摘要
泥质砂岩残积土作为一种结构性很强的特殊土,具有崩解性强、抗冲蚀性差以及扰动性极大的特点,对工程建设有较大影响。为了探究泥质砂岩残积土边坡降雨冲刷机理,设计了边坡降雨冲刷试验,通过现场三维激光扫描技术测试分析了其表面冲刷效应;利用高密度电法进一步明确了泥质砂岩残积土边坡的入渗特性、表面冲刷演化机制及冲刷破坏机理。结果表明:冲刷试验的最初阶段,降水入渗强且主要向坡脚处运移,坡表未形成明显的细沟;冲刷试验中期,坡脚处土体最先达到饱和而形成坡面径流,细沟贯通扩大形成小规模冲槽以及片蚀区;冲刷试验后期,坡面中部和坡脚处土体冲蚀严重,坡脚处的冲槽向上部延伸,片蚀区扩大,导致表层土体结构发生变化,渗透性差异明显;泥质砂岩残积土坡体降雨冲刷主要划分为表层溅蚀、下层潜蚀和细沟贯通3个阶段,坡面土体流失主要发生在最后一个阶段,细沟率达到最高值16.9%,细沟贯通率也高达0.74。研究结果可以为深入探讨泥质砂岩残积土边坡冲蚀防护和研究冲蚀防护机理提供基础资料。
As a special soil with a strong structure,argillaceous sandstone residual soil has the characteristics of strong disintegration,poor erosion resistance and great disturbance,it has great influence on the engineering construction.To explore the mechanism of rainfall erosion of argillaceous sandstone residual soil slopes,a slope rainfall erosion test is designed.The surface erosion effect is analysed by 3D laser scanning technology on site.The infiltration characteristics,surface brush evolution mechanism and erosion failure mechanism of argillaceous sandstone residual soil slopes are further clarified by using a high-density electrical method.The results show that in the initial stage of the experiment,the precipitation was highly permeable and mainly migrated to the foot of the slope,and no obvious rills were formed on the surface of the slope.In the middle period of the erosion test,the soil at the foot of the slope reached saturation first,and slope runoff was formed,and the rill expanded to form small-scale erosion chutes and chip erosion areas.In the later stage of the test,the soil erosion in the middle of the slope and at the foot of the slope was serious.The upwards part of the channel at the foot of the slope extended,and the erosion area expanded,which led to the structural change in the surface soil,and the permeability difference was obvious.The rainfall erosion of argillaceous sandstone residual soil slope was mainly divided into three parts.The soil loss of slope mainly occurred in the last stage,with a maximum rill rate of 16.9%and gully connectivity of up to 0.74.
作者
李继兴
严松
杨春健
方跃光
Li Jixing;Yan Song;Yang Chunjian;Fang Yueguang(Zhaotong Yizhao Expressway Investment and Development Limited Company,Zhaotong Yunnan,657000,China;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China;University of Chinese Academy of Sciences,Beijing 100049,China;Zhaotong Yizhao Expressway Project Headquarters,Zhaotong Yunnan 657000,China)
出处
《地质科技通报》
CAS
CSCD
北大核心
2022年第2期26-33,共8页
Bulletin of Geological Science and Technology
基金
云南省交通厅科教项目“基于原位测试关键技术的山区高速公路高边坡风险评价体系与防治措施研究”([2020]74号)。
关键词
泥质砂岩残积土
边坡
降雨
冲刷
入渗性质
三维激光扫描
高密度电法
argillaceous sandstone residual soil
slope
rainfall
erosion
infiltration property
3D laser scanning
high density electrical method
