Tread for a tyre for a heavy goods vehicle, this tread having a thickness H of wearing material and intended to provide rolling contact with a road surface, this tread comprising: - at least two circumferential grooves of depth P at least equal to the thickness H, these circumferential grooves delimiting at least one intermediate row and two edge rows axially delimiting the tread, - a plurality of V-shaped oblique grooves, each oblique groove comprising branches (31, 32) making an angle at least equal to 30° and at most equal to 60° with the axial direction, these oblique grooves having a width at least equal to 5 mm and at most equal to 12 mm and a depth at least equal to the thickness H, - the circumferential grooves and the oblique grooves delimiting a plurality of V-shaped blocks in each intermediate row, that is to say such that each block comprises a convex part and a concave part, - a plane P dividing each V-shaped block into two parts and being defined as being perpendicular to the axis of rotation of the tyre and passing through the forward-most points of the convex part of each block, this tread being characterized in that: - in each V-shaped block, and on either side of the plane P that divides each block into two parts, there is formed at least one canal below the tread surface, this canal having a width at least equal to 2 mm and at most equal to 6 mm and being intended to generate a new groove after a predetermined amount of partial wear, each canal when new comprising openings (51, 52) that open into the oblique grooves, and in that - a bridge of material is formed between the V-shaped blocks considered in twos, this bridge of material connecting a convex part of one block to the concave part of an adjacent block in the same intermediate row, this bridge of material occupying heightwise and from the bottom of the oblique grooves at least 40% of the depth of the oblique grooves and doing so over a width at least equal to 10 mm, this bridge of material being suitable for not closing the openings (51, 52) of the canals. - at least two circumferential grooves of depth P at least equal to the thickness H, these circumferential grooves delimiting at least one intermediate row and two edge rows axially delimiting the tread, - a plurality of V-shaped oblique grooves, each oblique groove comprising branches (31, 32) making an angle at least equal to 30° and at most equal to 60° with the axial direction, these oblique grooves having a width at least equal to 5 mm and at most equal to 12 mm and a depth at least equal to the thickness H, - the circumferential grooves and the oblique grooves delimiting a plurality of V-shaped blocks in each intermediate row, that is to say such that each block comprises a convex part and a concave part, - a plane P dividing each V-shaped block into two parts and being defined as being perpendicular to the axis of rotation of the tyre and passing through the forward-most points of the convex part of each block, this tread being characterized in that: - in each V-shaped block, and on either side of the plane P that divides each block into two parts, there is formed at least one canal below the tread surface, this canal having a width at least equal to 2 mm and at most equal to 6 mm and being intended to generate a new groove after a predetermined amount of partial wear, each canal when new comprising openings (51, 52) that open into the oblique grooves, and in that - a bridge of material is formed between the V-shaped blocks considered in twos, this bridge of material connecting a convex part of one block to the concave part of an adjacent block in the same intermediate row, this bridge of material occupying heightwise and from the bottom of the oblique grooves at least 40% of the depth of the oblique grooves and doing so over a width at least equal to 10 mm, this bridge of material being suitable for not closing the openings (51, 52) of the canals.