我处承建的京九铁路吉(安)赣(州)段,共有涵洞125座,4770横向延长米。涵洞多在平江沿岸,沟川交错,地形水势复杂,灌溉渠、排洪沟渠纵横,鱼塘水池星罗棋布,有相当数量的涵洞属灌溉、排洪兼用,这种涵洞的过水形式不同于单一用途的涵洞,我们对不同情况的涵洞应选择的过水形式作一简单介绍。 排、灌兼用型涵洞大体有以下几种情况: (1)灌渠标高与排洪标高相当 这种情况较好处理,即在流水板上留槽作灌溉用,排洪则用涵洞全断面实现。 (2)灌渠标高高于排洪沟但低于盖板底 这种情况可采取在涵洞边墙上挂管或从底部支放渡槽作灌溉用,视水量大小和需要可在一侧挂管,也可在两侧挂管。如果排洪沟两侧 I am at the construction of the Beijing-Kowloon Railway Ji (Ann) Gan (state) section, a total of 125 culverts, 4770 lateral extension of rice. There are many culverts along the Pingjiang River. The Dousheng River is intertwined. The topographic water potential is complex. Irrigation ditches and drainage ditches are vertical and horizontal. There are a large number of culverts in the ponds. There are a considerable number of culverts that are irrigated and drained for flood control. Culverts, we have a brief introduction of the type of over-water that should be chosen for different culverts. Row, irrigation and culverts generally have the following conditions: (1) irrigated canopy elevation and flood discharge elevation quite good situation in this case, that is, in the water board for slot irrigation for irrigation, drainage culvert with full cross-section to achieve. (2) Irrigation ditches elevation higher than the flood drain but lower than the cover bottom This case can be taken to hang pipe in the culvert wall or from the bottom of the aqueduct for irrigation, depending on the size of the water and the need to be in the side of the tube, Can also be hung on both sides of the tube. If the flood drain on both sides