在当前农田水利化的高潮中,到处开挖河道,引水灌田,有的须要横越公路,尤以引水的小型渠道,泄水渠床往往高过路基,若按水渠泄水平面要求,则需将涵台提高,上部石盖板及复士过厚,这样就造成涵洞位置凸出路面,横挡公路,不但有碍美观,而且影响行车时速。抚宁县王各庄乡结合开渠修建公路时,创办了水渠跨越公路改用“倒洪吸”的办法,因地建涵,成效良好。不但不影响过水畅通,还保持路面平坦,这个经验在唐山专区各处正在推广,兹介绍如下:倒洪吸,亦弥倒洪管(如附图)。水渠横过公路,由于地势高,水位低,涵就超出了路面。当修建箱涵或管涵时,可将涵位降低,使涵面及复土保持与路面相平,涵身长度与路基宽度相等;在降洞进水口与出水口处,适当地作出斜坡及护墙。涵洞位置低于水面,公路两侧渠道保持水位平衡,使上流水源到涵洞进口处急速下泄,俟将涵洞灌到一定程度,水源又从涵洞出水口处上升,继续流入下游渠道。涵洞孔径的大小,可依据水渠的 In the current climax of farmland water conservancy, excavated rivers and diversion of irrigated fields everywhere, and some need to cross the road, especially in the diversion of small channels, drainage bed is often higher than the embankment, drainage channel if required by the drainage surface, Taiwan increased, the upper stone cover and complex too thick, thus causing the location of culverts protruding pavement, cross the highway, not only hinder the appearance, but also affect driving speed. Wang County, Funing County, with the opening of roads to build roads, founded a canal across the highway switch to “inverted flood suction” approach, due to the construction of culvert, with good results. Not only does it not affect the smooth flow of water, but also to keep the road flat, this experience is being promoted everywhere in the Tangshan area, it is introduced as follows: inverted flood suction, but also to pay flood control (pictured). Drainage across the road, due to high terrain, low water, culvert beyond the road. When building culverts or pipe culverts, the culverts can be reduced so that the culverts and rehabilitated soils are kept flat with the pavement, and the length of the culverts is equal to the width of the subgrade; at the entrances and exits of the lowered holes, slopes and Retaining wall. The location of culverts is below the surface of the water. The channels on both sides of the road maintain the water level balance, allowing the upper stream to drain rapidly to the culvert entrance, filling the culverts to a certain extent. The water source then rises from the culvert outlet and continues to flow into the downstream channels. The size of the culvert aperture can be based on the channel