加强型泥石流柔性防护体系抗冲击性能研究

发布时间：2018-01-12 03:35

本文关键词：加强型泥石流柔性防护体系抗冲击性能研究　出处：《兰州理工大学》2016年硕士论文　论文类型：学位论文

【摘要】：近年来,甘肃省泥石流灾害的频繁发生,给当地人民的生命财产安全造成了严重的危害。舟曲8.8特大泥石流灾害表明,泥石流中的大块石是造成防治结构损毁的最主要原因。因此,研究在泥石流大块石冲击作用下防治结构抗冲击性能有着重大的意义。在众多防治结构中,泥石流柔性防护体系具有造价低、施工简便、易于维护、场地适应性强和对环境景观不构成破坏等优点。在国外的防治工程上得到了广泛的推广应用,然而,学术界对其研究还不够深入,尤其是对抵抗泥石流大块石冲击性能的研究基本处于空白阶段。从结构和力学的角度,采用显示动力非线性软件ANSYS/LS-DYNA进行数值模拟,对泥石流柔性防护体系受冲击作用时的动力响应特征和失效破坏模式展开研究。主要研究内容包括以下几方面:(1)研究分析冲击作用在不同部位时,泥石流柔性防护体系的动力响应特征。对防护体系的能量转换、变形和构件的轴力变化规律进行对比分析,并评估防护体系的抗冲击性能。改变冲击速度,分析其对泥石流柔性防护体系抗冲击性能的影响,并得出防护体系的失效破坏模式。结果表明:防护体系中支撑索是耗能能力较强的构件。其中冲击部位、支撑索约束端部和连接点处动力响应较大,建议在工程设计中予以加强。(2)提出受力状态更为合理的结构形式即带竖向吊索的加强型泥石流柔性防护体系。通过数值模拟,将加强型防护体系与普通型防护体系的动力响应进行对比分析,评价加强型防护体系的抗冲击性能。改变冲击速度,分析其对加强型防护体系的抗冲击性能影响,并得出加强型防护体系的失效破坏模式。结果表明:增加竖向吊索后,间接地保护了环形网不被破坏,且防护体系的抗冲击能力明显增强了。(3)多块石随机分布且同时冲击作用在加强型泥石流柔性防护体系时,对防护体系的能量、变形和构件轴力的动力响应特征进行分析,并评估其抗冲击性能。本文的研究成果为泥石流柔性防护体系的工程设计提供了一定的技术参考,为日后的工程应用奠定一定的基础。
[Abstract]:In recent years, the frequent occurrence of debris flow disasters in Gansu Province has caused serious harm to the safety of local people's lives and property. The rock mass in debris flow is the main reason to prevent the structure damage. Therefore, it is of great significance to study the anti-impact performance of the structure under the impact of debris flow rock mass. The flexible debris flow protection system has the advantages of low cost, simple construction, easy maintenance, strong site adaptability and no damage to the environmental landscape. It has been widely used in prevention and control projects abroad, however. Academic research on it is not deep enough, especially the research on the impact performance of debris flow blocks is basically blank. From the point of view of structure and mechanics. The dynamic nonlinear software ANSYS/LS-DYNA is used for numerical simulation. The dynamic response characteristics and failure failure mode of debris flow flexible protection system under impact are studied. The main research contents include the following aspects: 1) study and analysis of impact in different parts. The dynamic response characteristics of debris flow flexible protection system. The energy conversion, deformation and axial force change of the protection system are compared and analyzed, and the impact resistance performance of the protection system is evaluated and the impact velocity is changed. The impact on the impact resistance of the flexible debris flow protection system is analyzed, and the failure failure mode of the protection system is obtained. The results show that the bracing cable is the component with strong energy dissipation capacity in the protective system. The dynamic response of the restrained end part and the connection point of the bracing cable is large. It is suggested that the reinforced debris flow flexible protection system with vertical slings should be put forward as a more reasonable structural form in engineering design. Numerical simulation is carried out. The dynamic response of the reinforced protection system and the common protection system are compared and analyzed to evaluate the impact resistance of the enhanced protection system and change the impact speed. The impact on the impact resistance of the reinforced protective system is analyzed, and the failure failure mode of the reinforced protective system is obtained. The results show that the ring network is protected indirectly by increasing the vertical slings. And the anti-impact ability of the protective system obviously enhanced the impact energy of the protection system when the multi-block stone was randomly distributed and simultaneously impacted on the enhanced debris flow flexible protection system. The dynamic response characteristics of deformation and axial force are analyzed and its impact resistance is evaluated. The research results in this paper provide a certain technical reference for the engineering design of debris flow flexible protection system. To lay a foundation for future engineering application.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：P642.23

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