kaksoisrengasmenetelmä

The kaksoisrengasmenetelmä, or double ring method, is a technique used in soil mechanics and hydrology to measure the hydraulic conductivity of unsaturated soils in situ. It involves the insertion of two concentric rings, typically made of metal, into the soil surface. The outer ring serves as a barrier to prevent lateral water flow from the inner ring, thereby ensuring that the water applied to the inner ring infiltrates downwards.

Water is applied to the inner ring at a constant rate, and the resulting steady-state water table depth is monitored. This allows for the calculation of the soil's hydraulic conductivity, which is a measure of how easily water can flow through it. The method is particularly useful for investigating the complex hydraulic properties of soils in their natural, undisturbed state, where laboratory tests might not accurately represent field conditions.

The kaksoisrengasmenetelmä is a widely adopted field method for characterizing soil moisture movement. Its effectiveness lies in its ability to simulate in-situ infiltration conditions, providing more realistic conductivity values compared to disturbed soil samples. Careful consideration of ring dimensions, water application rates, and the duration of the test is crucial for obtaining reliable results. Environmental factors such as rainfall and existing soil moisture content can influence the measurements and need to be accounted for in the interpretation of the data.