翻砂
3.A brief introduction is given to the treatment of the Zeya dam foundation,principles of seepage control and design of the concrete face rockfill dam of the Zeya reservoir.As for the excavation of the sand-gravel zones,except the toe slab and its 1/9 bottom width down stream,the alluvial layers are excavated to the micro-weathered rocks,while the other sections remain unexcavated.Regarding to the treatment of the fracture zones,concrete filling is used for the toe slabs and semi-permeable materials are used for other section.According to the construction characteristics,a filter is placed in the down stream embankment foot.To improve the integrity of the dam foundation and anti-seepage capability consolidation grouting and curtain grouting are adopted.As a result safety,economic benefit,convenience in construction and good performace are achieved.
4.A detailed introduction was made to the properties of the wet coated sand suitable for multi-station shell mould shooting machine; the development of a sort of high strength coated sand with low resin content: the shaping index and wetness adjusting process: analysis and prevention of peel back defect of shells made with overturning hopper process; test method of peel back resistance of coated sand: pinhole defect analysis of high Ni ductile iron shell mould castings and application of anti-pinhole coated sand.
