Prémio Ev.Obra

Portuguese to English Bus/Financial Construction / Civil Engineering Payroll abbreviations

This is from a pay stub from Portugal for a construction worker.

Sorry, no further context. Part of a list of itemized salary information which reads exactly as follows:

Vencimento base
Prémio even.div
Prémio Ev.Obra
Prémio Obra
Ajudas de custo
Sub. alimentação
Trab. Noct. 25%
Trab. Ext. a 100%
Vencim. ferias

Any hints or guesses as to what "Prémio Ev.Obra" might stand for in Portuguese would be much appreciated.

Thanks in advance!