Como sumar 2 columnas de una misma linea

[Libras]

Código SQL:

SELECT *,
CASE WHEN corte8=corte9 THEN Ton8+Ton9  END AS toneladas
 FROM protri01 
WHERE PedPipsa = '2070713' AND
PedPipsa2 = '2070713' AND
PedPipsa3 = '2070713' AND
PedPipsa4 = '2070713' AND
PedPipsa5 ='2070713' AND
PedPipsa6 = '2070713' AND
PedPipsa7 = '2070713' AND
PedPipsa8 = '2070713' AND
PedPipsa9 = '2070713'
 

algo asi??