泥石流冲击荷载下空间索网防护结构的动力性能与实验研究

China is one of the counties with the most serious geological disasters in the world. the loss caused by debris flows is very serious in recent years. Based on thorough investigation and study on the protection structure of debris flow in domestic and foreign, the innovational space cable net structure has been proposed. Considering the real project situation of the existing debris flow protection structure, systematically research on calculation method of debris flow characteristic parameters under different geological environment can be done. Based on the use of space cable net structure characteristic of light weight, high strength, good overall deformation resistance and shock resistance, and the advantages of convenient construction, space cable network protection system have been put forward. This kind structure not only has the behavior to resist impact of debris flow but also have achieved the separation of water and stone. Theoretical analysis and experimental research including the space dynamic response of the cable net under the debris flow impact, structural failure mode and failure pattern, study the relationship between impact resistant stiffness and impact to this kind of new structure system will been done. With the superior performance of the new FRP material, new connection nodes and energy-consuming devices will be developed. Structure design principles and design methods new type of space cable network under the impact load of debris flow will be established. The scale model experiment of will be done to verify the validity of this kind of structure. Besides, deformation and energy dissipation properties of this kind of new type of structure will be controlled using advanced energy element to improve impact capacity of the structure. The research result will be provide theoretical basis for the theory and design method of cable network structure to prevent and control of landslide engineering.

我国是泥石流灾害最为严重的国家之一，近年来泥石流造成的损失十分严重。本课题在对国内外泥石流防护体系调查研究的基础上，结合泥石流防治工程的实际情况，结合不同地质环境下泥石流特征参数（包括流速和冲击力）；利用空间索网结构的特有的轻质高强、整体抗变形能力和抗冲击性能好、施工便捷等优点，提出既能抵抗泥石流冲击作用且实现水石分离的新型空间索网防护体系，结合新型FRP材料的优越性能开发新型连接节点和耗能装置，进行新型柔性防护结构体系抗冲击性能的理论分析和实验研究，探索钢结构和FRP索网结构在泥石流冲击作用下的动态响应、结构破坏模式和破坏形态，研究结构抗冲击刚度与冲击力之间的关系，建立泥石流冲击作用下新型空间索网防护结构的设计准则和设计方法；并通过等效荷载模式的缩尺模型实验研究，验证结构的有效性；对新型结构的变形和耗能性能进行控制，为索网结构冲击理论与设计方法提供理论依据，为泥石流工程防治提供技术支撑。

课题针对泥石流大块石对防护工程的破坏作用，利用柔性索网结构的轻质高强、抗变形能力大、抗冲击性能好、施工便捷等优点，提出了抵抗泥石流冲击作用且实现水石分离的系列新型索网防护体系，包括柔性索网、刚柔组合型索网和刚性格栅3类防护体系，其中柔性索网结构体系包括：钢筋索网体系、钢绞线柔性索网、钢丝网、CFRP加强型钢筋索网、CFRP复合钢板网、耐候钢板网和纤维复合材料索网7种类型；组合型索网体系为钢管柱-索网；刚性格栅包括装配式桩林和管翼缘柱格栅坝。.针对以上各种柔性防护体系进行了多工况下抗冲击性能理论分析和实验研究，利用ANSYS/LS-DYNA分别对所提出的3类新型防护体系进行冲击荷载作用下的动力响应和参数分析，探讨了泥石流冲击荷载下各类体系的破坏规律，分析了网孔尺寸、冲击能量、冲击位置等参数对结构动力响应的影响，探讨了结构的破坏机理、破坏模式和能量转化规律，得到各类柔性防护体系在泥石流块石冲击作用下的动力响应。.通过9x6组索网体系的各种材料性能实验，包括钢筋、钢绞线、CFRP加强型钢筋、CFRP复合钢板、耐候钢板和纤维复合材料6种材料，研究了不同柔性材料及组合对构件的动力性能。利用自主设计的冲击试验台开展系列试验研究，对提出的柔性索网、刚柔组合型索网和刚性格栅3类防护体系进行了系列实验研究，完成了10种类型近50个构件及结构模型实验，得到了单索、索网、组合柱-索网以及格栅坝在泥石流冲击荷载作用下的动态应变、动态位移、加速度峰值等，验证结构抗冲击能力的有效性。考虑泥石流的室外环境，提出耐候钢板网体系，通过4组干湿交替加速腐蚀试验得到腐蚀率的退化关系，进行了11组耐候钢板网体系分析与试验研究，对装配式桩林及管翼缘的钢管混凝土格栅坝进行构件截面优化和抗冲击性能研究，通过实验验证了结构抵抗泥石流冲击的能力。.研究结果表明：提出的3类新型柔性防护体系能够明显减轻泥石流冲击的破坏作用，有效地提高防护结构的抗冲击能力，为进一步的工程应用提供了理论依据。