泥石流冲击力的时空分布特征
Spatio-temporal Distribution of the Impact Force of Debris Flow
作者:刘道川(中国科学院 山地灾害与地表过程重点实验室, 四川 成都 610041;中国科学院 水利部成都山地灾害与环境研究所, 四川 成都 610041;中国科学院大学, 北京 100049);游勇(中国科学院 山地灾害与地表过程重点实验室, 四川 成都 610041;中国科学院 水利部成都山地灾害与环境研究所, 四川 成都 610041);杜杰(九寨沟风景名胜区管理局, 四川 九寨沟 623402);柳金峰(中国科学院 山地灾害与地表过程重点实验室, 四川 成都 610041;中国科学院 水利部成都山地灾害与环境研究所, 四川 成都 610041);关辉(西南科技大学 环境与资源学院, 四川 绵阳 621010);刘洋(中国科学院 山地灾害与地表过程重点实验室, 四川 成都 610041;中国科学院 水利部成都山地灾害与环境研究所, 四川 成都 610041;中国科学院大学, 北京 100049)
Author:LIU Daochuan(Key Lab. of Mountain Hazards and Earth Surface Process, Chinese Academy of Sci., Chengdu 610041, China;Inst. of Mountain Hazards and Environment, Chinese Academy of Sci., Chengdu 610041, China;Univ. of Chinese Academy of Sci., Beijing 100049, China);YOU Yong(Key Lab. of Mountain Hazards and Earth Surface Process, Chinese Academy of Sci., Chengdu 610041, China;Inst. of Mountain Hazards and Environment, Chinese Academy of Sci., Chengdu 610041, China);DU Jie(Authority of Jiuzhaigou Valley Scenic and Historic Interest Area, Jiuzhai 623402, China);LIU Jinfeng(Key Lab. of Mountain Hazards and Earth Surface Process, Chinese Academy of Sci., Chengdu 610041, China;Inst. of Mountain Hazards and Environment, Chinese Academy of Sci., Chengdu 610041, China);GUAN Hui(School of Resorces and Environment, Southwest Univ. of Sci. and Technol., Mianyang 621010, China);LIU Yang(Key Lab. of Mountain Hazards and Earth Surface Process, Chinese Academy of Sci., Chengdu 610041, China;Inst. of Mountain Hazards and Environment, Chinese Academy of Sci., Chengdu 610041, China;Univ. of Chinese Academy of Sci., Beijing 100049, China)
收稿日期:2018-09-20 年卷(期)页码:2019,51(3):17-25
期刊名称:工程科学与技术
Journal Name:Advanced Engineering Sciences
关键字:泥石流;冲击力;时空分布;刚性坝体
Key words:debris flow;impact force;spatio-temporal distribution;rigid barrier
基金项目:中国科学院“西部之光”人才培养引进计划和四川省委组织部“西部之光人才专项”项目;国家自然科学基金项目(41772343);中国科学院科技服务网络计划项目(KFJ-STS-ZDTP-015)
中文摘要
传统的泥石流冲击力计算方法仅仅考虑泥石流作用于刚性拦挡坝时的瞬间冲击过程,并没有考虑泥石流与坝体相作用时,冲起部分对坝体的影响。实际上,当泥石流与坝体相作用而冲起爬高时,所受泥石流冲击力的空间分布决定了其结构的稳定性。本文开展了系列泥石流冲击实验,并利用Tactilus内置式压力分布测量传感器测量冲击力数据,以此来探究不同密度泥石流作用于坝体时冲击力的时空分布特性。实验结果表明,低密度泥石流冲起爬高时,在坝体范围内冲击力时程变化的波动更为剧烈,持续时间也更长。低密度泥石流与坝体作用时,最大冲击力主要来自于流体中颗粒与坝体的撞击作用,并存在于整个冲击过程,而高密度泥石流与坝体作用时,最大冲击力出现在与坝体刚接触的时候,这主要是由于不同密度下流体内部颗粒间作用力变化引起的。当密度较低时,泥石流冲起部分的冲击力的纵向衰减模式为对数函数形式;当密度较大时,其衰减模式为线性函数形式。泥石流冲击力的横向分布波动并不大,基本可以看成是等值分布。为便于计算,泥石流冲击力的纵向分布可以简化为三角形分布。对坝趾处来讲,考虑泥石流冲起时,所受弯矩为不考虑流体冲起时的2~3倍。
英文摘要
The stability of a rigid barrier is determined by the spatio-temporal distribution of the impact of debris flow when the debris flow runs up. However, current approaches used to estimate the debris flow impact have not considered the impact load produced by running up flow. In order to explore the spatio-temporal distribution of debris flow impact, a series of debris flow impact experiments are carried out and a contact surface pressure gauge sensor (called Tactilus®, is produced by Sensor Products LLC) was used to record the evolution of the impact force at the barrier. The experiments result showed that the history of maximum impact force in the space of low density debris flow fluctuated more drastically with a relative long time. In addition, the longitudinal attenuation of the impact force was the logarithmic function for the low density debris flow, while the high density debris flow with linear attenuation. These attenuation modes with different density were fundamentally governed by the grain-fluid interaction. On the other hand, the horizontal distribution of debris flow impact force can be regarded as the equivalent distribution. In order to simplify the engineering design, the longitudinal distribution of debris flow impact can be generalized to triangular distribution, from which a new impact model considering the effect of running up was proposed.
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