高寒、强震山区沟谷灾害链判据与线路工程减灾对策

发布时间：2018-04-03 12:16

本文选题：高寒强震山区　切入点：沟谷灾害链　出处：《西南交通大学》2015年博士论文

【摘要】：随着极端天气和地质事件增多,我国泥石流堵塞大河事件频发；此外,在海洋性冰川覆盖区,冰川泥石流堵河和冰碛堰塞湖溃决一直是高发事件。严重影响着人们的生命财产安全,制约着经济的发展,防灾减灾问题提上日程。论文选取汶川地震灾区岷江流域和藏东南帕隆藏布流域两个为研究区。首先,以汶川地震后岷江流域石流堵塞大河事件为对象,采用现场调查、室内水槽实验和理论分析相结合的手段,研究泥石流堵塞大河判据,并为下一步帕隆藏布流域国道318沿线泥石流堵河危险性分析奠定基础。其次,结合泥石流堵河壅水高度,利用帕隆藏布流域冰碛台地连片分布的特点,进行初步布线探究。最后,通过大型振动台试验,初步研究地震涌浪与冰湖溃决的关系。本文研究结果如下：(1)依据Takahashi泥石流在坡度变化沟道中的运动公式,考虑泥石流进入主河后受主河河床阻力和河水顶托阻力,给出泥石流在主河中运移的动力学方程,推导出泥石流在主河中的运移距离计算公式。通过分析野外调查的泥石流物质总量与堵塞系数数据,给出泥石流与堵塞系数的公式为y=76x-30。同时对室内水槽实验得出泥石流物质总量与堵塞系数的数据与野外调查的数据进行归一化处理分析,验证了现场调查数据拟合的计算公式的斜率具有普适性。因此,泥石流物质总量与阻塞系数可用一般式y=76x+b表示(其中b值可根据具体的流域中的一条沟的数据得出)。该公式可用以快速估计该流域其他泥石流沟堵河的泥石流物质总量。泥石流的物质组构决定了泥石流坝体在大河中能否稳定存在,利用渗流理论推导出泥石流在主河中形成稳定坝体的条件是泥石流物质中大颗粒所占比例大于50%,通过对典型泥石流沟-高家沟(映秀-汶川段)进行现场调查,并对采集的样品进行室内大直剪实验,验证了泥石流在大河中形成稳定坝体的条件是泥石流物质中的大颗粒含量占50%以上。(2)通过对帕隆藏布流域的泥石流沟现场普查,典型泥石流沟的详查,结合收集到的历史资料分析,给出帕隆藏布流域按不同水动力条件的泥石流沟分布图、泥石流堵河严重性图。并结合主河的河谷形态及泥石流沟堵河的严重程度对帕隆藏布流域泥石流堵河进行危险性评估,给出泥石流堵河危险性评估图。(3)考虑沟谷灾害链导致干流水位大幅度提高,在峡谷段大段落采用高线位方案,以规避干流中发生的超常水害。通过现场调查及帕隆藏布流域航卫片的分析,绘制帕隆藏布流域山麓地带地貌分布图,对现场采集的冰碛物进行室内大直剪实验得出冰碛物具有良好的工程性质,可作为路基填料。通过分析冰碛台地的高度并结合历史上泥石流一次性堵河的案例,得出冰碛台地满足线位高于泥石流一次堵河的洪水位高度的要求,并利用冰碛台地进行了铁路线路初步设计。(4)通过大型振动台水箱模型实验模拟地震造成的地震水波。以卧龙波(2008.5.12汶川地震,主频1Hz高频)、Mexicali波(主频1Hz低频)、通麦波(人工合成波,高频)、白噪声(测振动台模型的自振频率)为扰动源,以初始水深为35cm为初始条件开展对比实验。利用去趋势互相关分析方法对游泳池数据、实验数据和现场数据进行对比分析,验证振动台实验的可行性。对振动台水箱模型实验数据进行分析建立了地震峰值加速度与地震涌浪峰值的模型。以帕隆藏布流域米堆冰湖为案例,对比分析冰碛湖溃决的临界水文条件,利用地震峰值加速度与地震涌浪模型,对冰湖溃决进行危险性判识。
[Abstract]:With the increase of extreme weather and geological events, China River debris flow events occurred frequently; in addition, in the area covered by marine glaciers, glacial debris flow blocking the river and moraine dammed lake outburst has been the high incidence of events. A serious impact on people's life and property safety, restricting economic development, disaster prevention and mitigation issues on the agenda. The paper selected Wenchuan earthquake the disaster area of Minjiang River Basin and Southeast Tibet two Palongzangbu basin as the study area. First of all, in Wenchuan after the earthquake of Minjiang River stone river flow blocking events as the object, through field investigation, indoor flume experiment and theoretical analysis method of combining research of debris flow, river and river as the criterion, risk analysis to lay the foundation for the next block step Palongzangbu Basin National Highway 318 along the debris flow. Secondly, combined with the debris flow blocking the river backwater, the Palongzangbu basin moraine platform of regional distribution characteristics, the initial Step routing inquiry. Finally, through the shaking table test, a preliminary study on the relationship between seismic surge wave and glacial lake outburst. The results of this study are as follows: (1) based on the Takahashi equation of motion of debris flow on the slope change in the channel, consider the debris flow into the main River after the river river backwater acceptor resistance and resistance, dynamic equation of debris flow movement in the main river, the migration distance calculation formula deduced in the main river in debris flow. Through the analysis of the total debris flow field investigation and blockage coefficient data, given the debris flow and the blockage coefficient formula for y= 76x-30. at the same time that the total amount of debris flow and blockage coefficient on the flume experiment data and field survey data were normalized