结合SWMM模型和海绵城市理念的雨水管网研究

发布时间：2018-11-25 13:07

【摘要】：近年来由于经济的迅速发展和人口数量的增加,城镇的发展日趋月异。与此同时,城市的发展也面临着非常大的环境与资源压力,因此城市难以继续向外扩张发展。由于地面硬化以及城市内湖的缩小等原因,短历时暴雨导致部分城市出现内涝现象,严重危害人们的日常出行和工作。而海绵城市建设通过将雨水下渗、滞蓄等方式,能在很大程度上防治内涝现象,因此在全国范围内得到陆续推广。为了改善城市内涝的问题,人们对排水系统的优化也逐渐重视了起来,国内的部分给排水专家也尝试着去研究SWMM等水力模型,通过应用该模型对天津、北京等地进行实际运用,发现其效果良好。本文将SWMM模型应用到西安市北郊部分区域暴雨径流的模拟计算,然后结合分析结果和海绵城市理念讨论整治措施,主要研究内容为以下四点:(1)根据西安市暴雨强度公式、暴雨雨型计算出设计重现期分别为1、2、3、5、10、20、50年时的2h降雨强度时间序列表;综合土地利用图和各类土地利用类型的不透水率参考表计算出各子汇水区的不透水率;根据地域特征及参考其他文献确定SWMM模型的其余参数。(2)通过SWMM模型分不同降雨重现期进行模拟可知:在设计重现期为1年时,只有片区4的节点Y4-12出现溢流、管段G4-12出现超载,其余节点和管段都在正常状态,流速小于5m/s,在规范范围之内;重现期为2年时,如节点Y3-6和管段G3-6等个别节点和管段出现溢流和超载现象;设计重现期为3、5年时,有小部分节点和管段出现溢流和超载现象,其流速在正常范围内;当设计重现期为10年及以上时,各片区出现不同程度的节点溢流和管段超载现象,其流速正常。针对上述问题,对应地分析问题的原因所在:由于地面硬化等因素导致不透水率较大,地表产流量大;承担汇水的子区域太多,导致排水任务沉重;设计时重现期选择小,部分管径偏小或坡度较缓导致排水不畅。(3)当重现期为3年时,由于汇水区域不透水率大,节点Y3-6出现溢流,可通过绿色屋顶、下凹式绿地、透水铺装等海绵城市改造减小地表径流量;由于下游管径偏小导致节点Y2-1、Y3-2、Y4-12出现溢流,可在调整管径的同时实行透水铺装等措施缓减排水压力;由于汇水子面积太多导致Y1-9、Y2-9、Y3-9、Y4-6、Y4-9出现溢流,可通过对溢流节点上游的道路、建筑物、景观水体等实行海绵城市改造,对雨水进行下渗或滞蓄。(4)当设计重现期为50年时,根据模拟结果计算出需要调蓄的洪流量共220606m3,建议修建调蓄池容积共计222900m3,平均每公顷需要修建调蓄设施容积136.33m3。为保证排涝能力,应该疏通行泄通道,同时根据海绵城市理念对水体进行改造,结合湿地、初期雨水处理设施等增强水体对洪峰以及污染物的控制能力。
[Abstract]:In recent years, with the rapid development of economy and the increase of population, the development of cities and towns is becoming more and more different. At the same time, the development of the city also faces great environmental and resource pressure, so it is difficult for the city to continue to expand and develop outwards. Due to the hardening of the ground and the shrinking of the lake in the city, the short duration rainstorm causes the phenomenon of waterlogging in some cities, which seriously harms people's daily travel and work. The sponge city construction can prevent waterlogging to a great extent by infiltration and storage of Rain Water, so it has been popularized one after another in the whole country. In order to improve the problem of urban waterlogging, people pay more and more attention to the optimization of drainage system. Some domestic water supply and drainage experts also try to study hydraulic models such as SWMM, and apply the model to Tianjin, Beijing and other places. It was found that the effect was good. In this paper, the SWMM model is applied to the simulation calculation of rainstorm runoff in the northern suburb of Xi'an, and then combined with the analysis results and the concept of sponge city, the measures are discussed. The main research contents are as follows: (1) according to the formula of rainstorm intensity in Xi'an, The design recurrence period of rainstorm rain pattern is 1 ~ 2 ~ 2 ~ 3 ~ 5 ~ 5 ~ 10 ~ (10) ~ 20, respectively, and the time sequence of 2 h rainfall intensity in 50 years is listed. Comprehensive land use maps and various types of land use types of water permeability reference table to calculate the water permeability of each sub-catchment area; According to the regional characteristics and other references, the other parameters of the SWMM model are determined. (2) by using the SWMM model, different rainfall recurrence periods are simulated. When the design recurrence period is one year, only the node Y4-12 of region 4 has overflow. G4-12 is overloaded, the other nodes and segments are in normal state, the velocity of flow is less than 5 m / s, which is within the standard range. When the recurrence period is 2 years, there is overflow and overload phenomenon in individual nodes and pipe segments such as node Y3-6 and G3-6, and when the design recurrence period is 3, 5 years, there is overflow and overload phenomenon in a small number of nodes and pipe segments, and the velocity of flow is within the normal range. When the design recurrence period is more than 10 years, there are different degrees of node overflow and pipe overloading in each region, and the velocity of flow is normal. In view of the above problems, the corresponding analysis of the causes of the problem: due to factors such as surface hardening, such as large impermeability, large surface production and discharge, there are too many sub-areas of water catchment, resulting in heavy drainage task; In the design, the selection of recurrence period is small, some pipe diameter is too small or the slope is slow, and the drainage is not smooth. (3) when the recurrence period is 3 years, the node Y3-6 overflows due to the large impermeability of the catchment area, which can be passed through the green roof and the concave green space. Water permeable paving and other sponge city reconstruction to reduce surface runoff; Because the downstream pipe diameter is small, the node Y2-1OY3-2OY4-12 is overflowing, so the drainage pressure can be reduced by adjusting the pipe diameter and implementing the permeable paving at the same time. Due to the excessive area of water catchments, Y1-9OY2-9OY3-9OY4-6 Y4-9 overflows, the spongy city transformation can be carried out on the roads, buildings and landscape water bodies upstream of the overflow nodes. (4) when the design recurrence period is 50 years, the amount of flood current that needs to be adjusted and stored is calculated according to the simulation results, and the volume of storage tank is 222900m3, and the average volume of storage facility is 136.33m3per hectare. In order to ensure the ability of waterlogging drainage, the drainage passage should be dredged, at the same time, the water body should be reformed according to the concept of sponge city, combined with wetland and early Rain Water treatment facilities to enhance the control ability of water body to Hong Feng and pollutants.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU992;TV213.9

【参考文献】