降雨径流系数影响因素的试验研究

发布时间：2018-02-16 02:59

本文关键词： 径流系数坡度降雨量雨峰位置下垫面　出处：《湖南大学》2014年硕士论文　论文类型：学位论文

【摘要】：城市化进程的加快，导致城市硬化路面的比例逐年增加，再加上近年来极端天气频发，城市内涝的情况时常发生。径流系数是雨水管网设计时使用的重要参数。而我国目前使用的设计规范中的径流系数，是按下垫面种类取的经验值。其值未考虑下垫面的坡度、各地的实际地理环境情况，取值与实际存在一定的偏差。因此，有必要结合当地的实际情况，研究坡度、土壤等因素对雨水径流系数的影响。本文分析了长沙市的降雨特点，确定了试验中模拟降雨的各项参数。选择长沙市的典型土壤红壤作为绿地的土壤下垫面，以3°、7°、13°为下垫面坡度，铺砖路面（不透水砖）、混凝土路面等容易造成城市内涝的路面材质作为下垫面种类。共进行了46场模拟降雨试验，据此分析了降雨量、坡度、降雨雨峰的位置、下垫面材料这四个因素对雨水径流系数的影响。径流系数与降雨量呈线性关系，其值随着降雨量的增加而增加。降雨量越大，径流产生的时间越短，两者呈指数关系。坡度越大，开始产生径流所需的时间越短，两者亦呈指数关系。径流系数与坡度大致呈线性关系，其随坡度的增加而增加。暴雨、大暴雨、特大暴雨的初始产流时间均在降雨峰值到来之前，因此，峰值位置对三种雨型的初始产流时间没有影响。只有大雨的前峰型的产流时间小于中峰型，中峰型略小于后峰型。降雨峰值出现的时间越晚，径流系数越大。不透水砖、混凝土路面的降雨产流量比较大，土壤入渗量较小，因此土壤前期含水率对不透水路面的径流系数影响不大。不透水砖路面的径流系数比混凝土路面的略小。
[Abstract]:The acceleration of urbanization has led to an increase in the proportion of hardened roads in cities year by year, coupled with the frequent occurrence of extreme weather in recent years. Urban waterlogging often occurs. Runoff coefficient is an important parameter used in the design of rainwater pipe network. However, the runoff coefficient in the design code currently used in our country is the empirical value taken according to the type of underlying surface, and its value does not take into account the slope of the underlying surface. Therefore, it is necessary to study the influence of slope, soil and other factors on Rain Water's runoff coefficient. In this paper, the characteristics of rainfall in Changsha City are analyzed, and the parameters of simulating rainfall in the experiment are determined. The typical soil red soil of Changsha City is chosen as the soil underlying surface of green land, and the slope of the underlying surface is 3 掳~ 7 掳~ (13 掳). The pavement material of paving brick pavement (impermeable brick, concrete pavement, etc.), which is liable to cause urban waterlogging, is used as a kind of underlying surface. A total of 46 simulated rainfall experiments were carried out, according to which the rainfall, slope and location of rainfall peak were analyzed. The influence of these four factors on Rain Water runoff coefficient. The runoff coefficient is linearly related to rainfall, and its value increases with the increase of rainfall, and the longer the rainfall is, the shorter the time of runoff is, and the relationship between them is exponential. The larger the slope is, the shorter the time required to produce runoff is, and the relationship between runoff coefficient and slope is linear, which increases with the increase of slope. The initial runoff generation time of heavy rain, heavy rain and heavy rainstorm is before the peak value of rainfall, so the peak position has no effect on the initial runoff generation time of the three types of rain, only the time of runoff generation of the former peak type of heavy rain is smaller than that of the middle peak type. The mid-peak type is slightly smaller than the post-peak type, and the later the rainfall peak occurs, the larger the runoff coefficient is. The runoff coefficient of impermeable concrete pavement is slightly smaller than that of concrete pavement.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU992.02

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