A Study Of Physical And Mechanical Properties Of Sediments In Rainwater Inlet Of Beijing

Since China's Economic reform and open up,China's economy has developed rapidly and the urbanization process has become increasingly prominent.Although the economic level is constantly improving in this process,the urban population density is increasing and the building area is increasing,which not only changes the original climatic conditions of the city,but also result in the increasingly apparent contradiction between urban construction and the natural environment.As the capital of China,Beijing has developed significantly,and its hardened ground is increasing.Due to the influence of the monsoon climate and the urban heat island effect,rainfall gradually shows the characteristics of high intensity and short duration.Therefore,when the rainy season comes,the amount of precipitation infiltration decreases and the surface runoff increases.In addition,because of constrained by economic costs.Most urban drainage pipeline systems in Beijing still maintain the once-in-a-year standard when they were originally designed and constructed.As a result,the amount of precipitation that flows into the rainwater outlet exceeds the drainage capacity of the urban drainage pipeline system,and urban waterlogging disasters and water accumulation problems are becoming more and more serious.To alleviate the rain and flood disasters and urban waterlogging problems,which are exacerbated by urban development and expansion,on the one hand,we can increase the research and application of rain and flood management by building sponge cities and other methods so that we can master the scientific method of using rainwater.On the other hand,if the sediment in the rainwater outlet is not cleaned in time,it will seriously weaken the water delivery capacity of the drainage pipe and corrode the pipe,which will increase the problem of urban waterlogging and standing water.At the same time,with the increasing in urban construction,the demand for engineering soil is increasing.Therefore,we can consider putting the sediment in the rainwater mouth into engineering practice,which will turn waste into treasure.In view of this,this article takes Beijing as a research area and selects the main roads in the urban area such as Oumeihui Shopping Center,Anyuandongli Community,Ritan Park,Lianhua River,Third Ring Road,Fourth Ring Road,and other four major cities.159 rainwater outlets were used to sample sediments and do indoor geotechnical tests.Moreover,taking advantage of test data and mastering the range of basic physical and mechanical properties of sediments in the rainwater outlet:water content[29.1,34.9]%,density[1.32,1.93]g/cm³,porosity ratio[0.39,1.02],liquid limit[36.8,61.8]%,plastic limit[25.8,49.3]%,plastic index[5.2,18.1],compression coefficient[0.05,0.48]MPa^-1,compression modulus[3.92,28.40]MPa,cohesion[2.17,12.55]KPa,internal friction angle[22.55,43.62]°.By means of regression analysis,the correlation between various physical and mechanical properties and the corresponding correlation equation are determined.Finally,the soil texture of sediments in rainwater outlets at different locations was classified,and the physical and mechanical properties of each soil texture were combined to study the spatial differences in the physical and mechanical properties of sediments in rainwater outlets.In conclusion,through the above research,it will provide reference for data theory for the application of sediment in the rainwater inlet in the future,and put forward relevant suggestions for the construction of sponge cities.