Phan Viet Dung’s scientific contributions

The hydraulic works on soft soil clay with large horizontal force are easily unstable. For Movable Caisson Dam is a type of lightweight dam, is applied to build in the tidal area so large horizontal force makes it unstable more. The interesting issue is to research the method of stability of structures. Experiments were performed at foundation ditch in Ca Mau, Minh Ha sluice, and sliding concrete foundation at site construction. To increase this friction, grave layers had sprayed under the slab foundation. The result shows friction between movable Caisson Dam and clay soil increase much. This paper demonstrates experiments to calculate optimization of the thickness of gravel layer to ensure the stability of structure and impermeability of bottom slab foundation.

The research results of soft soil type distribution in Ca Mau city is clay very soft state, the content organic is 7.28 %; pH = 3.5, the clay minerals are mainly Illite, Kaolinite, and quartz. Tests determine the amount of salt, the cation exchange capacity the soil shows acidic, salty contaminated many forms of chloride. Samples experiments with cement content and different additives showed a compressive strength axis unrestricted and unconfined tensile acre increase proportional to the cement content and curing time; The amount of additives to achieve the optimal level of 2% Gypsum, Roadcem is 1.5%, and Lime is 4%. With reinforced cement is 200kg/m3. The unconfined compressive strength of samples at 91 days old can be achieved 800 kPa. However, if the extra amount of additive is appropriated samples with flexibility and satisfy the requirements of purpose building.