Kenneth H. Stokoe, II Jennie C. & Milton T. Graves Chair In Engineering

1. Raptor (Mid-Size Shaker) • Highway legal truck • 32 ft long, 8 ft wide, weight = 41,200 lbs • Vertical mode Peak Force = 27,000 lbs • Rattler (Horizontal Shaker) • Off-road truck; • 29 ft long, 8.5 ft wide, weight = 54,500 lbs • Shear mode Peak Force = 30,000 lbs • Data Acquisition Systems • VXI system: 64 channels of acquisition at a sampling rate of 50 kS/s and 8 channels of acquisition at a sampling rate of 196 kS/s. • Data Physics system: 32 channels of acquisition at a sampling rate of 200 kS/s • Sensors • 64 of 1-Hz vertical geophones • 24 of 1-Hz horizontal geophones, • 12 of 10-Hz 3-D geophones, • 13 of Trillium Compact, 3-component, 120 second seismometers • Prototype in-situ liquefaction sensors, • Cone penetrometer test (CPT) and seismic CPT equipment (a) Vertical Force Output (a) Horizontal Force Output Theoretical force outputs of the five mobile shakers (http://nees.utexas.edu) Large-Scale Mobile Shakers and Associated Instrumentation for Dynamic Field Studies of Geotechnical and Structural Systems Kenneth H. Stokoe, II Jennie C. & Milton T. Graves Chair In Engineering Clark R. Wilson Wallace E. Pratt Professor in Geophysics Ellen M. Rathje Warren S. Bellows Centennial Professor in Engineering What is NEES? The George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES) is a collection of state of art, shared-use, experimental sites for earthquake engineering that are geographically-distributed throughout the country, but networked together via the NEESgrid computational infrastructure.  The NEESgrid links researchers together via the high-speed internet and provides tools for remote participation, teleobservation, and collaboration. There are 14 equipment sites that are funded by the National Science Foundation (NSF). The 14 sites have been developed at major universities throughout the United States. The sites provide the earthquake engineering community an unprecedented infrastructure for research and education. What is nees@UTexas? nees@UTexas is an equipment site that specializes in dynamic field testing using large-scale shakers.  The nees@UTexas equipment includes five mobile shakers that have diverse force and frequency capabilities, an instrumentation van and trailer that house state-of-the-art data acquisition systems, and a large collection of field instrumentation.  This equipment is connected to the NEESgrid via a wireless modem.  The nees@UTexas field equipment can be used in a variety of applications, including shear wave velocity characterization, liquefaction testing, geophysical testing, and dynamic testing of structures.  • T-Rex (Tri-axial Shaker) • Off-road buggy; • 32 ft long, 8 ft wide, weight = 64,000 lbs • Three vibrational orientations • Push-button transformation of shaking orientation • Shear mode Peak Force = 30,000 lbs • Vertical mode Peak Force = 60,000 lbs • Liquidator (Low Frequency Shaker) • Off-road buggy; • 32 ft long, 8 ft wide, weight = 72,000 lbs • Two vibrational orientations • One day shop transformation of shaking orientation • Shear mode Peak Force = 20,000 lbs • Vertical mode Peak Force = 20,000 lbs • Thumper (Urban Shaker) • Built on a International 4300 truck; • 27 ft long, 8.5 ft wide, weight = 24,800 lbs • Three vibrational orientations • Four hours field transformation of shaking orientation • Shear mode Peak Force = 6,000 lbs • Vertical mode Peak Force = 6,000 lbs • Big-Rig • 26 wheeler tractor-trailer rig for shipping T-Rex, Liquidator, and Rattler • Overweight permit required • Fuel-Supply Truck • Carries diesel fuel for T-Rex, Liquidator, and Rattler in the field • provides a working platform for maintenance and CPT tests • Instrumentation Van & Trailer • A customized Chevrolet cargo van provides an air-conditioned workspace • A 8 ft by 16 ft cargo trailer provides additional working and storage space • Hydraulic Cylinder with Adjustable Platform • Mounted at the rear of T-Rex • Platform for installing and retrieving liquefaction, CPT, and seismic CPT sensors