得十分复杂。本文针对岩质边坡在地震动随机荷载作用下的稳定性问题开展了一些初步的研究工作。本论文主要做了以下研究工作:1.回顾了岩土边坡地震稳定性分析研究中的若干重要问题的研究进展,包括边坡岩土体地震反应分析方法、边坡岩土体的动力特性和强度准则及参数测试、边坡地震失稳机理与失稳位置、边坡地震稳定性评价方法、边坡地震稳定性评价指标与安全标准、边坡地震动输入、边坡地震稳定性评价指标的计算精度,作了简要评述,并指出了需要解决的一些问题。2.针对岩质边坡存在明显的软弱带的特点,给出了有限元计算过程中不同软弱带的处理方法,结合工程中常用的极限平衡法,给出了岩质边坡稳定性的有限元分析方法,将其应用于某一岩质边坡,该方法为岩质边坡地震稳定性分析提供初始静应力场和安全系数。在此基础上,研究了材料参数对岩质边坡安全系数的影响。3.真实反映地震动传播特性的分析方法是准确描述岩体地震反应的基础。发展了一种能够考虑岩体动力特性-弹粘塑性的显式波动有限元分析方法,阐述了真实描述岩体地震动传播的弹粘塑性显式波动有限元的计算原理及实施细节,包括岩体弹粘塑性的本构关系、时域显式位移递推公式和两侧边界不等高的透射边界实施思路,编制了计算程序。以简单岩质边坡为例,分析了一位移脉冲和真实地震波输入下的岩质边坡的地震反应,初步定性地验证了程序的可靠性。4.给出了岩质边坡动力安全系数时程的计算方法,在此基础上,引入可靠度概念,提出了岩质边坡动力安全系数的概念,给出相应的计算方法,将其应用于某岩质边坡,并与拟静力法的结果进行了比较。5.研究了输入地震动峰值及频谱特性对岩质边坡稳定性的影响,给出了不同输入地震动峰值时拟静力安全系数与边坡动力安全系数之间的关系式及两者之间的修正系数,同时给出了输入地震动峰值与边坡动力安全系数之间的关系,为大型边坡的快速评估提供了一种可行的思路。此外,研究了竖向地震动输入对岩质边坡稳定性的影响。6.国道108线石棉大渡河雅安岸引道高陡边坡的稳定直接关系到国道更多还原

【Abstract】 Seismic stability of slope is one of hot problems in geotechnical seismicengineering and earthquake engineering field. Studies show that there areegregious coherence between the distribution of global earthquake belts andlandslide belts, which sufficiently reflects the effects of earthquake inducing onslope stability losing. That complexity of the composition of geological materialsconstitutive models and speciality of earthquake ground motion with strongrandomicity make slope seismic stability difficult. Some primary studies, aimedat seismic stability of rock slope under earthquake ground motion are carried on.The main studies are as follows:1. The state-of-the-art advancement of several important problems onseismic stability analysis of rock-soil slopes is reviewed, including analysismethod of seismic response, dynamic properties, strength criteria, parametertesting, failure mechanism& failure location, seismic stability evaluation methods,seismic stability evaluation index &safety standard, earthquake input andcomputation accuracy of seismic stability evaluation index, and concise remarksare made. Then some study problems, which need to be done in future, aresuggested.2. Considering obvious weak slip zone occurring within rock slope, thedifferent slip zone analysis methods during the calculation of finite element arebrought forward and the method combining the finite element method with limitequilibrium method used in engineering is presented. The method proposedpresent initial static stress field and safety factor for seismic stability analysis ofrock slope. The method is used to calculate one rock slope. On the basis of this,the effects of material parameters on safety factor of rock slope are studied.3. The analysis method truly reflecting characters of earthquake groundmotion transmitting is the basis of concisely describing seismic response ofrock-mass. A new method, explicit wave motion fem, with considering theElastic-viscoplastic dynamic properties of rock-mass, is proposed, and itscomputation theories and details, including constitute model ofelastic-viscoplastic of rock, step-by-step formula of displacement, execution ofmulti-transform formula with both different height, are expounded, then programare coded. As a case of simple rock slope, its seismic responses under onedisplacement pulse and true earthquake record input are analyzed, and thecorrectness of program is verified.4. The calculation method of dynamic safety factor time history of rockslope is present, and based on it, the concept of dynamic safety factor of rockslope is proposed introducing the idea of reliability theory. The computationmethod of dynamic safety factor of rock slope is proposed. It is used to calculateone rock slope, compared with that of pseudo-static method.5. The effects of input ground motion peak and frequency content onstability of rock slope are studied. Then, the relations of pseudo-static safetyfactor and dynamic safety factor of rock slope, input ground motion peak anddynamic safety factor of rock slope are given, which provides a feasible methodfor predicting seismic stability of important rock slopes. In addition the effects ofvertical input ground motion on stability of rock slope are studied.6. The stability of high and steep slope along leading road along DaduheRiver’s Ya’an bank Country Road No. 108 directly decides natural running of theroad and Daduhe bridge in Shimian. Based on comprehensively analyzing theregion earthquake seismic activity, earthquake geological structures, potentialearthquake source in the slope region are acquired, and acceleration peak andtarget spectra of the slope site, whose probability of exceedance is 10% in 50years, are computed. Based on these, 3 pieces of man made earthquake waves aregenerated by triangle progression. As the inputs of generated waves, the seismicstability of high and steep slope along, lying at leading road along DaduheRiver’s Ya’an bank Country Road No. 108 is computed, using the method ofdynamic safety factor of rock slope.更多还原