Field Test of Catenary Net to Protect Traffic from Mining Subsidence

It is often necessary to construct roads across areas that have been undermined at shallow depth or that are subject to surface subsidence from other causes. Surface subsidences can be bridged by incorporating a continuous steel net into the road structure. If a subsidence occurs, the net will form a catenary over the void and allow vehicles to pass safely. The paper describe the requirements for the design of such a catenary net and reports on the results of a near full‐size field test. The design depends for its safety on the use of ductile annealed steel for the net and is intrinsically safe, as an increase in the sag of the net reduces the forces it has to carry. The field test showed that theoretical expectations can be realized in practice. It is concluded that on the basis of the field test a prototype catenary‐supported road can be constructed.