Sand and gravel aggregate mining and material production, prefabricated blocks for the top arch of the dam gallery, completion of the auxiliary dam foundation, slope support and other working surfaces to strengthen the quality control,
Quality control shall be strengthened for sand and gravel aggregate mining and material preparation, precast blocks for the top arch of the dam Gallery, completion of auxiliary dam foundation, slope support and other working surfaces,
Quality control should be strengthened in aggregate mining, material preparation, precast block of top arch of dam corridor, completion of auxiliary dam foundation, slope support, etc.