Root section, wind turbine blade and methods for producing and modifying a root portion of a wind turbine blade

A method for modifying a root portion of a wind turbine base blade installed in a wind turbine, wherein the root portion comprises an inner wall, an outer wall, a filler between the inner wall and the outer wall, an inner volume defined by the inner wall, and mounting inserts for mounting the wind turbine base blade to a hub of a wind turbine, the mounting inserts being disposed within the inner volume between the inner wall and the outer wall, wherein the mounting inserts are supported by the filler and extend in a longitudinal direction of the root portion and the wind turbine base blade, comprising:

• establishing at least one root portion hole through the inner wall and the filler to at least one mounting insert and/or through the outer wall and the filler to the at least one mounting insert;
• and
• installing a transversal holding arrangement in the at least one established root portion hole in contact with the at least one mounting insert;
• wherein the transversal holding arrangement is installed with at least one inlay beam extending from the inner wall and/or the outer wall into a mounting insert hole of the at least one mounting insert for holding the at least one mounting insert in the root portion during operation of the wind turbine blade;
• and
• wherein the mounting insert hole is provided as a through hole and the at least one inlay beam is located to extend from the inner wall through the mounting insert hole to the outer wall.