【作者】 李娅；

【导师】 杨敏；

【作者基本信息】 西南交通大学 ， 环境科学与工程， 2017， 硕士

【摘要】 城市化进程的加快伴随城镇道路的建设,使得原有的地形地貌和土壤结构发生变化,不透水路面增加。同时随着极端天气的频繁发生,降雨历时短、降雨强度大的局部突发性暴雨频繁发生,严重造成城市内涝[1,2]。设计滞后是造成城市内涝的主要原因,而径流系数是估算降雨净流量的基础资料,也是进行雨水设计流量计算的重要参数[3]。现在雨水管网设计中径流系数的取值,主要参考《室外排水设计规范》(GB50014-2006)和《建筑给排水设计规范》(GB50015-2003)中的规定[4],而设计规范规定的径流系数是按地面覆盖种类确定的经验数值,并没有从工程实际角度出发,把降雨历时、降雨强度、地貌等因素考虑进去。本课题以成都市新津县雨水花园试验基地为研究对象,将修建了雨水花园的2#路和未建雨水花园的18#路作对比研究,收集试验区域和试验期间的降雨资料,分析试验期间的降雨类型、降雨量、降雨历时以及降雨强度等,采用水量平衡原理和等流时线法对整个降雨-产流-汇流过程进行分析,结合两条道路监测的出流流量进行最优拟合,率定试验区域的径流系数,分析其影响因素,为实际工程建设中排水管网的设计提供设计参数,为城市内涝控制理论研究、实际工程设计应用提供理论参考。课题研究成果显示,试验期间采集的降雨数据覆盖多种雨型,存在不同的降雨强度、降雨历时,试验区域涉及四种不同的下垫面,主要为沥青车行路面、人行道、绿化隔离带、原始坡地。以上因素均对试验区域的径流系数产生影响。通过9月5日这天的降雨量和出流量率定得到的2#路和18#道路的径流系数可知,建有雨水花园的2#路的径流系数远小于18#路的径流系数,说明建有雨水花园的道路相对于未建雨水花园的道路具有更好的雨洪调控作用,对控制城市内涝有积极意义;同时对有效降雨期间率定得到的径流系数值分析可知,不同的下垫面径流系数不同,在试验区域表现为沥青道路径流系数、人行道路面径流系数>绿地、坡地路面径流系数的总体趋势,绿地和坡地对降雨有较强的滞留作用;同样的下垫面,径流系数受到降雨量、降雨历时和降雨强度等因素的影响,径流系数和降雨历时和降雨强度呈正相关关系,随降雨历时的延长而增大,随降雨强度的增大而增大。研究率定得到的径流系数与设计规范中的径流系数取值相比有一定的差异,这说明实际的地域环境径流系数受影响因素复杂,波动较大,在进行工程设计时需要因地制宜,综合考虑[4]。更多还原

【Abstract】 Accelerated urbanization process With the construction of urban roads,the original terrain and soil structure changes,impermeable pavement increased.At the same time with the frequent occurrence of extreme weather,Short-duration and heavy rainfall of local occur frequently,causing serious urban waterlog.Design lag is the main cause of urban waterlog,and runoff coefficient is the basis for estimating the net flow of rainfall data,and also the important parameters of rainwater flow calculation.The current value of the runoff coefficient in the design of rainwater pipe network is mainly based on the provisions of "Outdoor Drainage Design Code"(GB50014-2006)and "Design Code for Building Water Supply and Drainage"(GB50015-2003),and the design runoff The coefficient is the empirical value determined by the type of ground cover,and not from the practical point of view,the rainfall duration,rainfall intensity,geomorphology and other factors into account.In this paper,the experimental base of the rain garden of Xinjin County,Chengdu,China,and there is a comparative study between the#2 road with rainwater garden and the 18#road without rainwater garden.Collect the rainfall data,and analyze the rainfall type,the rainfall duration,the rainfall intensity etc.Study the rainfall-runoff-confluence process through the water balance principle and isometric time-line method.Combining with the measured outflows data of the two roads,find the optimal fitting model,calibrating the runoff coefficient and analyze the influence factors.Which provides design parameters for the design of drainage network in practical engineering construction,and provides theoretical reference for urban flood control theory research and practical engineering design and application.The research results show that the rainfall data collected during the experiment covers a variety of rain patterns,there are different rainfall intensity,rainfall duration,the test area involves four different underlying surface,mainly asphalt road,sidewalk,green belt,Raw slopes.The above factors have an impact on the runoff coefficient of the test area.From the runoff coefficient of 2#and 18#which is determined by the rainfall and outflow rate on September 5 can be seen,the runoff coefficient of the front is much less than the behind.It is suggested that the road with rainwater garden has a better effect on the flood control.It has positive significance to control the city waterlogging.At the same time,the results show that the runoff coefficient is different in different test areas,the runoff coefficient of the asphalt road and pavement surface is lager than the runoff coefficient of the green land and the slope.That is the slope has a strong retention effect on rainfall;When the underlying surface is on the same,runoff coefficient are affected by factors such as rainfall,rainfall duration and rainfall intensity.The runoff coefficient and rainfall duration and rainfall intensity are positively correlated with the increase of rainfall duration,and with the increase of rainfall intensity Increase.The runoff coefficient obtained by the study rate is different from the runoff coefficient in the design specification,This shows that the actual regional environmental runoff coefficient is affected by the complex factors,large fluctuations in the engineering design needs comprehensive consideration of local conditions.更多还原