The problem of expansion and contraction of the bridge

Due to changes in the ambient temperature, the steel cable tray will expand and contract. The outdoor cable tray is greatly affected by temperature. For example, the maximum ambient temperature is 40 ℃ and the minimum temperature is -20 ℃, then the maximum shrinkage of the cable tray is calculated as follows:

Δt = 11.2 × 10-6 × 60deg (degree) × 1000mm

It is concluded from this:

When the temperature difference is 60 ℃, Δι = 0.672mm / m

When the temperature difference is 50 ℃, Δι = 0.560mm / m

When the temperature difference is 40 ℃, Δι = 0.448mm / m

Expansion joints should be considered in the cable tray of the straight section of the engineering design. The spacing of the expansion joints is recommended to be determined as follows:

50m when the temperature difference is 40 ℃;

40m when the temperature difference is 50 ℃;

40m when the temperature difference is 60 ℃;