滚石冲击特性研究
文献类型：学位论文
| 作者 | 沈均 |
| 学位类别 | 硕士 |
| 答辩日期 | 2009 |
| 授予单位 | 中国科学院水利部成都山地灾害与环境研究所 |
| 授予地点 | 成都 |
| 导师 | 何思明 |
| 关键词 | 滚石 冲击与回弹 数值模拟 棚洞 混凝土路面 |
| 其他题名 | Research on Impact Characteristics of Rock-fall |
| 学位专业 | 岩土工程 |
| 中文摘要 | 滚石是我国西部山区常见的一种地质灾害，它分布范围极广，发生突然，频率高，严重威胁其周围的人类以及各种构筑物。尤其是在汶川大地震之后，地震荷载作用之后，岩土体结构大多遭受不同程度的破坏，在外界营力的作用下，滚石发生的频率以及产生破坏的强度将大幅度提高。而目前，国内外有关滚石的理论研究比较薄弱，以致滚石灾害的防治工作受到严重的影响。 在山区滚石灾害防护工程中，滚石拦截系统恰当位置的选择及其拦截高度的确定非常关键，它直接关系到拦截系统的成败。而影响拦截系统设计的因素很多，其中滚石在坡面上的运动轨迹是关键。本文将以弹塑性接触理论为基础，研究了滚石法向恢复系数、切向恢复系数的计算方法，运用运动学的基本方程研究了滚石在坡面上的运动特征，推导了相关的公式。通过具体算例的分析，显示了理论的合理性。 在Hertz弹性接触理论研究基础上，通过修正的Hertz接触理论以及相关的弹塑性接触碰撞理论，根据准静态原则，推导滚石法向接触的弹塑性接触力以及接触变形方程。通过能量守恒建立了滚石法向冲击的冲击力以及冲击变形位移的计算公式，通过数值模拟比较，两者结果吻合较好。 棚洞是滚石防治的最有效工程措施之一。本文对滚石冲击棚洞进行数值模拟，研究了滚石在不同的冲击角度下，冲击力、冲击深度与时间的关系，以及棚洞混凝土顶板在最大冲击力以及最大冲击位移情况下的变形挠度。得出滚石冲击弹坑形状以及冲击过程中的回弹等随角度的关系。通过该理论的研究，可以为棚洞防治设计提供理论基础。 为了揭示滚石冲击动荷载下混凝土路面结构的力学响应，基于动力三维有限元，考虑材料的弹塑性，拟定滚石以不同速度冲击混凝土路面时，路面结构的受力和变形特征。研究发现，随着冲击速度的提高，混凝土接触面法向应力显著增加，混凝土接触面产生显著的塑性变形。通过该理论的研究，可以为滚石灾害多发区混凝土路面设计提供理论依据。 |
| 英文摘要 | Rock-fall is a frequent disaster in western mountainous region. It badly threaten the people and the varied constructions around it because of its wide distribution range, abruptness and high frequency. Especially after Wenchuan earthquake, under the action of seismic loads and other external forces, the geotechnical structures have been suffered varying degrees of damages. The frequency of occurrence and the resulting damage will be increased significantly. At present, due to the weakly theory research, the prevention and cure means of rock-fall have been affected badly. In the design of rock-fall protection project, the proper location and reasonable intercepting height of the intercepting system are most important factors，which directly relate to the system success or failure. There are many factors which can influence the system, but among them the stone’s motion track on slope plays a key role. Base on the elastic-plastic contact theories, the calculation model of restitution coefficient both in normal and tangential impacting direction are studied. Then apply the fundamental kinematical equation in studying the stone’s motion characteristic, and deduce the related formulas. At last, by calculating and analyzing a specific example, the theory is proved to be reasonable. On the basis of Hertz elastic contact theory and correctional Hertz contact theory and relative elasto-plastic impact theories, according to quasi-static Principles, the author deduced the elasto-plastic equations of normal impact forces and deformations. Via energy conservation, the author gives the computing formula of normal impact forces and deformations of rock-fall impact. The results are the same with the numerical simulation results Hangar tunnel is one of the most effective engineering control measures. Via numerical simulation, we studied the relationship between impact forces and deformations and the deflection deformations of the concrete plate under different impact angles of rock-fall. The author obtained the relationship between impact crater and rebound and different impact angles. Through researching this theory, it can give us a theory foundation to design the hangar tunnels In order to explain the mechanical behaviors of concrete pavement structure under impact load of rock-fall，the stress and deformation characteristics of pavement structures under the impact load were studied based on 3D elastic-plastic dynamic finite element method．The results indicate that with the increase of impact velocity，the plastic deformation of concrete enhance greatly. Through researching this theory, it can give us a theory gist to design the concrete pavement structure. |
| 学科主题 | 岩土力学 ; 灾害学 |
| 语种 | 中文 |
| 公开日期 | 2010-10-13 |
| 分类号 | TU4;P64 |
| 源URL | [http://ir.imde.ac.cn/handle/131551/2176]  |
| 专题 | 成都山地灾害与环境研究所_成都山地所知识仓储（2009年以前） |
| 推荐引用方式 GB/T 7714 | 沈均. 滚石冲击特性研究[D]. 成都. 中国科学院水利部成都山地灾害与环境研究所. 2009. |
入库方式： OAI收割
来源：成都山地灾害与环境研究所
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