Study On Technology Of Urban Rainwater Biological Retention Pool

With the rapid development of urbanization,the soil and stone pavement is gradually replaced by hardened pavement and blocking the natural ecological water circulation system,in addition to the effects of extreme weather,urban waterlogging disasters are frequent in the country.In recent years,the low impact development measures have been widely spread across the country,which is regarded as the basic concept of sponge city construction,biological detention pool is also a kind of technology that is widely adopted among the development measures.It is not hard to see from the internal structure and operation mode of traditional biological detention pool,the biological detention pool may lose its due function and role due to the defects in structure and process design,causing the trapped pool to block and so on.In this paper,we first carry out a comprehensive study on several common technical measures for low impact development and analyze the respective application conditions and its advantages and disadvantages,and analyze the construction technology and structure type of the biological detention pool emphatically,on the basis of elaborating the design principle of biological detention pool,the paper analyzes the internal structure of conventional biological detention pool and the principle of action to rainwater treatment.The paper points out the problems of the traditional biological detention pool on the basis of fully studying the process principle and design theory of the traditional biological detention pool,such as the internal congestion and the loss of its heavy rain after long operation;difficulties in maintaining management;insufficient structural optimization;the coordination of pre-treatment facilities and high level design.The paper proposes several improvement techniques,such as internal structural optimization,rainwater interception baskets and interception baskets,and eddy pool pre-treatment.In this paper,through the experimental study,it first confirms the urban rainwater surface runoff under the traditional biological detention pool due to design unreasonable clogging and loss of the original function of the situation.At the same time,it is found that when the biological detention pool loses its function,the coating layer contains a lot of sand and the filter layer contains too much mud;the lower the rainwater concentration into the biological detention pool,the better the cleaning effect the faster the infiltration time,indicating that the reduction of the solid content of rainwater entering the biological detention pool is an effective measure to protect the long-term use of biological detention pool;And when the downstream water level gradually increases,the upstream biological retention pool on the rain treatment effect was significantly worse.Experiment on the inflow water front pretreatment research is found that small eddy pool can effectively separate the mud and rain,to increase the lifespan of the biological detention pools and reduce the rainwater detention pools system operation maintenance difficulty.The results of the test and the theoretical analysis show that the pre-treatment of small eddy pool has the advantages of small footprint,flexible arrangement,convenient cleaning,good effect,low construction cost,long service life and so on.It can be designed and arranged according to the site conditions.