A study on Electrical Separation Joint in the slab track

A part of the signaling systems related to a rapid transit railway is using the track circuit to detect trains and to deliver train operation services on carriage. To compose a track circuit, it is necessary for a rail to divide electrically. The length for dividing a rail electrically is called electrical separation joint. If it is not correctly set up, it effects on the close frequency on track circuit. Then, it makes an accident or makes a train not receive information under 0.8[A] that is the amplitude of minimum current on the track circuit. So, it is important to set up the length of the electrical separation joint. On the slab track, there are intervals of insulated reinforcing bars and ones of not insulated reinforcing bars by the electrical separation joint. In current, whether insulated or not, all intervals use the length of the electrical separation joint. After all, a problem is occurred that 0.8[A], the standard current value on the track circuit, is not flowed on the intervals where reinforcing bars are not insulated. In this paper, we numerically analyze the length of the electric separation joint by the track circuit frequency of the intervals not insulated on the slab track. Also, we calculate the amplitude of the inductance established at the electrical separation joint, numerically. We demonstrate that 0.8[A], the standard current value on the track circuit, flowed throughout Matlab program and PSpice program.