常熟市暴雨强度公式编制及应用研究

发布时间：2018-02-13 17:06

本文关键词： 暴雨强度公式优化方法雨水管道压力流　出处：《苏州科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：常熟市原暴雨强度公式于1995年修编,至今18余年,随着常熟市渍涝问题日益凸显,原公式已不符合当前工程设计建设要求,亟需进行修编。另外,由于样本的不规律性,采用传统方法推导的暴雨强度均方差不符合规范要求,导致原暴雨强度公式不满足实际工程要求。本文对暴雨强度公式的推求方法进行了改进,将传统方法的两步最优法改为一步最优法,即以抽样误差和统计误差之和为目标函数,辅以抽样误差和统计误差同时小于误差允许值进行约束,对频率模型参数和暴雨强度公式的参数同时寻优,所得结果可以在约束范围内保证暴雨强度公式的样本误差最小。并采用了多参数暴雨强度公式的方法和二合一优化算法两种方法来进行对比计算,最后推荐采用优化算法的四参数标准暴雨强度公式,作为常熟市暴雨强度公式,并在此基础上对城市排水系统重力流理论和压力排水理论进行分析探讨。论文的主要结论如下:(1)由于实际降雨样本与暴雨公式的规律误差较大,采用传统方法计算结果均方差不符合规范推荐的问题,提出了优化的拟合计算方法,在抽样误差和统计误差这两个步长误差最优的基础上,使样本系统误差最小。(2)通过对比四参数、五参数、六参数的暴雨强度公式,并考虑到各公式在实际工程中的应用情况及规范要求,运用优化拟合算法计算得到2012版常熟市暴雨强度公式。(3)针对压力流状态的雨水管道,本文基于连续性方程和最大雨强公式,提出采用瞬时暴雨强度公式,并取峰值强度计算其设计流量。改进了此种状态下雨水管道的设计现状,是对目前的雨水管道设计计算方法的完善。(4)由于管腔调蓄对于削减雨峰流量的重要作用,重力流状态的工况比压力流状态适应更高强度的降雨,建议在管道设计时采取合理的措施来避免管道处于压力流工况,如控制降低排出口河水位,采用管道浅埋、明沟、平坡管道等方式排水,以提高雨水管道的过水能力。
[Abstract]:The original torrential rain intensity formula of Changshu city was revised in 1995 and has been revised for more than 18 years. With the waterlogging problem in Changshu city becoming increasingly prominent, the original formula does not meet the requirements of current engineering design and construction and needs to be revised. In addition, due to the irregularity of the sample, The RMS derived by the traditional method does not meet the requirements of the specifications, which leads to the failure of the original rainstorm intensity formula to meet the actual engineering requirements. This paper improves the calculation method of the torrential rain intensity formula. In this paper, the two-step optimal method of traditional method is changed into one-step optimal method, that is, the sum of sampling error and statistical error is taken as the objective function, and the sampling error and statistical error are simultaneously less than the allowable value of error. The parameters of frequency model and rainstorm intensity formula are optimized simultaneously. The obtained results can ensure the minimum sample error of the rainstorm intensity formula within the constraint range, and the method of multi-parameter rainstorm intensity formula and the two-in-one optimization algorithm are adopted to carry out the comparative calculation. Finally, the four-parameter standard torrential rain intensity formula of the optimization algorithm is recommended as the torrential rain intensity formula of Changshu city. On this basis, the gravity flow theory and pressure drainage theory of urban drainage system are analyzed and discussed. The main conclusions of this paper are as follows: (1) because of the large error between the actual rainfall sample and the rainstorm formula, The problem of deviation of mean square error (RMS) calculated by the traditional method is not in accordance with the standard recommendation. An optimized fitting method is proposed, which is based on the optimum step error of sampling error and statistical error. The system error of the sample is minimized by comparing the torrential rain intensity formula with four parameters, five parameters and six parameters, and taking into account the application of each formula in practical engineering and the requirements of the specifications. In this paper, based on the continuity equation and maximum rain intensity formula, the instantaneous rainstorm intensity formula is proposed for Rain Water pipeline under pressure flow. The design flow is calculated with peak strength. The present design situation of rain water pipeline in this state is improved, which is the perfection of the current design and calculation method of Rain Water pipeline.) because of the important role of regulating and storing the lumen to reduce the rain peak discharge, The gravity flow condition adapts to the higher intensity rainfall than the pressure flow condition. It is suggested that reasonable measures should be taken to avoid the pipeline in the pressure flow condition, such as controlling and lowering the outlet water level, adopting shallow buried pipe, open ditch, and so on. The flat slope pipeline and other drainage methods to improve the Rain Water pipeline water capacity.
【学位授予单位】：苏州科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU992.02;TV125

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