Page 161 - Water Standards
P. 161

shall be carried out by staggered joints with a distance of 1 / 2 the stone
                       length. The junction of two adjacent rows of masonry gravel shall be
                       staggered, and large gravel shall be chosen for bricking the channel
                       bottom and slope toe. The larger head of each piece of gravel shall be
                       bricked downward and squeezed in tightly.
                           3  Stone masonry shall be constructed in line with the require⁃
                       ments of Section 2   8 in this specification.
                       3   4   7  Concrete anti⁃seepage shall meet the following requirements:
                           1  Construction of form, reinforcement bar, and concrete shall
                       meet the requirements of Sections 2   7 and 2   9 in this specification.
                           2  In⁃situ concrete. Sliding formwork or mobile formwork should
                       be employed, and concrete shall be placed in line with the leap⁃block
                       sequence method. As concrete is poured, float work shall be carried
                       out in time. For fine and superfine sand concrete, float work shall be
                       carried out twice. After float work, the concrete surface shall be
                       dense, smooth, bright and clean, and no cobbles shall be exposed.
                           3  Shotcrete anti⁃seepage. Strength and thickness of shotcrete
                       shall meet design requirements, and the requirements of SL 377 shall
                       be referred to for shotcrete construction.
                           4  Precast concrete anti⁃seepage shall meet the following re⁃
                       quirements:
                             1) Cracking of the paving seams in masonry with concrete
                                 precast slabs shall be prevented. For filled channel dikes,
                                 precast concrete should be laid when the filling body has
                                 basically finished settling. The mortar strength shall not be
                                 less than M10   Precast blocks should not be too large,
                                 and the length⁃width ratio should be 1 ∶ 1-1 ∶ 1   5  
                             2) Concrete precast slabs shall be laid by cement mortar or
                                 cement mixing mortar, and pointing of joints with cement
                                 mortar. Masonry shall be smooth and stable, and joints
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