Tread For A Heavy Goods Vehicle Tire

Tread (1) for a heavy-duty vehicle tire having a total thickness corresponding to the thickness of material to be worn away during running, this tread having, in the new state, a tread surface (10) intended to come into contact with a roadway when running. The tread comprises at least one hidden cavity (2) forming a new groove opening onto the tread surface after a predetermined amount of partial wear. Cavity (2) comprises two opposite lateral walls (21, 22) connected together by bottom (23) radially towards the inside and by crown part (24) radially towards the outside. Crown part (24) is provided with a plurality of fine grooves (25) extending radially towards the outside from crown part (24) delimiting the cavity and extending in a direction that makes an angle at least equal to 40 degrees with the main direction of cavity (2).