METHODS FOR REINFORCING EXISTING LATTICE FRAME STRUCTURES HAVING HOLLOW STEEL PRIMARY ELEMENTS, PARTICULARLY STEEL TOWERS WITH TUBULAR LEGS

摘要

A series of alternative related methods for reinforcing an existing lattice frame steel structure, having substantially vertical Hollow Primary Elements, offering the option to choose between improving only compressive load-bearing capacity of said hollow primary elements, or improving both their compressive and the tensile load-bearing capacities. The compressive load-bearing capacity of said primary elements is increased by filling their internal cavities with non-shrink cement-based grout, in a slow and low-pressure procedure, hence ensuring the applicability of the present invention to practically any existing steel structure with hollow primary elements, regardless of their capacity to withstand internal pressure. The tensile load-bearing capacity of all, or any part of said primary elements is increased by the insertion, prior to the grout-filling, of a longitudinal, continuous and substantially concentric tensile reinforcement member into each respective primary element, and anchoring it properly to its bottom. An axial pretension of predetermined magnitude is applied to the tensile reinforcement member prior to the grout-filling.