The population of Southern California relies
on an extensive system of canals and tunnels
to deliver water. Construction of these structures
is an intricate undertaking that requires a
considerable amount of engineering expertise
and attention to detail.
Because of the terrain and site conditions, it
also means that custom solutions to unique
situations must often be devised. When
Shank/Balfour Beatty was contracted to build
the West Tunnel-Inland Feeder in Highland,
California, they determined that site conditions
at the tunnel entrance required a portal
structure not specifed in the original plans.
The contracting/engineering firm designed
an arched structure with 18" thick concrete
walls to protect workers from possible rock
slides at the opening during tunneling operations.
Project Engineer Stuart Lipofsky asked
Symons® by Dayton Superior to propose a
forming system for this important element.
Load calculations and engineering drawings
were provided to Project Manager John
MacDonald for his review. They detailed how
Anchor Clamps attached in sleeves cast into
the straight walls transferred loads from the
forms and concrete and other important details.
Based on this information and a job site
inspection before the first pour, he approved
Shank/Balfour Beatty report that the system
performed exactly as planned. They were
impressed with the speed of this design and
happy to cycle the Flex-Form system through
all four concrete pours in just 10 working days,
safely beginning their tunneling operations.