五里沟泥石流对泸定互通综合体及弃土坝危险性评价

发布时间：2018-04-02 15:09

本文选题：雅安-康定高速公路　切入点：泸定互通综合体　出处：《成都理工大学》2015年硕士论文

【摘要】：泸定互通综合体是雅安至康定高速公路交通转换服务设施重要组成部分,更是后期二郎山超特长隧道安全运营的重要保障之一;该互通综合体及其配套弃渣场地,根据各方面综合考虑,位置定于高山峡谷区且需要经过两条泥石流沟。泥石流沟的危险性评价对泸定互通综合体以及弃渣场选址的可行性有至关重要的作用。同时由于目前有大量公路、铁路将要或正在山岭重丘区建设,场地利用受限且地灾发育的问题尖锐。由于开挖土石方量巨大和场地有限,弃土场的选址考虑利用现有泥石流沟。因此弃土场位置的选择与泥石流沟的综合利用也都是这些工程项目至关重要的关键问题。本论文在研究了雅安至康定高速公路设计过程中,根据现场自然地理情况及水文、地质条件,分别分析治理前和治理后泥石流沟对泸定互通综合体及弃土大坝的危险性,并给出合理的工程设计建议。通过本文的研究,希望为今后类似地区公路建设,综合利用泥石流沟进行有关设计提供可行的思路。通过本文研究,取得了以下几点成果:(1)通过选取地形地貌、地质条件、物源条件、植被、气候等泥石流形成的多种因子,采用对五里沟主沟及其支沟进行泥石流危险性评价。通过评判,五里沟主沟泥石流易发程度的量化分值为80分,该沟泥石流的易发程度为轻度易发;五里沟支沟泥石流易发程度的量化分值为72分,该沟泥石流的易发程度为轻度易发。(2)通过野外调查、遥感影像判识等手段,对五里沟进行泥石流沟域分区和启动条件进行分析。分析表明,五里沟及其支沟在有利的地形地貌、物源条件及极端降雨条件下,较易发生泥石流灾害。(3)结合五里沟现场调查资料,参考相关规范、经验参数,计算得出五里沟泥石流主要特征值。五里沟最大泥石流峰值流量为237.599m3/s,泥石流体中大石块冲击力为2302.19k N,五里沟主沟泥石流最大爬高为2.024m。(4)运用类比法,参考相关设计规范,分析五里沟泥石流对桥墩的危险性。计算得出桥墩能承受的最大冲击力为2636k N,大于泥石流体中大石块冲击力。但考虑泥石流夹带的大量石块会对桥墩进行多次的冲击,短时间内可能会对桥墩造成毁灭性的破坏。(5)通过建立弃土大坝的数值模型,考虑暴雨、地震及极端情况(暴雨+地震)工况等因素,运用flac3d软件对弃土大坝进行数值分析和动力响应分析。根据FLAC模拟计算,大坝在泥石流发生并伴随地震工况下最不稳定,易发生整体失稳,对泸定互通及雅康高速公路存在很大危险。(6)通过分析治理后泥石流对大坝危险性,对比工程措施的有效性,对泥石流防治及高速公路的设计提出了进一步的设计建议。
[Abstract]:Luding Intercommunication complex is an important part of traffic conversion service facilities of Ya'an to Kangding Expressway, and is also one of the important guarantees for the safe operation of Erlangshan Super long Tunnel in the later period.According to the comprehensive consideration of all aspects, the location is located in the alpine canyon area and two debris flow gullies are needed.The risk assessment of debris flow gullies plays an important role in the feasibility of Luding interworking complex and site selection.At the same time, because there are a large number of highways, the railway is going to be or is being built in the mountainous and heavy hill area, so the utilization of the site is limited and the problems of the disaster development are acute.Because of the large amount of excavation and the limited site, the site of the dump site is considered to use the existing debris flow ditch.Therefore, the selection of disposal site and the comprehensive utilization of debris flow gullies are also the key problems of these projects.In this paper, during the design of Ya-Kangding Expressway, according to the natural geographical situation, hydrological and geological conditions, the risk of debris flow gully to Luding interworking complex and abandoned dam is analyzed respectively before and after treatment.Reasonable engineering design suggestions are also given.Through the research of this paper, the author hopes to provide feasible ideas for highway construction in similar areas in the future and comprehensive use of debris flow gullies for relevant design.Through the research of this paper, the following results are obtained: 1) through selecting various factors of debris flow formation, such as landform and geomorphology, geological condition, provenance condition, vegetation, climate and so on, the risk of debris flow in the main gully of Wuli gully and its branches is evaluated.According to the evaluation, the quantitative score of debris flow susceptibility in Wuli gully is 80 points, the vulnerability degree of debris flow in this ditch is mild, the quantitative score of debris flow vulnerability in Wuligou branch ditch is 72 points.The susceptibility degree of debris flow in the gully is mildly easy to occur. (2) by means of field investigation and remote sensing image recognition, the zoning and starting conditions of debris flow gully area in Wuli gully are analyzed.The analysis shows that the Wuligou and its branch gullies are prone to debris flow disasters under favorable topographical and geomorphological conditions, provenance conditions and extreme rainfall conditions.The main characteristic values of debris flow in Wuli gully were calculated.The maximum peak flow of debris flow in Wuli ditch is 237.599m3 / s, the impact force of large rock in debris flow body is 2302.19kN, and the maximum climbing height of debris flow in main ditch of Wuligou is 2.024m. 4) the hazard of debris flow in Wuligou to pier is analyzed by analogy method and referring to relevant design specifications.The maximum impact force of pier is 2636kN, which is larger than that of rock mass in debris flow.However, considering a large number of rocks contained in debris flows will impact the pier many times, and may cause devastating damage to the pier in a short time. (5) by establishing a numerical model of the abandoned dam, the rainstorm is considered.The seismic and extreme conditions (rainstorm earthquake) and other factors are used to analyze the dynamic response and numerical value of the abandoned dam by using flac3d software.According to the FLAC simulation calculation, the dam is the most unstable under the condition of debris flow and accompanied by earthquake, which is prone to overall instability. There is a great danger to Luding Intercommunication and Yakang Expressway by analyzing the risk of debris flow to the dam after treatment.Compared with the effectiveness of engineering measures, further design suggestions are put forward for debris flow prevention and highway design.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U418.56;P642.23

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