Abstract
Angle iron posts are sometimes used as materials for low cost fences. However, it is not clear whether angle iron posts can be used for fencing instead of the manufactured steel posts. The experiment using three types of post section with 3×30, 3×40 and 4×50mm angle iron posts was carried out on two pastures with different bearing capacity. Each experimental fence had 4 spans with a 4m post-interval, with the driven depths of 55 and 65cm and the plane angles of 60, 90 and 120 degrees between both sides of two spans, respectively. While loading the concrete weights on the wire to simulate snow loads, the lean of the corner posts was measured at 110cm height up to 10 degrees. The soil bearing capacity from the surface to 30cm in depth was less than lOkgf/cm^1 in the soft pasture ground but over 15kgf/cm^2 in the hard pasture ground. From the relationship between the load and the lean of corner posts, the larger post type needed more weight than the smaller one to achieve the same lean as the corner post. The post lean is mostly related to the load, causing it to bend, and the hard pasture ground allowing the corner post to lean less than in the soft pasture ground. Thus, in order to obtain a larger bearing capacity for the corner post, not only is a larger post necessary but also harder ground. Furthermore, in the soft pasture ground the smaller post has a similar lean independent of the difference in depth, and the larger post type leans less in a 65cm depth than in a 55 cm depth. On the other hand, the effect of the driven depth on the corner post lean was little or negligible in hard ground. In the case of plane angle, the softer the pasture ground, the more the corner post with a small plane angle leans. As a result of the experiment, we can recommend 4×50 mm angle iron post as fence material because of its stability. However, in the case of using angle iron posts, we must think about the durability for the rust on posts because of no painting, and about the easy fence maintenance without the snow damage in snowy areas.
