【作者】 张信贵；

【导师】 吴恒；

【作者基本信息】 广西大学 ， 结构工程， 2002， 博士

【摘要】 随着城市建设的发展和城市人口的日益增多，城市区域的“三水”循环系统被扰动，地下水的化学组份发生变异。城市建设是日复一日的进行，人类活动对地质环境的扰动不可能是一个常量等事实，则水土之间的不平衡状态就持续存在。尽管地下水与地基土体之间的相互作用是长期的、缓慢的，但与土体形成和经历的整个地质历史进程的水土作用相比，水化学环境变异是显著且短暂的，水土作用将会在短时期内进行量的积累，从而使土的性质达到质的变化。研究常温、常压城市环境下的水土作用将有助于预测城市区域建筑环境和建筑地基的变形和稳定问题。该项研究已日益受到国内外专家学者的关注，是工程地质学家在研究城市地质环境稳定性问题时应当回答的重要内容。此项研究为城市建设中的防灾减灾提供理论根据，是防止城市地质灾害产生和保证城市安全的前提，是使城市可持续发展的基础。 基于上述观点，本文针对研究因城市建设导致的地下水化学组份变化对粘性土结构强度影响及作用方式的变化，以城市区域地下水的化学作用入手，剖析土颗粒间的连接作用及胶结物作用。利用现代测试与试验技术，通过构筑多类型的室内模拟环境，着重从土的细观结构出发，研究城市区域下的水土作用及土体的力学特性及结构强度。 广西大学博士学位论文 文章从自然界或工程上的一些具体现象或问题出发，抽象出域市区域水。相。作用本质在于地，水。境一鞭一强度间存在着内在联一‘“”一‘”一’『”’“————一“——‘”“”一’－炫构——一‘”‘“一口”“—一系，指出地下水化学场变异通过对土结构的调整来强化与弱化土性。 结合南宁市具体的地下水环境，对域市区域地下水环境背景及地下水化学场变异的主要因素进行了分析，以南宁市为例对域市区域地下水化学场的演化规律进行了定量研究与分区。通过对地下水化学组份变量的因子分析，建立了城市区域水土作用的评价指标体系。通过水化学组份与土强度间的相关性分析，提出水化学组份的变异可以映射水土作用下土强度的变异； 从水土作用的理论出发，分析了域市建设、地下水环境变异与土结构强度间的相互关系，研究了土的结构尺度及其在水土作用中的意义：总结了土的结构强度的来源、定义了土细观结构的物理涵义井划分了土的结构尺度及层次、归纳了水土作用的四个基本形式、讨论了水土作用的化学作用机理。由理论分析提出，域市常温、常压、缓慢的地下水变异环境下的土体性质的可变性将由结构一尤其是细观结构来度量，进而提出细观结构是水土作用发生与发展的“平台”和主要场所、是水土作用效果表现的载体，水土相互作用分析可通过土细观结构这个桥梁来进行，由此建立了细观结构变异数学模型以及变形的预测模型； 试验研究表明水土作用引起土的结构变异是存在的，而且结构变异可以被认识，并可以通过一定的测试手段来显现。扫描电镜技术证实了水土作用下结构变异的存在；义射线衍射技术研究了各结构层次变异的贡献率问题；OT技术通过研究可溶蚀相溶蚀与颗粒宏观分散，利用土体体 且互 广西大学博士学位论丈变率和 CT值变化率存在统一性规律，宝量解释了水环境变异引起土体孔隙及潜在变形的细观结构变异规律；扫描隧道显微镜技术初步定量测定了水化学场变异引起的颗粒间距离变化的规律，为进一步揭示土结构变化的规律提供了新途径； 水土作用下的力学特性试验证实了可溶相溶蚀是水土作用产生细观结构质变的一个重要原因，孔隙比变化是细观结构变异的外在表现形式。通过建立细观结构变异度概念，研究了组份在水土作用下随环境变异显著性及对细观结构的贡献。提出细观结构变异具有1 化”或“弱化”效应及遗传性。试验得出短期水土作用下两类变形特征规律，发现长期水土作用下土体存在“世纪性”的变形增长，变形特征兼有短期与长期水土作用的变形特征，是两种变形特征的复合体。水土作用发生时细观结构扰动的效果与土体上是否作用荷载有关，根本的区别在于细观结构的变异或破坏是否得到外界因素的补偿。通过檬拟CO。分压增高的试验，揭示出水土作用的宏观效果一土的应力一应变关系及土的结构强度的变化，在宏观上解释了地下水变异一组份一细观结构一上体结构强度相互间水土作用的本质。更多还原

【Abstract】 With the development of the city construction and increasingly population, the ground water, surface water and atmospheric water " three-water " circle system are interrupted, groundwater’s chemistry component is changing. City construction goes on day after day, the affection that human’s movement having on geological environment is not a constant, so the imbalance in the soil and water continually exists. Though groundwater -soil interaction is long and slow, It is marked and transient the water’s chemistry change comparing to the interaction between the water and soil during whole geological history process. The results of quantity accumulated in a short time will reduce to the soil’s nature change. Research on which under normal temperature and press in city will help forecasting the problems of foundation’s distortion and stabilization in city construction environment. It is an important content which engineering geologist in the studying field of city geological environment stability should answer, and experts inside and outside pay increasingly attention to it. This research provides theory for preventing and decreasing disaster, it’s also the precondition and foundation for the city’s continuous development.Basing on the above viewpoints, this paper aims at affection that groundwater’s chemistry component change having on fine-grained soil structures strength, and analyses the connection and cementation between soil granules proceeding with water chemistry function. By modern test and experiment technology, building many kinds of indoor simulative environment, emphasizing on soil Mini Scale structure, it study soil-waterIVinteraction, soil’s mechanical properties and structures strength.This article draws out that the water-soil interactive essence is at innerrelations among groundwater environment~componen -- strength, from somestructurephenomenon and problems in nature or engineering project, pointing out that groundwater chemistry field variation will strengthen or weaken soil character through the adjustment on soil structure.As far as Nanning groundwater environment is concerned, the background of groundwater environment and factors of its chemistry field variation are analyzed, it gives rational research and division on evolution rule of groundwater chemistry field as Nanning a example. It sets up a evaluated system by analyzing groundwater chemical components, through studying pertinence in water chemical component and soil strength, it also puts forward that water chemical change can map soil strength variation under water-soil interaction.From the theory of the water-soil interaction on, the interrelation of city construction, the variation of groundwater condition and the soil structure strength is analyzed and that the measure of soil structure and the significance which is by the water-soil interaction is studied in this paper. At the same time, in the paper: the recourse of the soil structure strength is summarized; the physical meaning of soil mini-scale structure is defined; the measure of soil structure is classified; the four basis forms of the water-soil interaction is induced; the chemistry mechanism of the water-soil interaction is discussed. As result of above, soil character’s variation can be measured by structure, especially by mini-scale structure, under circumstance of normal temperature, normal pressure and slowly groundwater variation, and so mini-scale structure is platform and main location for water-soil interaction taking place and developing, also the carrier of their effect .The water-soil interaction can be analyzed by the soil mini-scale structure, from this the mathematical model on the variation of mini-scale structure and the deformation forecast model can be established.It is manifested by tests and researches that there is the variation of soil structure caused by water-soil interaction, moreover, which can be recognized and showed by some tests. It can conform the existence of the structure variation by water-soil interactio更多还原