【作者】 郑书彦；

【导师】 李占斌；

【作者基本信息】 西北农林科技大学 ， 土壤学， 2002， 博士

【摘要】 中国黄土高原地域广阔，土层深厚，干旱半干旱气候和黄土的特殊性质导致该地区水土流失非常严重。由于长期的水土流失，形成了沟壑纵横的破碎地貌景观，滑坡、崩塌等重力侵蚀非常活跃。滑坡侵蚀是重力侵蚀的主要类型之一，是黄土高原陡坡侵蚀产沙和沟道侵蚀产沙的主要来源。由于种种原因，重力侵蚀研究相对滞后，很多方面亟待深入的探讨。本文在前人大量研究的基础上，通过现场调查、数值模拟、典型案例剖析等途径，在分析了黄土高原典型滑坡侵蚀成因、典型地区滑坡侵蚀分布的基础上，尝试探索土壤侵蚀学与滑坡学之间的联系，初步建立了滑坡侵蚀分析研究．体系；用数值模拟方法研究了典型滑坡侵蚀体力学机制和运动过程；利用信息量理论对典型区域滑坡侵蚀进行定量评价研究等。通过研究取得以下主要结果： 1．应用土壤侵蚀学、地质学、地貌学等理论，给出了滑坡侵蚀的定义、形态要素、分类、灾害链、形成条件、诱发因素及与其它重力侵蚀的区别等；运用多种手段对典型滑坡的地层岩性、物理力学性质进行了现场调查与实验，建立了用于典型滑坡侵蚀计算的地质模型，初步建立了滑坡侵蚀的分析研究体系。 2．利用弹塑性力学理论，建立了典型滑坡侵蚀的数学力学模型。通过有限元数值模拟，计算分析铜川市典型滑坡侵蚀体的网络变形、主应力、主应变、剪应力、安全率、破裂面上应力分布等，得到典型滑坡侵蚀体不同部位的力学状态全面系统的把握。 3．利用运动学基本定律，建立了典型滑坡侵蚀的运动学模型。通过离散单元法数值模拟，对滑坡侵蚀实例进行滑坡破坏后的运动过程仿真，得出了边坡破坏后滑坡侵蚀体运动过程中各块体不同时刻的运动状态、移动轨迹、接触力与角—边接触关系、形心平均主应力、形心平均位移、块体力矩、块体作用力、块体转角、速度、加速度等的历时曲线，模拟仿真滑坡侵蚀体动态运动过程，在此基础上得到了滑坡侵蚀体运动过程主要分为五个阶段的结论，对滑坡侵蚀体的滑动过程有了一个新的认识。 4．利用信息量理论，建立了典型地区滑坡侵蚀定量评价模型。影响滑坡侵蚀的因素是多方面的，且各因素对滑坡侵蚀的贡献不同。影响滑坡侵蚀的因素状态 郑书彦傅上论文：渭坡侵蚀及其动力学机制与定屋评价研究从大到小为地下水出露在黄土底部的基岩面上，植被盖度小、人类活动强度大、沟谷密度密、地层结构为黄土与基岩、相对高差乃0队地形坡度2045”、地形坡度＞45”、地震加速度高、地下水出露在黄土坡体中共10个因子状态。 5．本文通过现场调查和资料分析得出，在铜）；怖区82．skin‘的面积上，滑坡侵蚀面积 44·skin’，占 53·9％，无滑坡侵蚀的面积 38·oh旷，占 46·1％。铜川市区 沁滑坡剧烈侵蚀区面积13．00km‘，占15．76％，强烈侵蚀区面积20．00km’，占24．24％，中度侵蚀区面积25．25km＼ 占30．61％，轻度侵蚀区面积6．00km＼ 占7．27％，微弱侵蚀区面积 18．25k旷，占22．12％。铜川市区滑坡侵蚀中等以上强度区面积58．25km’，占 70．61％。铜JI怖区共有滑坡、崩塌、滑塌 451个，其中滑坡 127个（老滑坡 43个、新滑坡 84个），占 28．2％，滑塌52个，占 11．5％，崩塌 272个，占60．3％。崩塌的数量很多，但规模较小（崩塌侵蚀量148．4万T，仅占1．19％）：滑塌的数量和侵蚀量（74O．5万T，5．96％）也较少；滑坡的个数虽少，但侵蚀量却很大 （1154．6万 T，92．85％），可见铜川市区滑坡侵蚀程度非常强烈。运用本文建立的典型地区滑坡侵蚀定量评价模型，得出了铜川市区滑坡侵蚀强度分布图，经与实测资料对比，模型计算的可靠性和可信度较高。更多还原

