أُصْلِحَ الْجِسْرُ. ثُبِّتَتْ أَلْوَاحُهُ وَدُعِّمَتْ دَعَائِمُهُ.
The bridge was repaired. Its planks were secured and its supports reinforced.
The first sentence gives a general report, while the next supplies its principal details. In context, this can be read as clarification or clause-level substitution. The wāw within the second sentence joins two repair operations; it is not a wāw connecting the two main discourse sentences.
If the second sentence instead narrated an unrelated event, that analysis would not hold. The criterion for substitution is that the subsequent clause specifies essentially the same intended assertion rather than contributing a separate topic.