| 降雨入渗影响下边坡中的非饱和渗流特性 |
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| 引用本文： | 许旭堂,简文彬,吴能森,徐祥,刘景良.降雨入渗影响下边坡中的非饱和渗流特性[J].地球科学,2018,43(3):922-932. |
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| 作者姓名： | 许旭堂 简文彬 吴能森 徐祥 刘景良 |
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| 作者单位： | 1.福建农林大学交通与土木工程学院, 福建福州 350002 |
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| 基金项目： | 福建省教育厅中青年教师教育科研项目JAT170173交通土建师资队伍博士化国际化工程项目61201405105福建省自然科学基金项目2015J01164国家自然科学基金项目41702288 |
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| 摘 要： | 为了分析降雨入渗影响下非饱和土坡渗流特性，利用自制降雨模拟系统和实时监测系统，对降雨诱发非饱和土坡失稳过程进行全方位、多参量的实时监测，研究不同降雨条件下，不同坡度、不同压实度边坡坡体不同位置雨水入渗率和湿润峰的实变规律.结果表明:降雨入渗条件下，陡坡和高压实度土体不利于雨水入渗，而缓坡和低密实度土体入渗率变化快；实际土体吸力和含水量实时变化规律不同步，提出试验湿润峰概念，含水率（吸力）湿润峰点可按含水率（吸力）实时曲线的过渡区和雨后残余含水率（吸力）的线性交叉点确定；考虑单向吸湿或脱湿路径下土体含水率和吸力具有唯一对应关系，含水率湿润峰点与吸力湿润峰点的绝对值时差即为形成湿润峰所需时间；对比湿润峰实测值与Lumb半经验值散点分布规律，基于Lumb湿润峰深度计算公式提出非线性修正表达式.
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| 关 键 词： | 边坡 非饱和渗流 降雨入渗 湿润峰 实变规律 修正Lumb表达式 |
| 收稿时间： | 2017-11-29 |
Unsaturated Seepage Characteristics of Slope under Rainfall Infiltration |
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| Abstract: | In order to analyze unsaturated seepage characteristics of slope under rainfall infiltration, a rainfall simulation system and real-time monitoring system were employed for conducting model tests to simulate the rainfall-induced unsaturated soil slope failure process in this study. The real-time response of infiltration rate and wetting front of soil slope with different slope angles, different compaction degrees and different locations under different rainfall conditions were recorded and analyzed. Results show that steep slope and high compaction degree soil are not conducive to rainfall infiltration, while gentle slope and low compaction degree soil have a quick change of infiltration rate; the concept of test wetting front is proposed due to the real-time law of actual soil suction and water content under rainfall conditions are not synchronized, and the water content (suction) wetting front point can be determined by a linear intersection of water content (suction) real-time curve transition zone and residual water content (suction) after rainfall; considering water content and soil suction have the only corresponding relationship under unidirectional wetting and drying path, the time needed for wetting front formation can be seen as the absolute value of time differences between water content and suction wetting front point. Based on the Lumb formula of wetting front depth, the nonlinear correction expression is proposed subsequently by comparing the scatter distribution of wetting front measured and semi-empirical values. |
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