摘要
采用粗砂加细粒,配置不同细粒含量的土样,在特定边坡坡度、不同降雨强度条件下,分别进行了泥石流室内模型试验。基于不同细粒含量下边坡的破坏过程,分析边坡的宏观位移场、孔压、含水率等,研究不同降雨条件下细粒含量对泥石流形成形态的影响。研究结果表明:不同细粒含量的坡体发生泥石流时宏观破坏形态不同;在50mm/h降雨强度条件下,细粒含量为0%~10%的坡体均能发生分层滑动破坏并形成泥石流;细粒含量大于25%时,坡体破坏形态以坡面冲刷破坏为主,难以形成泥石流;在相同细粒含量下,降雨强度的变化能够显著改变坡体的破坏形态并对是否发生泥石流有重要影响;细粒含量影响坡体渗透系数,是坡体不同破坏形态的主要原因之一。
Under the specific slope gradient and different rainfall intensity,the coarse sand and fine particles are used in indoor model tests to study debris flow with different fine particle content respectively.Based on the failure process of debris flow with different fines content,the macroscopic displacement fields,pore water pressure and water content are measured to study the effects of fines content under different rainfall intensity on slope failure pattern. The results show that the macroscopic failure models of slope are different under different fines content. Under 50 mm/h rainfall intensity for the slope with 0% ~10% fine particle content,the debris flow can occur after the formation of hierarchical sliding. Slope erosion damage will happen when the fine particle content is more than 25% and they are difficult to form debris flow. The variation of rainfall intensity could change slope failure pattern and has significant influence on whether it forms debris flow or not under the same fines content. Fine particle content affects the permeability coefficient of slope and meanwhile is one of main reasons for the different slope failure pattern.
出处
《工程勘察》
2017年第12期1-8,14,共9页
Geotechnical Investigation & Surveying
基金
国家自然科学基金资助项目(51479138)
关键词
泥石流
室内模型试验
细粒含量
降雨强度
破坏形态
debris flow
indoor model test
fines content
rainfall intensity
failure pattern