to verify the calculation formula of slope analysis, field investigation data fitting is universal. Therefore, the total amount of debris flow and congestion line number Represented by the general formula y=76x+b (wherein B value can be obtained according to a channel specific watershed in the data). The formula can be used to quickly estimate the other basin debris flow blocking the river. The total amount of debris flow material group debris flow determines the debris flow dam construction can stable exist in the river, based on percolation theory is deduced the formation of debris flow in the main river dam stability conditions are large granular debris flow in the proportion of more than 50%, according to the typical debris flow ditch gaojiagou (Yingxiu Wenchuan section) were surveyed, and the collection of samples for indoor direct shear test, verified the formation of debris flow dam in the river in stable conditions is the large particle content in debris flow accounted for more than 50%. (2) through the field survey of debris flow of Palongzangbu basin, typical debris flow investigation, combined with the collected historical data analysis, are given The Palongzangbu river basin according to the distribution of debris flow in different hydrodynamic conditions, the debris flow blocking the river. The severity of severity and combined with the valley morphology and debris flow blocking the river on the main river Palongzangbu river blocking Valley debris flow risk assessment, risk assessment of debris flow are blocking the river. (3) to mainstream the water level increased greatly considering gully disaster chain, using a wire in the gorge scheme to avoid big paragraph, the main stream water. Through the investigation and analysis of abnormal Palongzangbu basin site satellite images, drawing the Palongzangbu basin Piedmont topographicmaps, the moraine collected indoor large direct shear experiment results show that the moraine Engineering property is good, can be used as roadbed filler. Through the analysis of platform height and moraine combined with the history of debris flow blocking the river disposable case, draw the line in a high platform to meet the moraine In a debris flow blocking the river flood height requirement, and the preliminary design of the railway line. The moraine platform (4) by large-scale shaking table model to simulate seismic wave tank caused by the earthquake. In Wolong (2008.5.12 Wenchuan earthquake wave frequency 1Hz high frequency Mexicali wave (1Hz), frequency of low frequency), Tangmai wave (synthetic wave, high frequency), white noise (vibration frequency vibration table model) as the disturbance source, the initial water depth of 35cm to carry out comparative experimental initial conditions. Using detrended cross correlation analysis method of data pool, experimental data and field data were analyzed to verify the feasibility of shaking table experiment the experiment data of tank model is established through the analysis of the seismic peak acceleration and peak seismic surge wave model for the shaking table. The Palongzangbu basin rice pile ice lake as an example, analyzed the critical hydrological condition of moraine dammed lake outburst, The peak acceleration of earthquake and earthquake wave model of glacial lake outburst risk identification.

【学位授予单位】：西南交通大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：P642.23

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