Page 12 - LWFC Catalog

4PM - Design Considerations and Applications of Lightweight Materials
4:50 PM for Earthquake-Resistant Infrastructure Lightweight materials have
been used in earthquake-resilient infrastructure in seismically active
areas. These materials are desirable because of their low mass density
and relatively high compressibility compared with traditional earthen
materials. A reduction in mass produces a significant decrease in
earthquake inertial forces (i.e., reduces inertial effects and interaction).
Compressible materials can exhibit a substantial decrease in stiffness
during earthquake cycling, reducing kinematics effects and increasing
Tuesday material damping. This presentation shows how these effects can be
used in earthquake-resilient design and construction by showing several
October constructed works.

4PM -
19 4:50 PM Ultra-Lightweight Foamed Glass Aggregate in Roadway
Embankments and Walls The use of ultra-lightweight foamed glass
aggregate (UL-FGA) on roadway projects throughout the U.S. has
greatly expanded in the past few years. DOTs have primarily looked
to UL-FGA as a lightweight fill layer that can be used to eliminate or
minimize the settlement of underlying soft soil layers or to lower loads
on structures or utilities. Fill over areas where there are existing deep
foundations is also a common use for UL-FGA so that concerns of down-
drag or lateral squeeze effects can be minimized. This presentation will
review the engineering properties of UL-FGA that are needed for the
design of UL-FGA in roadway embankments or walls. The attributes
of UL-FGA will be compared to the requirements of MSE wall backfill
specifications. Finally, several case studies demonstrating the use of UL-
FGA in roadway embankments and walls will be shared.

4PM - Slope Stabilization using Lightweight Pervious Cellular Concrete
4:50 PM The Cross Mine located approximately 3 miles west of Nederland,
Colorado is a historic gold-silver mine currently in exploration and
re-development stage. Entrance to the mine was in such a state of
neglect and disrepair from long-term gradual deterioration that it
was not safe to enter. During initial rehabilitation of the portal a roof
collapse occurred a short distance into the mine. Fortunately, the
failure occurred overnight when no personnel were present and no
injuries occurred. However, the collapse completely blocked the mine
opening and daylighted in the slope below a county road. The loss
of material from the roof of the tunnel during the collapse created
a remnant void above the tunnel opening and extreme hazard for
continuing the rehabilitation efforts. The remaining void created by the
portal collapse was backfilled with lightweight pervious cellular concrete
to provide permanent ground support that would stabilize the slope
while allowing the slope to drain. The completed cellular concrete
backfill is significantly stronger than the soil which originally comprised
the slope while imposing only a fraction of the weight. This serves to
increase stability of the slope above the portal and below the county
road substantially. The flowable nature of the backfill also allowed it to
encapsulate the remaining rubble, old timbers which had failed and
the new tunnel lining system such that rehabilitation could continue.
The mass of cellular concrete and rubble remaining in the tunnel roof
(back) creates permanent robust support for the mine entrance. The
previous nature of the backfill also allows groundwater to freely drain
from the slope in order to ensure long-term stability.