【作者】 崔凯；

【导师】 韩文峰； 谌文武；

【作者基本信息】 兰州大学 ， 地质工程， 2009， 博士

【副题名】以交河故城台地边坡为例

【摘要】 边坡变形破坏是各种地质灾害中分布最广、发生最频繁、对人类危害最大的灾害类形之一。随着国民经济的发展，工程活动的数量、速度及规模越来越大，所面临的各类边坡失稳问题也越来越多，其研究对象现已不只局限于大型的岩质边坡的失稳问题，土质边坡的失稳问题也引起越来越多学者和工程师的广泛关注，尤其是高陡土质边坡的变形破坏的问题已经成为该领域的研究焦点和难点。高陡土质边坡的变形破坏是内因和外因共同作用控制的复杂过程，其中外因主要有降雨、蒸发、地震以及人类工程活动等，各因素对边坡的影响程度决定着边坡的演化机制与破坏模式。正确认知诱发边坡变形破坏的因素，是评价其稳定性、预测其演化趋势、指导其岩土体物理力学参数选取、预防和整治边坡的关键。目前许多学者对影响土质边坡的变形破坏的外因(诱发因素)的研究多集中于水库、地震、人类工程活动、降雨以及蒸发等方面；而对于干旱多风地区的风这一土质边坡变形破坏的主要诱发因素尚未做过深入的研究。鉴于上述认识，选择干旱多风的吐鲁番交河故城台地的多元层状陡立边坡为典型实例，基于风蚀而诱发的边坡变形破坏现象，提出多元层状土质边坡差异性风蚀效应的概念，并运用野外调查、取样、颗粒分析实验、微结构分析、风洞实验、数值模拟等手段对多元层状陡立土质边坡差异性风蚀效应进行了系统的研究。主要研究内容如下：(1)研究区地质环境特征。在总结前人研究成果和大量的现场调研的基础上，对吐鲁番交河故城台地的多元层状陡立边坡的地质环境进行了系统的分析，一方面，在对其工程地质环境条件展开全面研究的基础上，详细阐述地形地貌和地层岩性这两个对多元层状陡立边坡差异性风蚀效应影响较大的因素的特征；另一方面，在系统分析了吐鲁番的气候特征的前提下，重点分析了多元层状陡立边坡差异风蚀性效应的主要诱发因素-风的特征。(2)边坡土体的工程特性实验。在对多元层状陡立边坡差异性风蚀效应定性认识的前提下，选择了典型的研究区段并在其剖面上进行了原状样品的采取。对所采原状样品进行了全面而系统的物理、力学实验，一方面，充分证明了组成边坡土体物理、力学性质的差异性，尤其是在以吐鲁番当地常见风速的挟沙风的风洞实验所表现的抗风蚀能力的差异性；另一方面，为边坡的稳定性评价给出基本的物理、力学参数。(3)边坡差异性风蚀效应的形成条件与影响因素。在对吐鲁番交河故城台地多元层状陡立边坡的地质环境的分析和大量现场定性认识的基础上，提出了多元层状陡立边坡差异性风蚀效应的概念，并归纳出其形成的必备条件；而后结合室内实验的结果，从宏观和微观两个角度，分析了风的类型、挟沙风的风速、土的颗粒组成、微观结构特征参数等因素的影响。(4)差异性风蚀效应作用下多元层状陡立土质边坡的演化模式与机理分析。归纳和总结出由差异性风蚀效应而导致交河故城台地多元层状陡立边坡的三种演化模式，运用地质历史成因法对三种演化模式的机理进行了定性分析，而后利用有限差分数值方法软件对其机理进行了定量分析；以定性分析和定量评价相结合的方法，全面系统的分析了三种演化模式下边坡失稳的成因、过程和演化机理。(5)差异性风蚀效应作用下多元层状陡立土质边坡的稳定性评价。结合对吐鲁番交河故城台地多元层状陡立边坡的地质环境特征的详细分析，给出边坡遭受差异性风蚀作用后可能面临的正常、集中式降雨作用、地震作用以及降雨和地震耦合4种工况，并以工程地质力学的定性分析方法和有限元数值模拟的定量分析方法相结合对由差异性风蚀效应引起多元层状陡立边坡的三种变形破坏模式进行稳定性评价。更多还原

