大箐泥石流对桥墩的冲击动力作用及灾害治理措施研究

发布时间：2018-05-14 06:42

本文选题：泥石流 + 危险区划　；参考：《昆明理工大学》2017年硕士论文

【摘要】：我国西南山区是泥石流灾害比较发育的地区。随着西南山区经济的发展,交通路网的建立,公路、铁路桥涵等道路关键工程遭遇泥石流灾害的频率也越来越高,因此对道路桥梁泥石流灾害的研究也愈来愈重视。永盛县热河古格村大箐流域曾多次爆发泥石流灾害,造成省道S220过沟桥涵严重淤堵,下游沿岸的农田被淤埋,成为威胁省道S220过沟桥涵及古格村村民生命财产安全的重大地质灾害隐患点。本文以大箐泥石流和省道S220桥梁为研究对象,对大箐泥石流的形成背景及危害进行了介绍,并从大箐泥石流形成的地形条件、物源条件和水源条件分析入手,对大箐泥石流的启动模式、物性特征以及泥石流的发展趋势进行了详细论述,计算了大箐泥石流的主要动力学参数,并对泥石流的危险区进行了划分,有针对性的调查了大箐泥石流对省道S220过沟桥涵的破坏方式。在上述分析论证的基础上,采用ANSYS Workbench进行瞬态动力学分析,研究了古格大桥桥墩在泥石流整体冲击作用与大石块冲击作用下的响应,获得了桥墩在不同荷载工况组合条件下的变形和受力状态,并对泥石流冲击作用下桥墩的破坏规律及主导因素进行了详细分析。基于泥石流与桥墩的双向流固耦合分析结果,对泥石流作用区桥梁墩台的防护措施进行了深入探讨,列举了各种措施的适用条件与特点,并对比分析了相同截面面积下,圆形桥墩、矩形桥墩、圆端形桥墩抵抗泥石流冲击性能的高低,对泥石流作用区桥梁桥墩的设计及防护措施的选择具有重要的指导意义。为切实有效的保障省道S220桥涵及沿岸村民的生命财产安全,参考类似泥石流沟谷的防治经验,选择“谷坊坝、拦挡坝+束流堤、防护堤”以拦排为主的工程治理措施对泥石流进行治理,并对拦挡措施选择最不利的荷载组合进行稳定验算,计算结果满足设计要求。
[Abstract]:The mountainous area of southwest China is a relatively developed area of debris flow disaster. With the development of the southwest mountainous area economy, the establishment of traffic network, the frequency of the debris flow disaster in the key projects such as highway, railway bridge and culvert are becoming higher and higher, so more and more attention has been paid to the study of the road bridge debris flow disaster. Debris flow disasters broke out many times in the Daqing Valley of Gehe Guge Village, Yongsheng County, resulting in serious siltation of the provincial highway S220 crossing gully bridges and culverts, and buried farmland along the lower reaches of the river. It has become a major geological hazard hidden danger point that threatens the safety of life and property of villagers in S220 crossing ditch bridge culvert and Guge village. This paper takes Daqing debris flow and provincial highway S220 bridge as the research object, introduces the formation background and harm of Daqing debris flow, and starts with the analysis of terrain condition, material source condition and water source condition of the formation of Daqing debris flow. The starting mode, physical properties and development trend of Daqing debris flow are discussed in detail, the main dynamic parameters of Daqing debris flow are calculated, and the dangerous areas of debris flow are divided. The damage mode of Daqing debris flow to S 220 bridge and culvert was investigated. On the basis of the above analysis and demonstration, the transient dynamic analysis of the pier of Guge Bridge under the impact of debris flow as a whole and the impact of large rocks is studied by using ANSYS Workbench. The deformation and stress state of the pier under different load conditions are obtained, and the failure law and leading factors of the pier under the impact of debris flow are analyzed in detail. Based on the results of two-way fluid-solid coupling analysis of debris flow and pier, the protective measures of bridge pier and abutment in debris flow area are discussed in depth, the applicable conditions and characteristics of various measures are listed, and the same cross-section area is compared and analyzed. The resistance of circular pier, rectangular pier and round end pier to debris flow impact is of great significance to the design of bridge piers in debris flow zone and the selection of protection measures. In order to ensure the life and property safety of the bridge and culvert of provincial highway S220 and the villagers along the coast, referring to the prevention and cure experience similar to the debris flow gully, "Gufang Dam" and "Gufang Dam" are selected. The embankment is controlled by the engineering measures of blocking and drainage, and the stability check calculation of the most unfavorable load combination of the blocking measures is carried out, and the calculation results meet the design requirements.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U443.22;U445.75

【参考文献】