摘要
坡面泥石流是斜坡地貌演化的重要环节,也是我国山区公路的主要水毁灾害,具有分布广、出现频率高、致灾作用强等特点。从地貌演化观点,将坡面泥石流演化模式分为顶部刮铲演化模式(模式1)、溯源挖掘演化模式(模式2)和局部饱和孕滑演化模式(模式3),其中模式1遵循蠕滑→滑流→刮铲滑流→沉积演化过程,模式2遵循前缘开裂→崩滑→链式崩滑→沉积演化过程,模式3遵循局部饱和→蠕滑→滑流→沉积演化过程;针对坡面泥石流演化模式3,选取前期降雨量120 mm和降雨强度15 mm/(10 min)的试验工况,前期降雨分4次,降1 h,停2 h,强降雨分4次降雨实施,降1 h,停30 min,通过室内模型试验,通过试验过程中土体参数实时监测分析了前期降雨入渗阶段土体中含水量、孔隙水压力的变化规律,强降雨阶段揭示了局部饱和阶段、蠕滑阶段、滑流阶段和沉积阶段随试验过程的变化过程,量化了饱和区、蠕滑区、滑流区、沉积区的面积大小与试验持续时间的关系;初步分析了坡面泥石流演化过程研究的复杂性及研究趋势,尤其应高度重视坡面泥石流演化各阶段的力学机制描述与转换问题研究。
Slope debris flow is the important link of geomorphic evolution for slop,and also is the main water damage disaster of mountainous highway in China.It possesses the characteristics of wide distribution,high frequency appearance,and strongly disaster-caused effect.From the point of geomorphic evolution,evolution model of slope debris flow is divided into top scraping development model （model 1）,digging upward development model （model 2）,and local saturated-triggering development model （model 3）.Model 1 follows the evolution process of creep sliding,sliding-flowing,scraping-sliding,and depositing.Model 2 follows the developing process of cracking in the front,collapsing-sliding,chain collapsing-sliding,depositing.Model 3 follows the developing process of local saturated,creeps sliding,sliding-flowing,depositing stage.Aims to evolution model 3,choose the test condition of 120 mm previous rainfall and 15 mm/（10 min） rainfall intensity.Moreover,rainfall 1 hour duration after 2 hours stopping intervition of one stage,including four stages of previous rainfall,rainfall 1 hour duration after 30 min stopping of rainfall intensity,including four stages.Trough indoor model test,some soil parameters have been measured,analysis the changing characteristics of curves of water content,pore water pressure finely reveal the changing process of local saturated stage,creep sliding stage,sliding-flowing stage,and depositing stage in the test.Quantify the relationship between area size and test duration of saturated region,creep sliding region,sliding-flowing region,and depositing region.It preliminarily analyses the complexity of the study on the evolution process of slope debris flow and research trend.Above all,study on the description of mechanical mechanism and conversion should be paid attention to for each stage of development.Study results have positive meaning in implementing the study on evolution mechanism of slope debris flow and promoting disaster prevention and reduction of slope debris flow.
出处
《山地学报》
CSCD
北大核心
2014年第1期98-104,共7页
Mountain Research
基金
国家自然科学基金项目"坡面泥石流精细演化机制研究"(编号41071017)~~
关键词
地貌学
演化模式
坡面泥石流
室内模型试验
geomorphology
evolution model
slope debris flow
indoor model test
