瞬时溃坝最大流量计算新通式推导及验证

为了计算瞬时溃坝最大流量,基于堰流与波流量相等原理,建立了瞬时溃坝最大流量与堰流关系,理论推导得到同一公式可以计算大坝全溃、横向局部溃坝、垂向局部溃坝及横垂向局部溃坝的瞬时最大流量的新通式,给出了该通式的基本和上限、下限及一般等通式。研究发现:瞬时溃坝流量与溃口堰坎类型有关,可以把瞬时溃坝最大流量、逐渐溃坝洪水或漫坝洪水的计算公式和相应系数统一到不同堰坎类型的堰流量计算中;而这些新通式相应系数的取值是被实验确认和经典著作肯定的,保证了系数取值的可靠和准确。这些新通式容易理解、形式简单、计算简便,参数取值可靠,把溃坝洪水计算的复杂问题转变为处理经典水力学的简单堰流计算。同时通过对比分析,充分论证了一般通式的合理性,并用国内外溃坝实例验证了计算方法和成果较科学、可靠、合理。

Derivation and verification of a new generalized formula set for calculating maximum instantaneous dam breach discharge

In order to calculate the maximum instantaneous dam-break discharge,a relationship between the maximum instantaneous dam-break discharge and the weir flow is established.The theory of equality of wave discharge and weir flow is applied in the study.A new generalized formula set is derived,which includes a basic formula,an up-limit formula,a low-limit formula and a generalized formula,etc.The verification results show that the new generalized formula set is capable of dealing with all types of breaches including whole dam collapse,horizontal partial dam-break,vertical partial dam-break,and both horizontal and vertical partial dam-break.The instantaneous dam-break discharge can be associated with the type of weirs.The new generalized formula set integrates equations for the instantaneous dam-break discharge,and the overtopping or gradually dam-break flood flow,as well as the corresponding coefficients into weir formulas.The values of the coefficients are reliable as they have been validated by available experimental data and classic scientific works.The new generalized formula set is validated with dam-break flow experiments and real-case data,and is proven to be rational and reliable.