The Latticed Frame Block Method for Protecting Slopes

Abstract

There have been two methods that have been in practice to protect slopes from erosion and rupture caused by rain falls, one is by growing plants on the area, and the other by constructing pavement of concrete, blocks, etc. Growing plants on the area, more especially sodding it, is preferable to the latter both from economical point of view and in consideration of durability of the work i.e. of preservation of natural scenery. Sodding slopes requires lots of human care for extensive periods of time until it begins to show its effect. For it is not easy for sod to flourish on the slope soil.The latticed frame block method which we hereby recommend can surmount this defect of sod; it can make up for its initial defect, and protect the slope from erosion by the work of the surface water, and prevent the seeds of the plants within the squares from being washed off. The latticed frame block method has both the merit of protecting the slopes with its own pressure and the merit of protecting the grass when it is grown.The block itself is a sort of framed block with a L-letter type cross section and a cutwater flange. The blocks placed on the bare slope make a figure of diagonal lattice and divide the broad area into small squares with their cutwater flanges. The surface water in each square, therefore, converges on the latticed frame and drains scattered. Also, the piles driven into the slope at each joining point of the blocks prevent the slope from sliding.Thus the latticed frame block method is considered to have three-fold advantages; protection of the slope with the weight of the blocks, protection of the grass and the effect of utilizing the pile.When the New Tokaido Line was under rapid construction so as to meet the extraordinary demand occasioned by the Tokyo Olympic in 1964, many engineers were deadly earnest in seeking for an effective method to protect the extensive slopes which stretch along the railway. It was the latticed frame block method that successfully met this demand at the time. Since then, the latticed frame block method has been applied in the fill construction of railway, highway, etc., and obtained excellent results in all parts of the country.