Experimental Design Validation of a "W" Girder Used for the Construction of Mexico City Transportation System

The new Line 12 of the Mexico City Transportation System is under construction. In order to shorten time construction of an elevated segment of the line, a modified version for the superstructure was proposed by the contractor. This new design is based on a postensioned ”W” cross section girder, taking this name because is composed of two postensioned segments of “U” cross section. In this paper we describe those activities carried out in order to register induced displacements in the “W” girder, as a consequence of different levels of loads applied incrementally. The testing was required in a Design Protocol provided by the contractor to City Officials. The maximum load attained was about 85% of the design load as established in the Mexico City Construction Code. The main objective of this work was to verify the structural behavior of the “W” girder under load conditions similar to those of its service life.