施工导流明渠多目标优化设计模型

为优化导流明渠设计方案,以明渠底板高程为设计变量,基于施工导截流系统的整体视角,从明渠导流工程成本、施工强度及导截流风险三方面入手,构建施工导流明渠多目标优化设计模型;采用线性加权和法将模型中的子目标函数耦合为单目标函数,运用粒子群算法求解模型。基于某水电工程实例,仿真分析明渠底板高程与导流工程成本、施工强度及导截流风险的关联特性,通过曲线估计拟合其函数关系式。在此基础上实现了对明渠底板高程的优化调整,验证了模型的可行性及有效性。结果表明:提出的优化模型能够实现导流工程成本、施工强度及导截流风险的综合考虑,尤其是考虑施工截流风险对优化结果的影响,能够有效地降低截流风险及风险损失。

基于BN-PERT进度风险分析模型的地铁项目进度风险分析

考虑城市地铁项目建设过程中的风险因素及其相关性和非主导线路对工期的影响,在计划评审技术(PERT)的基础上,建立了一种基于贝叶斯网络(BN)和修正PERT的BN-PERT进度风险分析模型。该模型以进度计划和风险贝叶斯网络为基础,引入乐观系数反映决策者偏好,利用语言变量描述专家等级判断,采用模糊数将语言变量转化为概率值,使用BN的概率推理功能和修正的PERT分析工程进度的期望工期和风险率。通过对某地铁工程的实例分析表明,BN-PERT模型的计算结果较好地反映了工程风险的客观属性及其特征。

考虑上游同步建设条件下沙坪一级水电站初期导流风险分析

针对大渡河流域中同步建设的枕头坝二级水电站和沙坪一级水电站相距较近的特点,基于Monte-Carlo方法进行洪水模拟得到上游堰前水位分布,考虑水库连溃,建立梯级施工导流风险模型。结合贝叶斯原理提出沙坪一级水电站导流风险率计算方法,分析枕头坝二级水电站对沙坪一级水电站施工导流风险的影响。风险计算结果表明,在梯级同步建设环境下,连溃风险较大,提高枕头坝二级水电站的导流标准能有效地降低沙坪一级施工导流风险。

Insurance ratemaking method for risk of construction diversion project

Based on analyzing risk factors of diversion project,synthetic risk rate and engineering insurance period,the frequency and distribution law of loss are researched on the grounds that foundation pit is submerged after diversion project ceases to be effective.And then,the standpoint that these total loss is subject to non-homogeneous compound Poisson processes is put forward.Furthermore,the collective risk model of the total loss about engineering insurance is established on the basis of construction diversion project risk.Ultimately,insurance ratemaking method for construction engineering risk and its mathematical expression are presented,which provides theoretical method for the insurance ratemaking of hydropower engineering to some extent.

The scheme optimization on construction diversion with discharge control feature of upstream operational reservoir

There is a discharge control feature of construction diversion system with the upstream operational reservoir. The risk evaluation model of construction diversion is established by taking into consideration the risk factors of construction diversion system with discharge control feature as well as their composition. And the risk factors include the upstream operational reservoir discharge control, the interval flood and branch flood and the diversion system itself. And then based on analyzing of the conversion relation between risk index and investment index of diversion scheme, the risk control and conversion principals of diversion system are put forward, and the feasible diversion scheme model is built. At last, the risk and economic evaluation and scheme economic feasibility analysis method of diversion scheme are shown by an example of construction diversion scheme optimization with the discharge control condition of upstream hydropower station. The study is valuable for establishment and optimization of construction diversion scheme with upstream reservoir discharge control.

考虑下游库水位变化的街需水电站截流风险分析

根据电站运行要求,确定下游库水位波动范围,并利用DHI Mike 21得到相应的龙口下游水位,采用水力学方法计算不同下游水深对应的龙口最大流速,用截流标准表征截流风险,反映下游库水位变化幅度对截流风险提高或降低的程度,引入工程案例验证了计算模型的可靠性和合理性,计算结果证明了工程方法的可行性。