【中文摘要】降雨进渗时边坡的稳定性题目不仅牵涉到饱和-非饱和的渗流规律,而且涉及含水率变化对非饱和土的强度参数的影响作用。本文针对不同的土体性质,分析了不同降雨条件对土坡渗流及稳定的影响,运用饱和-非饱和渗流理论及降雨进渗理论,分析了渗流场的变化过程,根据计算出来的瞬态渗流场利用非饱和土抗剪强度理论,对土坡的瞬态稳定性进行了分析。研究的主要内容有:1先容了降雨条件下的饱和-非饱和渗流基本理论,先容了非饱和渗流的控制方程,给出了降雨条件下的边界条件。2基于Galerkin加权余量法得出了饱和.非饱和渗流计算有限元列式。针对不同的土体性质,利用简单的土质边坡有限元模型运用SEEP/W渗流计算程序计算在给定降雨条件下的孔隙水压力的分布,探讨降雨强度、降雨持时、雨型、土壤渗透系数以及边坡坡度等参数的变化对渗流场的影响。3先容了饱和-非饱和渗流条件下边坡稳定分析理论。运用GEO-SLOPE(SLOPE/W模块)软件,将降雨进渗作为土坡稳定分析的重要因素,将渗流场的孔隙水压力引进基于非饱和土抗剪强度理论的抗滑稳定计算中。定量的得出在各降雨因素及边坡坡度对非饱和土坡稳定性影响的程度;探讨各参数变化对边坡安全系数的影响,并对边坡的稳定性进行了评价。分析结果表明:在甘肃大部分地区边坡坡度比降雨对边坡的稳定性影响更大;在甘肃大部分地区在可能发生的降雨条件下,坡角大于65°的边坡就要考虑对边坡进行支护。');
【Abstract】 The stability problem of slopes under rainfall involves not only the saturated-unsaturated seepage law,but also the effect of water contect changes on the intensive parameter of unsaturated soil.For different the soil characteristics,the Seepage and stability of slope under rainfall is analyzed.Based on the saturated-unsaturated seepage theory and rainfall infiltration theory,the change of seepage fields is analyzed.On the basis of calculated transient seepage field and the shear strength theory of unsaturated soil,the transient stability of slope is analyzed.The main conclusions are as follows:1 The saturated-unsaturated seepage theory under rainfall condition and the governing equation of unsaturated seepage are introduced.The boundary conditions are attained.2 The FEM format of saturated-unsaturated seepage differential equation is drawed based on Galerkin\'s method of weighted residual.For the different property soil,pore water pressure field under different rainfall conditions are calculated by adopting FEM model of *** earth slope using SEEP/W flow calculation procedures.The impacts of seepage field under the varies with rainfall intensity,duration of rainfall,rain type,soil permeability coefficients and slope angle are discussed.3 The basal theory of saturated-unsaturated slopes\' stability is introduced. Regarding rainfall seeping as an important factor of soil slope stability analysis,the distribution of pore water pressure of seepage field is calculated and introduced into the formula of safety factor useing GEO-SLOPE(SLOPE/W module)sofeware.The impacts of non-saturated slope stability are quantitatively drawed under the influence of rainfall and slope gradient;the varies of parameters are discussed on the impact of slope safety and the stability of the slope is evaluated.The results show that in most parts of Gansu slope gradient have a greater impact on the stability of slope than rainfall;under the possible rainfall conditions,the slopes of more than 65~0 slope gradient are considered supporting.