【Abstract】 The deformation and destroy of slopes is one of the disasters that is the most wide,frequent and serious one in all disasters.With the national economy developed,thequantity of the engineering activities,speed and scale are becoming more and greater.The problems of the slope instability are more and more.The object of study is notonly the instability of broad batholithn slope.The problems of the slope instabilityhave been drawn much attention by more and more engineers and scholars.Especially,the problem of the deformation and destroy of high steep soil slope has been the focusand difficulty in the filed.The deformation and destroy of high steep soil slope is a complex process whichis controlled by the internal and external causes.The external cause includes rainfall,evaporation,earthquake and human’s engineering activity,and ect.All the causes thatinfluence the slope decide the evolvement system and destroy pattern.So it is he key toevaluate the stability,predict the evolvement,direct the parameter choice of rockphysical mechanics and protect and renovate the slope to cognate the factors ofinducing the deformation and destroy of high steep soil slope.At present,manyscholars concentrate on the study of reservoir,earthquake,human’s engineeringactivity,rainfall and evaporation and ect,which external causes influence thedeformation and destroy of high steep soil slope.However,it doesn’t study deeply tothe main inducing factors of the deformation and destroy of high steep soil slope of thedry and windy area.Base on the recognition of above point of view,the typical case is the multivariatelayered steep soil slope in the Jiaohe ancient city mesa in Turpan,which is dry andwindy.Base on the phenomenon of wind erosion of the deformation and destroy ofhigh steep soil slope,the concept of the multivariate layered steep soil slope by winderosion is mentioned.And it is the systematic study to the different wind erosion of themulti-element layered soil slope by the methods of the field survey,sampling,the grainsize analysis experiment,micro-structural analysis and wind tunnel test,data imitation. The main study can divide into following sections:(1)Study the geological environment character.Under the base of many scenesurvey and summary data,there is a systematic analysis to the geological environmentof the multivariate layered steep soil slope in the Jiaohe ancient city mesa in Turpan.On the one hand,on the base of the whole study to the engineering geologicalenvironment,it detailed the characters,which are influenced by the different winderosion of the multi-element layered soil slope.On the other hand,on the premise ofanalysis the character of Turpan’s climate,it emphases on the analysis the maininducing factors,the character of wind,in the different wind erosion of themulti-element layered soil slope.(2)The engineering’s characters of the soil in the slope.On the premise ofqualitative recognition of the different wind erosion of the multi-element layered soilslope,choosing the typical studied section and adopting the original samples,in whichhave a whole and systematical physical and mechanics experiments.On the one side,enough proved the differences of physical and mechanic nature.Especially,thedifferences of resisting the wind erosion,which is performed by the wind tunnel test inthe laboratory of the sediment-carrying wind speed in Turpan area.On the other side,the basic index of physical and mechanics for the evaluation of the stability to the soilslope.(3)The conditions and effected factors of the different wind erosion effect ofthe soil slope.On the base of analysis for the geological environment and muchpresent qualitative recognition in the Jiaohe ancient city mesa in Turpan,it mentionsthe concept of the different wind erosion of the multi-element layered soil slope andconcludes the necessary forming conditions;And then combining the result of insideexperiments,from micro and macro view,analyzing the special effects of the type ofwind,the sediment-carrying wind speed,soil grain composition,micro-structure index.(4)The effects of the different wind erosion to the evolved pattern andmechanistic analysis.Concluding and summarizing three evolved patterns of theJiaohe ancient city mesa in Turpan because of the different wind erosion effect of thesoil slope.Adopting the geological history causes,to qualitative analyze the mechanism of the three patterns.And then have a quantitative analyze of themechanism by finite difference method.Combining the qualitative analysis andquantitative analysis,it analyzes the stability of forming,processing and evolvingunder the three evolved patterns.(5)The evaluation of stability under the different wind erosion effect for themulti-element layered soil slope.Combining the detailed analysis of geologicalenvironment for the multi-element layered soil slope in the Jiaohe ancient city mesa inTurpan,the four effected situations of centralized rainfall,earthquake and rainfall andearthquake are faced by the different wind erosion effect.Combining the ways of thequalitative analysis and the qualitative analysis of finite difference method ofengineering geomechanics,it evaluates steadily the three patterns of the multi-elementlayered soil slope because of the different wind erosion effect.更多还原