恒定渗流作用泥石流碎屑物质起动判别模型研究

Recognition model on triggering debris flow under constant seepage condition

恒定渗流条件是泥石流碎屑物质起动的主要水动力条件之一,目前鲜有学者对其起动判别模型和坡体内水力学参数变化规律进行研究。初步选取结构简单的碎屑物质作为地质模型进行理论分析,建立起动判别模型,借助模型试验对坡体内水力学参数的变化规律进行探究,同时对判别模型进行验证,并与其他模型进行对比分析。结果表明,恒定渗流过程对碎屑物质起动的作用力主要包括渗透力及渗流冲刷力;渗流速度随底床坡度、入水流量的增大而增大,但随入水流量增加的幅度较小;平行于水流方向的总水头损失随底床坡度的增大呈先减小后增大趋势,随入水流量增大而增大;稳定系数与底床坡度间呈幂函数关系,关系系数因判别模型不同而有所差异;与其他模型相比,模型经严格推导,满足量纲分析和试验验证要求,精度更高。

Constant seepage conditions are one of the main hydrodynamic conditions for triggering the debris flow.However,few scholars have studied the triggering discriminant model and the variation of hydraulic parameters in the slope.In this paper,a simple geological structure consisting of the debris is selected for theoretical analysis,and the triggering discriminant model of debris flow is established.The variation of hydraulic parameters in the slope is studied by means of the model test.The discriminant model is verified and compared with other models.The results show that both the seepage force and the seepage scouring force play an important role in controlling the movement of debris during the constant seepage process.The seepage velocity increases with the increase of bed slope and inlet water flow rate,but the variation degree is smaller for the latter case.The total water head loss parallel to the water flow direction decreases at first and then increases with the increase of the bed slope,and it has a positive correlation with inlet water flow rate.The stability coefficient and the bed slope show a power function relationship.The correlation coefficient differs depending on different discriminant models.Compared with other models,the discrimination model presented in this paper is strictly deduced to meet the requirements of dimensional analysis and experimental verification,and it has a much higher accuracy.