地震作用下的滑坡稳定性分析
Dynamic and Stability of Landslide under Earthquake Loading
论文作者
论文导师 姚令侃,论文学位 硕士,论文专业 道路与铁道工程
论文单位 西南交通大学,点击次数 32,论文页数 142页File Size9414K
2006-11-01论文网 http://www.lw23.com/lunwen_785799717/
earthquake; landslide; stability coefficient; finite element method; GPS inspection
地震滑坡因其巨大的致灾力而广泛引起人们的关注，仅20世纪，地震滑坡已经造成了数万人丧生和几十亿美元的损失。地震滑坡一直是困扰土木工程界的一个世界性技术难题，其发生和发展过程与很多因素有关，至今尚未得到根本解决。本文在广泛吸取国内外地震作用下滑坡稳定分析研究经验的基础上，通过地震滑坡分区，分析了地震滑坡与地震震级、震中距、震源深度的关系，并研究了地震对滑坡的影响机理。在对西攀高速公路沿线滑坡进行全面调查的基础上，运用地震危险分析，确定了地震烈度的分区，给出了滑坡灾势评估。对全线滑坡工点进行调查，找出与工程密切相关的15处滑坡，确定Ⅷ度地震区以德昌滑坡为典型分析对象，Ⅶ度地震区以米易滑坡为典型分析对象。通过定量分析地震力和滑坡稳定性之间的关系，对地震作用下滑坡稳定性分析进行研究。以地震加速度作为反映地震荷载的主要因素，以德昌、米易滑坡为例，基于有限元理论，开展了地震作用下滑坡的动力学分析，运用GEO—SLOPE软件模拟地震对滑坡的影响机制，用QUAKE／W模块分析软件进行求解，研究滑坡稳定性的变化规律。主要内容包括：运用GEO—SLOPE软件，获得了米易电力公司滑坡、德昌滑坡在不同地震加速度作用下的安全系数随时程的变化曲线；在此基础上对两个滑坡在自然状态和采取排水措施两种情况下的计算结果进行了比较，讨论并分析了地震对滑坡稳定性的影响，从而对工程设计措施提出技术建议。这些工作可为滑坡的抗震设计提供理论依据和指导。通过对地震区米易、德昌滑坡的两年GPS外部变形监测，提出了地震区滑坡稳定性监测的原则和方法。
Earthquake-induced landslide has got people"s attention because of its huge disaster strength. Only in 20th century, the earthquake-induced landslide had resulted tens of thousands lives loss and several thousands US dollars losses. Earthquake-induced landslide has always been a worldwide difficult problem in the civil engineering, which is related with many factors and haven"t been solved its occurrence and development.Based on the previous study on the stability of landslide induced by the earthquake, through zoning the earthquake-induced landslide, in this paper the author studies the relation between the earthquake-induced landslide and seismic parameter, the influence mechanism and factors of earthquake to landslide.With the widespread investigation to landslide along the highway route from Xichang to Panzhihua, through the analysis of the risk of earthquake along the route, the author made out the evaluation on the earthquake-induced landslide along the highway and gave the zonal spot of earthquake intensity. Through the investigation to landslides along the route, the author chose 15 landslides which are related closely with engineering, the author chose Dechang landslide as the typical object of Ⅷ dgree and Miyi landslide as Ⅶ degree.Through the studying on landslide stability induced by earthquake and qualitativly analyzing the relation between the landslide stability and seismic force, the author found the destructive phenomenon of earthquake was not appearing or developing as constant force, but was related closely to earthquake acceleration. The aim of this paper consists in the method to analyze the landslide stability induced by earthquake and to find out the effective measure to prevent landslide"s occurence.Based on the finite element theory, through using GEO-SLOPE software to modify the influence mechanism of earthquake to landslide and the rule of landslide stability, the author built the dynamics analysis model of landslide and took Dechang landslide as example, used QUAKE/W module software to

降雨入渗对土坝渗流及坝坡稳定性影响的研究
Research of the Earth Dams" Seepage Field and Slope Stability Based on the Rain Infiltration
论文作者
论文导师 严文群,论文学位 硕士,论文专业 水利水电工程
论文单位 扬州大学,点击次数 29,论文页数 95页File Size8967K
2006-05-01论文网 http://www.lw23.com/lunwen_548594987/
rain infiltration; FEM; saturated-unsaturated seepage; pore water pressure; hydraulic conductivity; stability analysis of dams" slope
降雨入渗直接影响着土坝中的孔隙水压力分布和渗流场分布,它是土坝失稳的主要诱发因素,很多土坝滑坡都与降雨有着密切的关系。本文利用饱和-非饱和渗流基本理论和坝坡稳定分析理论,分析研究了不同降雨条件以及不同材料特性对土坝渗流场和坝坡稳定性的影响。其内容主要包括: 1、基本理论:阐述了饱和、非饱和渗流问题的基本理论,从渗流的物理方程出发推导出多孔介质饱和、非饱和渗流的基本微分方程,并建立其定解条件; 2、对降雨入渗条件下非饱和渗流进行分析研究,推导了考虑降雨入渗的非饱和渗流微分方程的有限元格式; 3、运用GEO-SLOPE(SEEP/W模块)软件,分析在降雨条件下各种参数的变化对非饱和坝坡渗流场的影响,主要包括: (1)不同降雨强度、降雨类型以及上游水位变化等的组合研究; (2)不同介质的性质,如土水特性曲线、饱和渗透系数、介质的初始状态等的影响; 4、阐述了饱和-非饱和渗流条件下边坡稳定分析理论,运用GEO--SLOPE(SLOPE/W模块)软件,分析了不同条件下,降雨入渗对坝坡稳定性的影响。本文初步分析探讨了降雨入渗对土坝渗流场以及坝坡稳定性的影响,为在雨季坝坡失稳的预报和坝坡的设计提供了科学的依据,具有一定的工程意义。
