Water flow between soil aggregates

摘要: Aggregated soils are structured systems susceptible to non-uniform flow. The hydraulic properties depend on the aggregate fabric and way aggregates assembled. We examined behavior of an packing. focused conditions when water mostly flows through aggregates, leaving inter-aggregate pore space air-filled. were packed in 3 mm thick slabs forming a quasi two-dimensional bedding. larger wetted with embedded smaller equilibrated at lower content. exchange between wet drier was monitored by neutron radiography. three-dimensional arrangement reconstructed tomography. flow turned out be controlled contacts bottle-necks that slow down bottle-neck effect is due narrow cross section contacts. simulated considering contact area as key parameter. In order match observed flow, must reduced one two orders magnitude relative obtained from image analysis. narrowness air-filled voids within