Page 24 - LWFC Catalog

are areas requiring additional support usually with grouted rock bolts
and timber cribs. Openings are also maintained by cutting down failing
ground to a higher seam. This thins the salt cover and increases the risk
of brine inflow from overlying limestones. An early experiment using steel
arched supports and a low density foamed cement fill to cope with the
continuous entry closure and confine detaching rock without deforming
the arches is described.

1PM - Exploring the Potential: Permeable Cellular Concrete Designed
Thursday 1:50PM for Pollutant Removal Better living through chemistry has produced
incalculable good and many new products and societal advancements,
October however in many locations this good has resulted in substantial pollution.
Just look at the news over the past few years, massive heavy metal spills at
21 the Gold King mine, fly ash pond failure in the Tennessee Valley, potential
red mud failure in Florida, and PFAS contamination throughout military
installations across the US, amongst incalculable others. Permeable Low
Density Cellular Concrete (PLDCC) presents an interesting technique to
help address the myriad of environmental challenges. It is comprised of
cement, which is effectively a limestone base and excellent inorganic
glue, it’s hydraulic conductivity can be modified through mixture
proportions as needed, it can entrain a variety of beneficial components
for pollutant removal, and if needed can allow easy recovery of valuable
rare earth elements after exhaustion. This presentation will present the
supporting research behind PLDCC pollutant removal and present
a variety of areas where future application many be appropriate.
Attendees will understand the basics of mixture proportioning as related
to pollutant removal performance and how particular designs could be
applied for environmental cleanup. We use water filters for our homes,
why not apply water filters for our environment?

1PM - Filling in the Ramp: Backfilling a Construction Access Ramp with
1:50PM Cellular Concrete The future home of the Seattle Kraken NHL team at
the Climate Pledge Arena located in Seattle Washington started with
the renovation of the existing at grade 1962 World’s Fair exhibit which
will now be transformed into a modern 900,000 square ft, 17,000 seat
arena with all modern amenities. The existing shallow bowl of the original
arena was excavated 60 ft. below grade to provide additional seating,
event space, parking and mechanical rooms for the new arena. This
excavation was completed while the original iconic concrete roof in
place and supported on temporary underpinning that hindered a lot of
conventional construction methods. To facilitate construction activities,
a 400 foot long construction access ramp was excavated outside of
the perimeter wall, braced with a complex system of cross lot bracing
and temporary tiebacks. The wall of the arena on this ramp side was
constructed free standing to be backfilled at the end of the project.
Since arenas have no interior floor plates, the wall was unbraced from
either side. To complete the arena, the ramp was to be backfilled
and the arena wall was to be completed with the infill “closure wall
system”. Initially the ramp closure system was designed using structural
fill placed in compacted lifts and series of tierods either tied to concrete
deadman blocks of tied to the exiting soldier piles on the far side of the
ramp. Due to the complex nature of the existing bracing, proposed
snorkel structure built around and above the ramp and relatively large
lateral loads imposed from structural fill, cellular concrete was selected
as a value engineering option for backfilling the ramp. The use of
cellular concrete as backfill reduce the imposed loads on the closure