Geoscience Reference
In-Depth Information
Fig. 5.12. nees@UCLA teamat the Four Seasons building inSherman Oaks, CA
Fig. 5.13. UCLA NEES linear inertial shaker
enhance the response of one particular mode over another by force appropriation, which
can be very helpful indistinguishing between closely spaced modes of vibration.
The three eccentric mass vibrators are useful for testing a wide range of structural sys-
tems, including moderate-scale destructive dynamic testing.
3.1.2. Linear shaker
The linear inertial shaker (Figure 5.13) capable of broadband excitation was developed
jointly by Anco Engineers, dSPACE Inc., and Sysendes. The shaker controllers allow
either force or displacement control. The nominal performance specifications for the lin-
ear shaker are a peak force amplitude of 15kips, 30 inch stroke, and 90gpm servovalve
capacity.
3.1.3. Cone penetration testing truck
The UCLA NEES equipment portfolio includes a Hogentogler cone penetration test-
ing truck (Figure 5.14), equipped with a seismic-piezocone to characterize soil consis-
tency, pore water pressure, and shear-wave velocities. The rig has a 20-ton hydraulic
pushcapacity.Therigweightisapproximately6tons,andsideaugersprovideadditional
reactionforces.Therigisequippedwith30mofrodlength.Afullyautomatic5-channel
ESFCS data acquisition system records measurements of cone tip resistance, sleeve fric-
tion, probe inclination, pore water pressure,and shear-wave velocities.
