EXPERIMENTAL AND NUMERICAL ANALYSES OF UPRISING MOISTURE IN FINE GRAINED SOILS

Houman Soleimani-Fard ； Diethard König ； Meisam Goudarzy

《Journal of GeoEngineering》 16卷1期 (2021/03) Pp. 1-14

https://doi.org/10.6310/jog.202103_16(1).1

摘要

Due to the microstructure of clayey platelets, fine-grained soils can retain a considerable amount of moisture. In spite of having relatively low permeability, this moisture can be transferred through the soil body even if the soil is not saturated. Due to the capillary action, deep underground water can rise upward in a soil profile consisting of clayey layers even up to several 10 meters. This phenomenon causes a thick unsaturated zone with gradually decreasing water content. Fine-grained soils are widely available around the world, not only in the natural soil strata but also in man-made earthen constructions, e.g., embankment dams, waterproofing layers, or masonry walls. In this research to model a clayey profile, a block of fine-grained material was constructed using smaller clay bricks. The uprising moisture through the block and its consequent volume changes were recorded during a test. In another block, a countermeasure protection method (base ventilation method) was utilized to minimize the capillary moisture, which was exposing lower parts of the block to open air. Experimental observations proved that the applied method is able to reduce the maximum height of moisture uprise to around 50% and the consequent heave to around 30% of unprotected condition. Both unprotected and protected conditions were simulated numerically. Experimental and numerical simulations proved to be in a good match. Further geometries and protection schemes were also numerically modeled to assess the efficiency of the studied countermeasure method with various conditions.

關鍵字

Uprising moisture ； fine grained soils ； suction ； SWCC ； countermeasure method