The rain infiltration directly influences the earth dams" distribution of pore water pressure and seepage field and it’s a main revulsion factor of stability . A great many landslides are correlative to rainfalls. The paper analyzes and studies the changes of seepage field and dams" slope stability in various soil slopes under the condition of rain infiltration which is studied based on the saturated-unsaturated seepage theory and slope stability theory. The following is include: 1.Fundamentals: Explaining the fundamentals of saturated-unsaturated seepage. Deducing the basic differential equation of saturated-unsaturated seepage in porous medium from fundamental physical equations and theorizing different initial and boundary conditions. 2. Analysis and study on the unsaturated seepage under the condition of rain infiltration, and to deduce the FEM format of unsaturated seepage differential equation. 3.The Study on the parameters that affect the seepage field of unsaturated slopes based on the software of GEO-SLOPE OFFICE(SEEP/W module), mainly including: (1) The combination of different rainfall intensity, type and the changes of upriver water level; (2) The influence of different medium, e.g. the soil-water characteristic curve, the coefficient of saturated hydraulic conductivity and the initial state of medium; 4. Explaining the basal theory of saturated-unsaturated slopes’stability and analyzing the influence of rain infiltration under different conditions based on the software of GEO-SLOPE OFFICE(SLOPE/W module) . In the paper, the influence of rain infiltration on the slope stability is discussed,which is very helpful for forecasting dams" slope stability in raining seasons and designing unsaturated slopes.

降雨条件下非饱和土坡非稳定渗流的数值模拟与土坡稳定分析
Numerical Simulation of Unsteady Seepage and Stability Analysis of Unsaturated Soil Slope Subjected to Rainfall
论文作者 陈彦琢
论文导师 张土乔；韩非,论文学位 硕士,论文专业 市政工程
论文单位 浙江大学,点击次数 13,论文页数 76页File Size3147k
2003-02-01论文网 http://www.lw23.com/lunwen_922779792/ 降雨入渗;非饱和土;非稳态渗流;土坡稳定;有限元分析
Rainfall,Unsaturated Soil,Unsteady Seepage,Slope Stability,Finite Element Method
广泛存在于我国南方大部分地区的残积土等粘性土土坡，常在雨季发生滑坡。因此，研究分析降雨对土坡稳定性的影响以及准确预报事故发生的可能性，是当前亟待解决的一个复杂工程问题。常规的土坡稳定性分析方法主要基于饱和土理论和稳定渗流场情况，难以反映降雨作用对土坡稳定的影响。本文针对受降雨影响显著的非饱和残积土土坡，运用饱和—非饱和土壤水分运动的理论和二维非稳态渗流有限元模型，模拟雨水入渗引起的暂态渗流场，将计算所得到的暂态孔隙水压力分布用于考虑了基质吸力影响的土坡稳定安全系数的计算当中，建立了考虑非饱和土土坡从雨水入渗到出现滑坡危险全过程的计算模型。通过实例分析，研究了降雨强度、降雨持时以及土壤渗透性等重要参数对非饱和土坡渗流场分布、发展和对土坡稳定性的影响。本文的研究工作在改进和完善土坡稳定性数值分析方法方面进行了有益尝试。通过对数值算例的精心设计和较为深入细致的分析，对降雨引发非饱和土土坡失稳的机理和规律有了进一步的认识，可为非饱和土土坡稳定分析、滑坡灾害预报和土坡治理等方面提供有用的参考数据，具有一定的理论意义和实用价值。
Most slope failures are caused by the infiltration of rainwater into a slope. Modeling the effects of rainfall on the stability of unsaturated soil slope is an urgent and complicated engineering problem worldwide. The study presented in this thesis concerns this problem by using numerical analyzing methods.Numerical models were used to study how the infiltration into a slope varies with the rainfall intensity,rain fall duration,soil properties and how the infiltration influences the stability of a slope. A numerical program is coded to solve the transient seepage field by using the finite element and finite difference methods based on the saturated-unsatured soil seepage theory. A model for considering the variations of soil weight and shear strength is created/constructed and the corresponding program is coded.The presented study is an attempt on the development and improvement of numerical methods for slope stability analyses. Several conclusions on the characteristics of the slope stability under rainfalls are obtained. The presented methods and models could be widely used for the numerical analyses on the stability of unsaturated soil slopes.

