Loess tunnel construction quality control points
3) arch filled with rubble concrete should meet the requirements of the relevant regulations.4) concrete or rubble concrete arch above the back should reach the design strength of concrete arch in the back 70% after construction.
2) the invert, invert the filling layer and dry concrete construction should be concrete accurately, use the template, mechanical tamping compaction. The inverted arch concrete by pumping casting, should use the arch template ensure molding size meets design requirements. The construction of invert arch and filling layer should be completed according to the design of inverted arch concrete construction, the appropriate interval, and then change the proportion of concrete, filling layer of concrete construction;The construction of inverted arch and the cracks and deformation joints should be waterproof treatment according to design requirements, should be in accordance with the relevant provisions of this guide.Invert the overbreak in the allowable range, should be used with the same strength grade of concrete lining casting; overbreak exceeds, should according to the requirements of design and specification of the backfill, shall not use the random hole slag backfill, non intrusive rubble arch section.
The main points of concrete construction of tunnel invert:1) should advance concrete arch wall concrete construction of inverted arch arch and the construction should be removed before water, slag and other sundries, false
