Laboratory Scale-down Test For Hydraulic Fill Method Of Songhua River In Harbin

With the advantages of low cost and environmental protection,the hydraulic fill method has become an ideal way for reclaiming land in areas along the rivers or seas.What's more,this technology also plays an significant role in the construction of infrastructures in coastal areas of south China.However,the internal and external factors which affect the dredger filling are complex,and they often interact each other.There are much restrictions when performing in situ test to study the dredger filling technology.And the existing devices for laboratory simulation tests of hydraulic fill has the defect of incomplete processes,which make it is impossible to reflect the engineering practice completely.So the construction period in a practical project is difficult to determine.In this thesis,a dredger filling project which located on the North Bank of Songhua River in Heilongjiang Province is chosen as the research object.Based on the principles and processes of dredger filling,a set of device employed to simulate the actual dredger filling more really in door was developed.Moreover,the test results of indoor dredger filling are used to predict the construction period of dredger filling.A formula which considers the elapsed time of indoor dredger filling,the volume of slurry collection bag,the flow velocity of slurry pump,the diameter of sand conveying pipe and the ratio of water to sand in the dredger filling mixture was established to predict the construction period of practical project.The applicability and reliability of the formula are verified by the related data obtained at the construction site.The main research work are as follows:1.The principles and technologies of hydraulic fill method are analyzed.Considering the advantages and disadvantages of the existing devices for laboratory tests of hydraulic fill,a set of indoor simulation device for dredger filling was developed,and its main components and functions were presented.This device can simulate the practical dredger filling process more completely.2.The self-developed device was applied for the simulation of dredger fillingprocess.A series of Consolidation Test and Direct Shear Test were conducted to assess the performance of the device.And consolidation characteristics and shear strength of the fills were obtained and analyzed,which verified the reliability of this method.3.A formula used for the prediction of construction period of practical hydraulic fill project was established,and the elapsed time of indoor dredger filling,the volume of slurry collection bag,the flow velocity of slurry pump,the diameter of sand conveying pipe and the ratio of water to sand in the dredger filling mixture were taken into consideration in this formula.The data obtained in laboratory and construction site were employed to check the feasibility of the formula,and the results manifested that it is reliable to predict the construction period of practical hydraulic fill project with this formula.