粘性泥石流坝后回淤的实验研究
文献类型：学位论文
| 作者 | 吴鑫 |
| 学位类别 | 硕士 |
| 答辩日期 | 2013 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 马东涛 |
| 关键词 | 粘性泥石流 拦挡坝 重度 沟床纵坡 回淤比降 |
| 其他题名 | Experiment on Back Siltation of Viscous Debris Flow behind Gravity Check-dam |
| 学位专业 | 建筑与土木工程 |
| 中文摘要 | 泥石流拦挡坝的坝后回淤比降是拦挡坝工程设计中的一个重要参数，其直接关系到拦挡坝坝高、坝间距、拦砂库容的确定和减灾效益发挥、工程使用寿命等。回淤比降受沟床纵比降和泥石流重度、流速、流量、级配等多种因素综合影响，其中与沟床纵比降和重度关系较为密切。本次实验中选取粘性泥石流，开展了8组沟床纵比降(9.5%、12.1%、14.4%、16.7%、18.9%、21.3%、23.8%、26.2%)和6组重度(17kN/m3、18 kN/m3、19 kN/m3、20 kN/m3、21 kN/m3、22 kN/m3)条件下的坝后回淤的模拟实验，研究了沟槽纵比降及重度对粘性泥石流坝后回淤比降的影响，分析回淤比降比与沟槽纵比降及重度的关系，以及坝后回淤形态特征，结合实际工程观测和稀性泥石流坝后回淤实验，对实验结果进行了分析。 实验发现： （1）沟床纵比降是影响坝后回淤的主要因素，其次为重度。 （2）回淤比降随沟槽纵比降的增大而增大，二者呈线性正相关；回淤比降随重度的增大，总体呈缓慢增大的趋势，二者为二次函数关系。 （3）回淤比降比K介于0.76到0.85之间，其与重度和沟槽比降均呈2次函数关系。沟槽纵坡在14.4%~16.7%和重度19~20kN/m3时，回淤比降比分别达到最小值。 （4）在坝后距坝顶较近位置存在一个坝后回淤最高点，回淤最高点出现在距坝顶2~4倍坝高距离位置处。 （5）回淤最高点距坝顶的距离与重度及沟槽纵比降之间均存在二次函数关系，其随着重度的增加，先增后减，相关性好；而随着沟床纵坡的增加，先增加，后减小，最后再增加，总体呈现增大的趋势，但关系较为复杂。 （6）通过与云南小江流域大凹子沟、大桥河浑水沟泥石流拦挡工程实际观测对比分析发现，在重度和沟床纵比降相似的条件下，实验结果与实际观测值较为接近。 |
| 英文摘要 | The gradient of back siltation is an important parameter for designing gravity check-dam of debris flow, which is not only influencing the judgment of the height, the distance between dams, the deposit capacity of debris flow reservoir, but also the mitigation benefit and engineering life of check–dams. The gradient of back siltation is affected by the gradient of gully bed, the density, flow velocity and discharge , and grain compositions of debris flow et al factors, among which the gradient of gully bed and the density debris flow are most important than others. By using the viscous debris flow in the laboratory, we carry out simulation experiments under 8 groups of the gradient of gully bed(9.5%、12.1%、14.4%、16.7%、18.9%、21.3%、23.8% and 26.2%) and 6 groups of debris flow densities(17KN/m3、18 KN/m3、19 KN/m3、20 KN/m3、21 KN/m3 and 22 KN/m3). After the experiment finished, the influences of gradient of gully bed and the density of debris flow to siltation back check-dam, and the relationship between them are studied and analyzed. The following results are achieved through the experiment: (1) The gradient of gully bed is the more important factor which affects the back siltation of check-dam in compared with the density of viscous debris flow. (2) The gradient of back siltation is increasing with the increase of the gradient of gully bed, and there is a linear relationship between them. The gradient of back siltation is increased slowly with the increase of density of debris flow, they have a quadratic relationship each other. (3)The gradient ratio parameter value K is between 0.76 and 0.85, which has a quadratic relationship with the density of debris flow and the gradient of gully bed. K reaches the minimum value while the gradient of gully bed is 14.4%~16.7% or the density of debris flow is 19 N/m3~20KN/m3. (4) There is a highest point behind the dam along siltation slope, the distance of the highest point to check-dam site is about 2~4 times of the height of the check-dam. (5) The distance between the highest point and the dam has a quadratic relationship with density of the debris flow and gradient of the gully bed. With increasing of the debris flow density, the distance increase at first and decrease later. With increasing of the gradient of the gully bed, the distance increase at first, then decrease and increase at last. (6) In comparing to Da Aozi and Da Qiaohe debris flow gully in Xiaojiang River Bain of Yunnan, it is found that the consequence of experiment is close to the practical values of measurements while the density of debris flow and gradient of the gully bed is at the same condition. |
| 语种 | 中文 |
| 公开日期 | 2014-08-26 |
| 源URL | [http://ir.imde.ac.cn/handle/131551/7139]  |
| 专题 | 成都山地灾害与环境研究所_山地灾害与地表过程重点实验室 |
| 推荐引用方式 GB/T 7714 | 吴鑫. 粘性泥石流坝后回淤的实验研究[D]. 北京. 中国科学院研究生院. 2013. |
入库方式： OAI收割
来源：成都山地灾害与环境研究所
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