泥石流堵河条件的研究  

Study on conditions of river-blocking due to debris flow

作　　者：陈春光[1] 姚令侃[1] 刘翠容[1] 杜翠[1] 

机构地区：[1]西南交通大学土木工程学院,四川成都610031

出　　处：《水利学报》2013年第6期648-656,共9页Journal of Hydraulic Engineering

基　　金：国家重点基础研究发展计划(973计划)(2011CB409902)

摘　　要：泥石流堵塞主河是山区河流常发生的灾害之一。本文首先通过室内模型试验,观察到了泥石流堵河的3种形式,即潜坝壅堵、堰塞坝局部阻塞、堰塞坝全堵。根据室内试验得到的堵河过程,建立了交汇区的动力学方程,并结合质点网格(PIC)和标志网格(MAC)算法,提出适用于泥石流与主河水流相互作用的双场耦合模型。该模型主要特点是对混合区不同单元可以用交汇过程中的计算容重表达非牛顿流体的流变参数,还可表达不同单元的泥沙沉积速度。通过模拟计算分析了泥石流堵塞主河的各种主要因素,如速度比,泥石流流变参数、泥石流总量等。在归纳分析试验结果及模拟计算结果的基础上,阐述了采用动量比判定泥石流堵河临界条件的理由,并提出了采用动量比乘以泥石流冲入河道无量纲总量作为堵河的判定综合因子。River-blocking due to debris flow is one of the disaster-phenomena happened frequently in the mountain rivers. First, three forms of the debris-flow blocked river, which are the congestion by de- bris-flow submerged, the partial blockage and complete blockage, have been observed through tests in the lab. Meanwhile, it is proved that the total amount of debris-flow is an important factor in the river-block- ing events. Based on the process of river-blocking obtained by the laboratory tests, dynamic equations for fluid in the confluence area are established. Combining with the Particle-In-Cell （PIC） and Marker and Cell （MAC） method, a coupling model is presented for interaction between debris flow and the main river. The main characteristic of the model is that the rheologieal parameters and sediment settling velocity in the calculation unit of confluence may be expressed with the aid of the specific weight of mixed fluid. The ma- jor factors of debris-flow blocking the main river, such as velocity ratio of debris flow and flow in the main river, rheological parameters of debris flow, the total amount of debris flow etc., are analyzed through numerical simulation. On the basis of inductive analysis of experiment results and simulation re- suits, the reasons for using the momentum ratio as the critical condition determining the event of riv- er-blocking is explained, and a discriminate index for the river blockage is proposed, which is the product of momentum ratio and volume ratio of debris flow in the river.

关 键 词：泥石流 堵河条件 试验研究 数值模拟 

分 类 号：P642.23[天文地球—工程地质学]