Modular Consideration for Tunnel Formwork
Before the work cycle begins, the formwork designer must select the appropriate size and type of tunnel form. The overall dimensions of any tunnel form can be modified by simply adding fit-in sections (fillers). To increase the height, fit-in sections are added to the lower section of the walls, allowing the height to vary anywhere from 7.5 to 10 ft (2.29 to 3.04 m). The span of the tunnel form can also be varied by adding a fit-in section in the center of the deck, allowing the span to vary from 13 to 24 ft (3.96 to 7.32 m). As for the length, the standard dimension is 8 ft (2.44 m), but tunnels can be coupled to form varying lengths.
A majority of the reduction in construction cost and duration can be attributed to the standardization of building modules. The design begins by selecting a bay size that will be repeated time and time again. Because the design will dictate whether the tunnel forming method can be used, the construction process must be closely analyzed, organized, and coordinated from start to finish. This will ensure that construction can proceed with a minimum of labor, and over the shortest duration.
Consistency and simplicity are the easiest ways a designer can substantially reduce construction costs. Maintaining constant dimensions for the different structural elements unifies the project and allows for tunnel forming systems to be adapted. The repetitive room layout assures that the workers can increase productivity based on their learning