Corrosion Protection of Underground Structures

Abstract

The article is aimed at achieving increased corrosion protection of underground communications and structures in the area of influence of stray currents of electric rail transport of direct current through the use of active means of protection. It should be noted that the length of underground communications and structures is increasing every year, and less and less attention is paid to their protection against the effects of corrosion processes. It is especially important to pay attention to corrosion protection of underground communications and buildings in cities with rail electric transport. The evaluation of the condition of the existing underground structures, which are located in the zone of influence of rail electric transport of direct current, is analyzed, the variants of effective and energy — efficient means of active corrosion protection are analyzed and selected. The problem of corrosion destruction of underground communications and structures in the conditions of cities with the presence of electric transport is considered. The mechanism of metal corrosion process is described and the main factors that accelerate the destruction of metals are indicated. Technical measures are proposed to minimize the influence of external factors on the acceleration of the corrosion process of metals. It is proved that when determining the potentials of underground communications and structures, which are caused by leakage currents from the anode grounding, the grounding itself can be replaced by a point grounding. One of the promising means for the implementation of corrosion protection of underground structures is the use of a device for corrosion protection of underground structures. The Department of Intelligent Power Supply Systems of the Ukrainian State University of Science and Technology has developed means of active protection against corrosion destruction of underground communications and structures, which have the following technical and economic advantages: unification of protections in all potential zones of rails; reduction of capital expenditures; elimination of the expense of electric energy for food of stations of cathodic protection and the strengthened electric drainages; reduction of losses of electric energy in rail networks due to shunting of rails by drainage devices; removal of additional positive potential imposed on the rails by reinforced electrical drainage, and improving the corrosion of the structures attached to the rails (reinforced concrete supports and foundations of the catenary and other structures).