【Abstract】 The loess is thick and widely distributed on Loess Plateau in China. The drought and semi-drought climate and the special properties of loess result in serious Soil and water loss in the area. Therefore, the geomorphic landscape is usually characterized by gullies, where me gravity erosion such as slide and collapse are very active. Slide erosion, the main resource of gully sediment yield, is one of the most important types of gravity erosion. However, the gravity erosion, of which many aspects still need further research, has been lagged because of various reasons. In mis paper, firstly, with the achievements of many predecessors, based on the analysis of the erosion causes of loess plateaus and the distribution of slide erosion in typical areas by methods of field investigation, numeric analysis and typical cases analysis, the slide erosion analyzing system is tentatively founded which can express the relationship between soil and slop erosion. Secondly, the dynamical mechanics and movement of typical slide erosion body is deeply researched by method of numeric analysis. Finally, the regional slide erosion is quantitatively evaluated by method of information quantity theory. The main achievements are as follows:1. It is put forward mat the definition of slide erosion, the shape elements, classification, catastrophic chain, formation condition, inductive factors, the differences between slide erosion and other gravity erosion are suggested, based on the theories of soil erosion, geology, and geomorphology The geological model to calculate the slide erosion is founded on the basis of many investigation and testskof the litho logic characters and mechanical properties of typical slide, based on which the slide erosion analyzing system is set up.2. The mathematical-mechanical model of slide erosion is founded on the basis of the elastic-plasticity theory. Through the calculation of the network distortion, principal stress, principal strain, shear stress, safety rate and the stress distribution on the fractured surface of the typical slide in Tong-chuan city by finite element method, the mechanical situation of different parts of the typical slide are finally mastered.3. Based on the principals of kinematics, the kinematics model of slide erosion is founded. After the discrete units simulation of the movement of collapsed slide, the duration curves of motion states,moving pathways, the relationship between contact force and angle-edge contact, mean principle stress, mean displacement, force moment and acting force, striking angles, velocity, accelerated velocity of different parts of the sample slide are obtained, as a result, the process of slide movement is divided into five stages, which is a new achievement to the slide erosion process.4. The model of quantitatively evaluating slide erosion is founded according to the information quantity theory. There are many factors that influence slide erosion, which are groundwater on the bedrock surface, thin plant cover, heavy human activity, high gully density, loess and bedrock layers, difference in elevation (which is bigger than 50 meters), degree of slide (between 20?and 40?), degree of slide (which is bigger than 45?), high-accelerate earthquake, groundwater inside the loess slide, of which the formers contribute much more than the laters to slide erosion.5. Field investigation and numeric analysis shows that The total area area of the studied zone in Tong-chuan is 82.5 square kilometers, where slide erosion area is 44.5 square kilometers, occupying 53.9% of the total area; the area without slide erosion is 38.0 square kilometers, occupying 46.1% of the total area; the serious slide erosion area is 13.0 square, occupying 15.76% of the total area; the drastic erosion area is 20.00 square kilometers, occupying 24.24% of the total area; the middle erosion area is 25.25 square kilometers, occupying 30.61% of the total area; the mild erosion area is 6.0 square kilometers, occupying 7.27% of the total area; the weak erosion area is 18.25 squa更多还原