Page 158 - Water Standards
P. 158

ment soil, stone masonry, concrete, geomembrane, asphaltic con⁃
                       crete, etc. The technical requirements of materials are listed in rele⁃
                       vant regulations.
                           2  The deviation in elevation, size and smoothness of unlined
                       cross sections shall meet the requirements of Table 3   4   4-1  
                             Table 3   4   4-1  Allowable deviation for the channel section

                                                           Allowable deviation (mm)
                                     Item
                                                         Soil channel  Stone channel
                                 Bottom elevation        ± (20-30)    ± (30-50)
                                   Centerline              20-30        30-50
                                  Bottom width           + (30-50)    + (50-100)
                                 Top opening width       + (40-80)    + (50-100)
                               Top elevation of the dike  + (20-30)   + (50-100)
                          Smoothness of bottom and inside slopes     <30 for convex
                                                         ± (20-30)
                             ( checked by 2m length ruler)           <100 for concave
                        Note: The larger values are applicable for large and medium⁃sized channels, and the
                            smaller values for small ones.
                          3   Allowable deviations in smoothness and size of the lined
                      channels are listed in Table 3   4   4-2.

                               Table 3   4   4-2  Allowable deviations of lined channel
                                      Item                Allowable deviation value (mm)
                               Channel bottom elevation    ± (10-30)   ± (10-20)
                                 Channel centerline        ± (10-30)   ± (10-20)
                                Channel bottom width       + (20-40)   + (30-50)
                              Upper opening width of section  + (30-50)  + (40-60)
                                    Smoothness             ± (10-20)   ± (10-20)
                                           In⁃situ placement  ±20         ±20
                        Expansion joint interval
                                           Precast concrete  ±50          —
                        Oblique length of slope of anti⁃seepage structure  + (10-20)  + (10-20)

                                                                            1 5 1
   153   154   155   156   157   158   159   160   161   162   163