Public Roads, Vol. 23

Bücher

Angebote / Angebote:

Excerpt from Public Roads, Vol. 23: A Journal of Highway Research, March 1942Where sod is used to line the channel between drop structures the intervening grade may be increased to as much as 5 percent (determined by reference to a velocity discharge diagram such as fig. 2) which in most cases eliminates the need for stepping the grade line.One of the main objections to building drop structures in channels parallel and close to the roadway is the hazard to traffic. The structures also interfere with mowing operations and are always unsightly. In some soils they are difficult to maintain because washing out of the soil occurs below or around the structure. Drop structures are useful, however, in channels normally inaccessible to vehicles on the roadway, as where a channel drops off suddenly into a creek bed. In such cases the drop should be designed as an engineering structure with ample notch capacity and protection against scour at the downstream end.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully, any imperfections that remain are intentionally left to preserve the state of such historical works.