ANALYSIS OF GROUNDWATER-FLOW THROUGH LEAKY MARINE RETAINING STRUCTURES

This Paper presents a simple closed-form mathematical solution to groundwater variations arising from one-dimensional laminar flow through structures in tidal areas. Finite-difference methods are used to study the groundwater response to tidal variations for a non-laminar flow condition where the discharge is proportional to the square root of the differential head. The study highlights the significance of small openings in marine structures on the water pressures and flows through the boundary. It also shows that, for the same openings and ground conditions, the water pressure response for non-laminar flow through the boundary can be significantly greater than that determined for laminar flow. Examples of the practical application of these findings are included to show the effect on the groundwater response to tidal variations of placing natural and geosynthetic filter layers on confined and unconfined gravel aquifers, and of grouting masonry quay walls.