Study On Recharge Well Model Test Of Thick Sandy Gravels And Mechanism Of Well Flow

Groundwater is not only an important part of water resources,but also the major water supply in many cities.Reasonable utilization of the underground water plays a very important role in social economic development and ecological environment construction in China.With the reform and opening to the outside world,the process of urbanization is accelerating,and the population of the residents is becoming more and more concentrated,which leads to the excessive consumption of groundwater resources in the city.Urban domestic water,industrial water and construction water have caused immeasurable damage to groundwater resources,and even lead to serious consequences.Recharge of groundwater is an effective compensation on groundwater resources.However,due to the deficient understanding and research of flow mechanism of recharge well and the lack of corresponding standard as a reference,recharge well has not been widely used in practical engineering.In order to meet the demand of recharge and spring protection in Ji'nan,the model test of reinjection is set up.Through the experimental data and the theory of pumping well flow,the reverse application and correction of the reinjection well flow theory are realized.Specific research has been carried out in the following aspects:(1)Reinjection model test platform was designed and built,while the test monitoring system was developed to observe the condition of the system.According to the experimental data,the test packing is selected.The indoor gradation test and pumping test were carried out,and the physical properties of the filling layer were obtained according to the geological survey report,which provided the basis for theoretical calculation.(2)The model test of recharge is carried out.Two sets of test contrast groups are designed respectively for two conditions of phreatic water and confined water.The characteristics of underground well flow are analyzed by experimental data.(3)Based on the existing pumping well flow theory,the reverse flow theory of the reinjection well is developed,and the steady and unsteady flow formulas under the condition of phreatic water and confined water are obtained.Through comparison and analysis of the recharge test,an empirical formula suitable for the radius of the steady well flow in recharge is corrected.By means of the assumption of the filter pipe,a quantitative description of the well damage is given.