If water, gas and electrical cables have to pass through three (3) openings provided in the cross section shown in Figure 2, with tangible and scientific arguments specify the adequate opening for water, for gas and for electrical cables.
For safety reasons, the gas line shall be placed in the highest void (3), then the electrical cable in the void (2). The water pipe shall be placed in the bottom void (1).
The above arrangement is based on the thinking of - gas must not below the live electric line, for which could ignite, and live electrical line must not below the water pipe, which could leak.
In reality, this is an ill-advised/problematic application, to place all three utilities in a narrow confined space (beam, trench), that will not permit by the applicable code.
All utility lines have to be exposed, marked, accessible for maintenance.
Each has its own code of the proper location, protection from accident or intentional damage.
They have codes for repair crew set up of the work area, securing the site, providing a safe bypass for traffic or people passing by.
Inside a composite beam is not a practical place for utility lines unless the beam section is large enough to allow access and space for work, and meets the requirements for each utility line like electrical tray insulation and access, etc.