雨水入渗对非饱和土斜坡内孔隙水压影响的研究
The Investigation on the Effect of Rainfall on Pore Water Pressure Within Unsaturated Soil Slopes
论文作者
论文导师 凡友华；殷建华,论文学位 硕士,论文专业 结构工程
论文单位 哈尔滨工业大学,点击次数 10,论文页数 108页File Size1706K
2006-06-01论文网 http://www.lw23.com/lunwen_526965457/
unsaturated soil slopes; pore-water pressure; rainfall pattern; FEM
在降雨对非饱和土斜坡稳定性影响的研究中,对降雨强度、降雨持续时间和降雨量的研究比较成熟,而研究雨型对斜坡稳定性的影响比较少。目前,在研究雨型对斜坡稳定的影响时,大多都是假设理想化的柱状雨型分布的情况下,研究雨型的均匀性对稳定性的影响。而在实际的降雨过程中雨峰出现的次数以及出现的时刻对滑坡的预报和防治是非常重要的。因此,研究一场降雨过程中雨峰在何时出现对滑坡的预报和防治具有重要的理论和实际意义。本文从研究降雨类型对非饱和土斜坡内孔隙水压力的影响入手,来研究雨峰的位置对斜坡的稳定性的影响的。本文主要的研究内容和成果如下: 1)在非饱和土力学的基础上推导了二维渗流控制控制方程的稳态渗流方程和瞬态渗流方程。然后,利用SEEP/W计算软件对非饱和土瞬态渗流稳态进行建模分析,并且提出了在建模过程中使用SEEP/W的一些注意事项。 2)在假设长期降雨过程中前期降雨的分布类型的情况下,通过利用有限元方法计算在给定的边界条件下(包括降雨边界条件)非饱和土斜坡内的渗流过程,得到了不同时刻时孔隙水压力的分布。通过对数值计算结果的分析,表明:在长期的降雨持续期内对于柱状降雨分布类型,可以描述它对孔隙水压力有明显影响的参数为:降雨持续时间和间歇持续时间的比值、在前期降雨过程中每次降雨的降雨强度和持续时间。对于长期的前期降雨的不同分布类型对非饱和土斜坡内孔隙水压力影响最大的情况是:当降雨持续时间与间歇持续时间比较接近时,较大的降雨强度和较长的降雨持续时间。 3)选取了一个降雨强度公式,在此基础上根据Keifer和Chu雨型模型公式计算出了不同时刻下降雨的强度。然后在雨峰相对位置参数r取不同的值时,对不同土的水力学特性,初始条件的情况进行有限元渗流计算。得到了不同的模型参数下孔隙水压力的变化规律。数值计算结果表明:在一定的降雨持续时间内,随着r值的增大,孔隙水压力增加的幅度先增加后减小,即对孔隙水压力影响较大的雨峰时刻为降雨持续期内中间时刻。对于Keifer和Chu雨型当降雨持续期小于12小时时这一规律比较明显。 4)在保持与Keifer和Chu雨型的总的降雨量、降雨持时和峰值强度相同的情况下,设计了一组柱状单峰雨型,计算了雨峰相对位置不同时孔隙水压力的变化,同时也考虑不同的水力学特性和初始条件。并且对两种雨型做
The investigation on the relationship between the stability of unsaturated soil slopes and rainfall mainly focuses on the effect of rainfall intensity, duration and rainfall amounts. But, the effect of the rainfall pattern on the stability of the slopes is considered very little. Currently, when studying the effect of rainfall pattern on the stability of slopes, the effect of the rainfall pattern’s uniformity on the stability of slopes are studied mainly, in the condition of supposing ideal columnar rainfall pattern distribution. However, during the actual rainfall course, the occurrence numbers and moments of rainfall peak are very important to the forecast and prevention of landslide. Therefore, the effect of the occurrence numbers and moments of rainfall peak on pore water pressure within unsaturated soil slopes are investigated. The main research content and result are as follows: 1) The two-dimensional governing equations for steady-state flow and transient flow are derived based on unsaturated soil mechanics. Then, the transient flow is modeled by SEEP/W software, and some advices when the transient flow is modeled are brought forward. 2) Assuming antecedent rainfall distribution pattern during a long-term rainfall, the pore-water pressure within unsaturated soil slope are calculated by the finite element method under boundary conditions and rainfall boundary conditions. The results of the numerical analysis show that the ratio between rainfall duration and rainfall stopping duration can significantly influence the change of pore-water pressure within an unsaturated soil slope. If the rainfall duration is almost the same as rain stopping duration, the more intensity and duration of every rainfall event, the larger change of pore-water pressure. 3) The rainfall intensity formulation is identified, and according to Keifer&Chu rainfall pattern’s principle, the intensity of different rainfall time can be calculated. Then, the numerical seepage analysis can be carried out with different r under different soil hydraulic prosperities and initial conditions. The results of numerical analysis show that the parameter of rainfall peak r can significantly influence the change of pore-water pressure. For Keifer&Chu rainfall pattern, when the rainfall duration is less than 12 hours, the difference