中文摘要：

施工导流系统风险分析采用Monte-Carlo计算机仿真方法，改变了传统导流标准设计只考虑单一水文不确定性因素及数学模型中水力参数为定值的限制．而基于多元不确定性因素的仿真，由于水文和水力参数的不确定性，使仿真计算的堰前水位具有不确定性．为此，建立了施工导流仿真运算数学模型，采用计算机仿真方法模拟系统运行过程，求解堰前水位，应用中心极限定理确定仿真最小运行次数，通过数据统计分析，描绘出堰前水位的经验累计曲线和概率分布曲线．定义系统在设计挡水位失效的概率来描述施工导流系统的风险率，根据概率分布曲线确定现行导流标准下系统的风险率，为施工导流决策提供技术支持．

英文摘要：

As Monte-Carlo computer simulation method is applied to system risk analysis of construction diversion, important changes are made in the limitation of conventional methods which only consider single hydrological uncertainty and assume hydraulic parameters to be fixed values. Based on multiple uncertain factors including hydrological and hydraulic uncertainties, the simulation makes upstream water level uncertain. For this reason, upstream water level is calculated through establishing mathematical model which can simulate system operation during construction diversion. The minimum running times in the simulation are ascertained by using central limit theorem, and then the experiential accumulative curve and probability distribution curve of the upstream water level are obtained by analyzing the statistical data. Finally the system failure probability at the designed water level is defined to reflect risk probability, risk probability under current criteria of river diversion port for construction diversion decision. and according to the probability distribution curve, the is determined. All these will provide technological sup port for construction diversion decision,