Research On Sediment Deposition In Drainage Pipes Using Info Works CS Model

With the development of our social economy and urbanization acceleratingcontinually, urban area and population increasing sharply, but city drainage pipelinesproject investment is far lower than the speed of the city development, the citydrainage pipes deposition congestion problems getting more and more serious. So, inorder to improve the operation of the drainage systems, it is necessary to carry outthe research on sediment deposition in drainage pipes.In the paper, we chose study object which located in Yuexiu district newhepuchong river basin of G city, through the investigation and sampling analysis ofthe research area’s drainage deposition, we know the correlation of all factors thatpipe network sedimentary status and the present situation, pipe diameter, slope, pipematerials, catchment area properties, drainage system, etc. We can know differentperiod, different area of sediment particle size distribution and sedimentbiodegradable organic matter, nitrogen, phosphorus pollution levels. Results showsthat, at least half of the area’s pipes have deposited to different extent, and themajority of the sediment are fine sand particles whose diameter are below250μm;Slope has the greatest impact on the pipeline deposition, and that pipeline depositionraises with the increasing of diameter. Meanwhile, deposition in concrete pipes ismore serious than that in PVC pipes. The property of subcatchment affects thedeposition at the same time. The pipes in the old residential district and businesszone that have the most serious deposition. In addition, the deposition of stormsewers is even more serious than that of the combined system. The distribution ofparticles are uneven in different zones and periods; the sediment particles of whichthe diameter are below250μm or within450~900μm enriched60%~80%ofpollutants.Use InfoWorks CS model as the tool, through inquiring the related literature athome and abroad, we determined the parameters of model calculation. Using thefoundation of pipeline GIS data, data flow provided by the relevant departments, andwater quality, sediment thickness data obtained by the field survey, we divided thestudy area into subset of watershed and modeled the initial setup. Chose the similarwater carrying sand force theory to describe the deposition of sediment particles, theerosion of the water quality of Ackers-White Model module, and based on InfoWorksCS we established the drains deposit law model, using online monitoring data and themeasured data of the deposition rate the model. Use the InfoWorks CS model, we predictive simulation pipeline depositioncondition of the study area, we conducted the sensitivity analysis, on the slope, pipematerial, pipe cross-sectional shape, nature of the catchment area, rainfall intensityfactors. The results shows that, the slope and rainfall intensity has the greatest impacton sedimentation, nature of the catchment areas and pipe cross-sectional shape has acertain effect, the materials has a relatively small impact on sedimentation.Explore the sediment accumulation and migration rule on different workingconditions, according to the actual characteristics of G City, we put forward to applyto the municipal drainage pipeline sediment control measures, we test the effect ofthe control of pipeline deposition through the model, this city drainage channel de-positon control the feasible measures were provided. Results shows that, when theHydraulic Flushing Sluice are closed20minutes, the research networks reached tothe best storage times, when the sluice opens instantly, the water velocity complywith the requirements of the Siphon washing speed, and this Hydraulic FlushingSluice has a good effect on sedimentation control; When the Sluice continuousrunning5days in dry weather, there has no deposition in pipes; So, we suggest thesluice running period was5-10days in dry weather, during storms, the runningperiod can increased to15-30days.