Study of the Stress-strain State in Defective Railway Reinforced-concrete Pipes Restored with Corrugated Metal Structures

Promising technologies for repair of defective reinforced-concrete pipes with the use of corrugated metal structures have been developed. As a result, it was established that the use of corrugated metal pipes in the major repair of reinforced-concrete pipes will eliminate need of stopping movement of railroad and motor transport. This will enable recovery works in a short time with practically no changes in conditions of operation of transport facilities.Vertical and horizontal pressure forces on the reinforced-concrete pipes strengthened with a corrugated metal pipe under the influence of static and dynamic loads from the railway rolling stock were calculated. It was established that the value of both vertical and horizontal pressures on a reinforced-concrete pipe arising from the action of rolling stock decreases with an increase in the filling height because of energy dissipation in the depth of soil. For the filling height above the pipe 1 m, the value of vertical pressure from the load C14 was 7.568 kPa and horizontal pressure was 2.523 kPa. The respective figures for vertical and horizontal pressures were 5.957 kPa and 1.986 kPa for the filling height 2 m and 4.912 kPa and 1.637 kPa for the filling height 3 m.According to the results obtained for static and dynamic pressure forces, the stress-strain state of the pipe in interaction with the soil filling was calculated by the finite element method. The results of calculation of the stress-strain state of the composite pipe showed that the maximum stresses occurring in the vault of the repaired pipe did not exceed maximum permissible values. The magnitude of the stresses in the pipe vault was 0.024 MPa and strains measured 9.3·10–4 m