【作者】 温克兵；

【导师】 陈志新；

【作者基本信息】 长安大学 ， 地质工程， 2006， 硕士

【摘要】 黄土的湿陷性作为影响工程建设的不利因素一直是人们研究的热点和重点之一。为消除黄土的湿陷性，国内外很多学者和工程人员在探索研究和工程实践中发明和总结了大量的湿陷性黄土地基处理方法。强夯法是处理湿陷性黄土地基的有效方法之一，以其经济易行、效果显著、施工便捷、节省材料、质量容易控制、施工周期短等优点迅速得到了推广和广泛的应用。充分挖掘和利用大量已经完成的强夯加固地基成功经验，对进行强夯加固深度研究有着重要的实际意义。 本文在系统、深入地分析研究了强夯加固非饱和土与饱和土原理的基础上，从宏观(如冲击力、应力波的传播对土加密的影响等)和微观(如土颗粒的重新排列、连接等)两个方面对强夯的加固机理进行了论述。并从土的动应力场、干重度、土位移场及孔隙水压在加固区深度和广度上的变化分析研究了强夯加固模式，将加固范围根据加固程度划分为主压实区，次压实区，压密、挤密、松动区和振动影响区。 随后，对强夯加固时夯锤与地面接触的瞬态动力进行了分析探讨，并运用损伤力学的观点，对强夯作用下湿陷性黄土的土体结构损伤破坏进行了研究。引用钱德拉·德赛(Chandra S．Desai)提出的扰动状态概念(disturbed state concept，DSC)对土体损伤破坏加以分析，并通过工程实例中强夯前后湿陷性黄土的干重度γd、孔隙比e、压缩系数α、压缩模量E_s的变化将土的损伤区域划分为强损伤带、损伤带和影响带，分析表明它们与加固模式下的加固区域对应吻合。 针对目前强夯有效加固深度的计算和预估方法繁多复杂的特点，本文运用模糊相似优先的概念，综合考虑各种影响因素的不确定性，构造一个强夯范例检索模型，提出了强夯有效加固深度的范例推理预估方法。在该模型中，提出根据变权的概念采用频数统计的原理计算权重的方法，体现了权重对影响因素的敏感性，很大程度上克服人为主观因素的影响，使之更客观化。本方法推理原理简单，使用方便，通过工程实例对该方法进行了验证，取得了较理想的效果，具有实用价值。更多还原

【Abstract】 Collapsibility of loess is always a popular field because it is one of the disadvantages for engineering construction. In order to eliminate it, a mass of domestic and foreign scholars and engineers have developed many methods. Dynamic consolidation is one of the methods and has been promoted rapidly and applied widely for its merits such as economy, remarkable effect and advantageous construction etc. Experience from the completed construction with the dynamic consolidation could apply to the prospective projects.This article studied the different principles by systemic and embedded ways for consolidating the saturated soil and unsaturated soil. At the same time, it elaborated the reinforcement mechanisms from two aspects include macroscopic such as impulse, influence of the stress wave to consolidate soil and so on and microscopic such as soil-pellet rearranged, reconnection and so on. And the reinforcement pattern to dynamic consolidation has been analyzed according to the remarkable changes of soil characters, for example dynamical field, dry-consistency and pore water pressure. Then the reinforced scope has been divided up to the primarily compaction area, the inferior compaction area, the loose area and the influenced area.Then, the article analyze and discuss the instant-dynamical when the hammer contact the ground, and using the viewpoint of damage mechanics and quotes the disturbed state concept proposed by Chandra S. Desai to study the damage of collapsible loess structure. Dividing the soil damage region for the belt of strong-damages, the belt of damages and the influence belt, the conclusion indicated they tally with the reinforcement pattern under reinforcement region correspondence. In view of the present methods complicatedly to calculate and estimate effective reinforced depth of dynamic consolidation, in this article, a model based on case-based reasoning has been created to estimate effective reinforced depth utilizing the concept of fuzzy preferred ratio, considered kinds of uncertain influence factors. the approach is simple and convenient to use. In this model, a new way to calculate the weight was proposed, it will overcame the subjective influence and more objective. It has obtained the ideal effect and practical value through through the confirmation with project example.更多还原