【作者】 王珂；

【导师】 张勤；

【作者基本信息】 重庆大学 ， 市政工程， 2007， 硕士

【摘要】 随着近年来我国经济和社会的快速发展,建筑屋面的造型千姿百态丰富多彩,各种大面积的场馆、现代工业厂房在全国各地大量兴建,这些建筑往往气势宏伟、美观实用,但随之也带来了大或超大屋面雨水排水系统设计的问题。此前,我国的屋面排水系统按重力流设计,但是,重力流雨水排水系统受其水力特性的限制,已经不能适应这些工程的需要。近些年在欧洲发展起来了新兴的压力流(虹吸式)屋面雨水排水系统。本文通过对重力流雨水排水系统和压力流(虹吸式)屋面雨水排水系统在技术和经济方面的比较,论证了压力流(虹吸式)屋面雨水排水系统对于超大型、大型和中小型建筑屋面的优越性。压力流(虹吸式)屋面雨水排水系统作为一种新型的雨水排放系统,在该系统的水力工况、降雨的设计重现期及适用的计算公式等问题上仍然争议较大,本文就其中一些热点问题进行了探讨。压力流(虹吸式)雨水排水系统的关键之一是精确地进行水力计算,水力计算的目的是充分利用系统提供的可利用水头,减小管径,降低造价,并保证系统安全、可靠、正常地工作。本文论述了压力流(虹吸式)屋面雨水排水系统的工作原理和水力计算方法,并用C++语言编制了计算机程序,使压力流(虹吸式)屋面雨水排水系统的设计计算实现了自动化,大大减少了计算工作量,提高了计算精度,并使该系统能够更可靠地运行。对于压力流(虹吸式)雨水系统,经济合理地设计雨水管道,使之具有合理的和最佳的排水能力,最大限度地及时排除雨水,又不使建设规模超过实际需求,合理而经济地进行设计具有重要的意义和价值。在对雨水管道进行优化计算时,最终的优化计算结果是通过寻求费用最低而得出来的,即最终决策与费用函数密切相关。本文通过最小二乘法原理将单位长度管段的造价Cg,i拟合为函数形式,从而求出了对雨水管道进行优化的目标函数。但是,在优化设计中,必须根据实际设计要求,对设计变量的取值加以种种的限制,一般表达为设计变量的不等式约束函数或等式约束函数。为了适应目标函数和约束条件的非线性特征,本文建立了非线性规划模型。然后,用罚函数法构造出带参数的辅助函数,将约束问题转化为求解无约束的最优化问题,从而得到最优的管径组合。更多还原

【Abstract】 With the development of the national economy and society in recent years, building′s roofs differ in thousands of ways and become rich and colorful, there are various big area roof exhibition hall and modern industrial workshop being constructed in each place, these constructions are grandiose and artistic practical generally, but has also brought the problems in design of big area roof rainwater drainage system along with it. Design of roof rainwater drainage system in our country according to gravitational fluid formerly, but gravitational rainwater drainage system is limited by its hydraulic characteristic, already could not meet the demands of these projects. Newly emerging siphonic roof rainwater drainage system has been developed in Europe. This paper demonstrates advantages of siphonic roof rainwater drainage system for dium- and large-scale roofs by comparison on gravitational rainwater drainage system and siphonic rainwater drainage system in technical and economical aspects.As a new-style rainwater drainage system, siphonic roof rainwater drainage system has some disputable issues such as hydraulic operating mode, recurrence period of design and suitable calculation formulae, so this paper will discuss these issues. One of the keys of siphonic rainwater drainage system is hydraulics calculation′s accuracy, the goal of hydraulics calculation is taking full advantage of hydraulic head that system offers, minishing pipe′s diameter, reducing costs and ensuring system working safely, reliably and normally. This paper exposits the work principle and hydraulics calculation method of siphonic roof rainwater drainage system, and uses the C++ language to establish the calculator procedure, which makes hydraulics calculation of siphonic rainwater drainage system realize automation, allays the workload greatly, improves hydraulics calculation′s accuracy and makes the system work more stablely.Siphonic rainwater drainage system is a new-style rainwater drainage system, it is very significant to design rainwater pipes economically and rationally, which makes the system have optimal capability of drainage, drain furthest in time but not cause the construction scale to surpass the actual demand. When carries on optimal calculation of the rainwater pipeline, the final optimization computed result is resolved through seeking the costs to be lowest, namely final decision-making and expense function are closely related. This paper studies the curve-fitting of the unit length of pipe cost Cg, i, and extracts objective function accordingly that optimizes the rainwater pipeline. But, in optimal design, we must according to the actual demand and give some restrictions on design parameter, which is expressed as inequality constraint function or equality constraint function of design variable. In order to adapt non-linear characteristic of objective function and the constraint condition, this paper has established the nonlinear programming model. Then, this paper establish accessorial function by penalty function method to turn constraint problem into nonrestraint problem, obtain optimal pipe′s diameter combination accordingly.更多还原