Research On Numerical Simulation Of Dry Dock Seepage And Its Application

Dock was a kind of hydraulic structure for shipbuilding.It includes dry dock and floating dock. Three sides of the dry dock are connected to the land and the last one was connected to the water. Owing to the high level of the river and underground water,underground water has a great force act on the underground structure of the dry dock.Although drainage decompression facilities can reduce or eliminate the force effectively on the underground structure,owing to lower underground water,it must be cause larger difference of water level and hydraulic gradient.So ensure the stability of seepage and prevent the occurrence of piping and soil flow was necessary for the seepage analysis of dry dock.The experiment method and finite element method or both of them were usually employed at seepage analysis in dry dock problems. However, the high reliable analysis results cannot be obtained quickly due to the complex experiment procedure or enormous computations. And seepage analysis results include seepage water head distribution,velocity distribution and seepage discharge which pass the dock floor.In the practical engineering,seepage discharge which pass the dock floor should be given more consideration.The size of dock floor seepage discharge have a direct relationship between project of drainage facility.If the seepage discharge is too much,the cost of project’s economics and security will be high,so we should ensure the seepage discharge in the reasonable range and the engineering to be economic and safe.Current specification was the design specification of dry dock which was issued by transportation in1987.Through the analysis of current specification, the equivalent total length of permeability contour line in the formula of dry dock seepage discharge was difficult to find the consequence. Adopting the discrete method to equivalent substitution, discreting the permeability contour line from curve to straight,will be easy to generate error.It was inconvenient to the designer in the simplification.In this paper, we were structuring various dry model to numerical simulation considering the influence of dock floor’width,permeable foundation’thickness and impervious curtain.The seepage water head distribution,velocity distribution and seepage discharge about dry dock are successfully calculated based on the independently developed Hydroinfo System by Dalian University of Technology.A theoretical formula based on dimensional analysis was deduced in accordance with the seepage discharge calculatal formula by the point source and line source.ln addition, a new formula for the seepage calculation was also deduced in accordance with the modeling seepage discharge. The accuracy of formula was verified by GeoStudio, which was seepage software from Canada.Meanwhile,we must analyze the influence of head distribution,velocity distribution,and pay attention to the reinforcement of impervious curtain and dock floor.