Cost-Effective Maintenance Policy for Sliding Surfaces of Bridge Bearings Using a Gamma Stochastic Process for Forecasting

Table 1

Bearing replacement alert thresholds defined in codes in China, Europe, and the USA.

Code	Alert level 1	Alert level 2
China [4, 20]	1 mm of sliding surfaces remains: recommend replacement	0.8 mm of sliding surfaces remains: immediate
Europe [21]	h ≤ 1: more frequent inspection (2.2 mm ≤ ℎ ≤ tp/2.2, where tp is the thickness of PTFE)	0 protrusion ℎ: immediate
USA [11]	10%–25% of sliding surfaces remains	Na