If I recall the explosive content for the 155 HE round correctly it is 7-8 kg of composition B exposive.  Rain enough of them down on a structure like a bridge, with fuse delay or hardened concrete pieceing type fuzes & eventually one will hit a critical point in the structure.  In school this was called a "Destruction Mission" & was considered something for extreme cases due to the ammo expendenture and the exposure of the batterys firing.  All those shots about guaranteed location of the firing units by evil Warsaw Pact commies.  I cant ever think of ever planning such a mission in any training exercise.  One look at the ammo requirements specified by the JEMS underlined why.