SPEAKER 1: Now in our tour we go to Cornell University, and the clip we're about to see is the largest displacement experimental facility for studying the performance of very lifeline systems during earthquakes. So it's my pleasure to introduce the principal investigator for this site, Professor Harry Stewart.
Harry is an associate professor of the School of Civil and Environmental Engineering, and Director of the Civil Infrastructure Laboratory at Cornell. Harry?
FEMALE NARRATOR: Welcome to the NSF/NEES Large Displacement Facility for Lifeline Systems and part of the Harry E. Bovay, Jr., Civil Infrastructure Laboratory Complex, operated by the School of Civil and Environmental Engineering at Cornell University. Now we are in the George Winter High Bay Area.
The purpose of the NEES experimental complex is to evaluate the effects of very large displacements, which are generated during earthquakes on underground and above ground lifelines. Lifelines are the facilities that deliver the resources and services critical for modern communities. They include water supply, gas and liquid fuel networks, electric power, transportation systems, waste conveyance, and telecommunications.
HARRY STEWART: I'm Harry Stewart, director of the Civil Infrastructure Laboratories here at Cornell University. And I'm standing in our NEES Cornell facility for Large Displacement Testing for Lifeline Systems.
Our facility consists of a high wall which can be configured to be over three stories tall, and this is used to resist the forces that we would apply with large hydraulic actuators to above-ground structures such as bridges and building columns. The actuators are capable of up to six feet of displacement in one direction, or they can be cycled, plus or minus three feet in either direction.
Also part of this facility is a long, low, and modular wall. This wall is used to resist the forces that we would apply to large testing basins that are placed in this portion of the lab floor. These testing basins then are used to bury underground facilities, underground lifelines-- pipelines, telecommunication systems, things of that nature-- and we test them to evaluate their response to earthquake loads.
This wall also is modular. It consists of a series of blocks weighing between seven to 10 tons. It's clamped together with a system of reaction bolts applying nearly 1 and 1/2 million pounds clamping force.
Also built into this facility are features that you cannot see that are very important to the functionality of this unit. In the floor, we have a series of rock anchors that takes the loads that are clamping down this wall down 30 to 40 feet into bedrock. We have nearly 9 million pounds of clamping force in this system.
What we're going to do now is perform a demonstration. When ground movements occur, they can impart large forces to things buried within the soil. We're interested in pipeline response. The experiment that we're going to do today involves the use of polyethylene pipe.
When ground movements occur, pipelines can buckle or collapse like an accordion. If we can design these so that they can buckle upwards, our lifelines will still be able to convey the critical materials that they're bringing us-- heat, power, water, communications-- but they will survive the earthquake.
We're going to demonstrate an experiment for you now. To comment on this experiment, I'm going to introduce Mr. Tim Bonds, the director of technical services here at Cornell University.
TIM BOND: I'm Tim Bond. I work with our NEES team to design, build, and coordinate the testing of our large-scale tests. These two soil boxes are intended to simulate the kinds of forces and displacements that we would expect to see applied to a buried pipeline in a large-scale earthquake event. Each box is 30 inches wide and 30 inches deep, and has a pipe-- a 30 foot long polyethylene pipe-- buried in it.
You can see that there is a buckled pipe in the backward box, or in the box in the back. This is the result of a test that was done this morning. We will use a large hydraulic cylinder to apply a compressive force to squeeze the pipe, which is restrained by our high wall.
I'm going to check with Brett Shelton, our NEES operations manager to see if he is ready to start our test. He'll be operating the test today. Are you ready, Brett? OK.
Brett's going to start the test. And over the next minute, we will see the pipe that's buried in this box have applied to it some large force and 16 inches of deformation. The 16 inches of deformation will happen over one minute.
You can see that the soil is buckling in the center of the box. The pipe is pushed. And as the pipe is pushed, the force on the pipe causes the pipe to begin to bend. The pipe bends, and the soil reacts against that bending. This is soil structure interaction.
And this test is a good example of what would happen to an axially coupled force in a pipe buried in a typical backfill condition for a gas main. This is a six-inch diameter high density polyethylene pipe. It's typical of the local gas main distribution. It's not typical of the large transcontinental distributions.
You can see this pipe is still coming up. This is about a one minute test. The peak force on this will have been on the order of 25,000 pounds. What you've seen so far is a test in which we use our reaction wall-- the tall wall-- to hold one end of the pipe, the short wall to hold the other end of the pipe, and an actuator, using an actuator to push on the pipe, and using our computer control and data acquisition to control the whole test.
What you haven't seen is that we gather the data and send it to a site in Illinois as part of the NEES grid to make that data available for other sites to use online, real time, to be part of a large scale distributed test. We have also sent four video feeds from four cameras around the lab so that distributed sites can monitor our test and see what we're doing, and then get back to us.
HARRY STEWART: Well, you've seen some of the capabilities for our NEES facility. We're proud to be part of the George E. Brown, Jr., Network for Lifeline Simulation Experimentation. If we can design stronger, more reliable systems for our municipal conveyance of water, gas, and power, we'll go a long way in protecting our nation. Industrial companies also have interest in this, for both on and off shore technologies. If we can develop smart pipelines and equipment to monitor these, then again this will strengthen our lifeline system.
As a teaching and research university, we also have strong ties to other universities within the NEES community. Our partners are Rensselaer Polytech-- RPI-- in Troy, who operate a geotechnical centrifuge. This geotechnical centrifuge will be used to extend the kinds of experimental and analytical simulations that we can do in lifelines. We also have a strong outreach program in education.
We've partnered with our local discovery science museum, the Science Center, here in Ithaca, New York, to develop K through 12 outreach programs that will reach thousands of youngsters, as well as their parents and grandparents, and inform them of the importance of lifelines to our way of life.
So we're proud to be part of this George E. brown, Jr., Network for Earthquake Engineering Simulation. We believe that we will continue to perform research, education and outreach, and develop new frontiers in civil infrastructure research. Thanks very much, and now back to you at NSF, Ian.
SPEAKER 1: Excellent demonstration. I might say to those who are watching that it looks simple to do something like that, but there are all kinds of logistics problems, not the least being what do you do with the sand after the event? And so what you don't see is part of the cost of the insulation that Cornell, with all the soil handling equipment, to be able to fill those boxes and of course empty them afterwards.
It is a non-trivial exercise working with large scale geotechnical experiments. I might also say that think of getting rid of that column [INAUDIBLE]. Just the demolition costs of some of the large scale structural experiments is a significant item. Cornell is one of three geotechnical sites, as I have already said, the only one with an articulated box for studying buried lifelines. The other two geotechnical sites have large geotechnical centrifuges.
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The George Winter Laboratory, home for a National Science Foundation (NSF)-funded project to establish the nation's premier center for large-scale earthquake simulation experiments, had its public debut on Nov. 15, 2004 with an NSF-sponsored live webcast of an experiment designed to study the deformation and rupturing of underground pipelines during an earthquake -- "lifelines" that can carry, for example, water, natural gas, liquid fuel or telecommunications.
The experiment was explained by the earthquake facility's director, Harry Stewart, an associate professor in the School of Civil and Environmental Engineering (CEE), and by Tim Bond, manager of technical services at Winter Lab. The co-principal investigator for the project is Thomas O'Rourke, the Thomas R. Briggs professor of CEE.
As part of the national Network for Earthquake Engineering Simulation system (NEES), the lab will provide new information about the effect of major earth movements on pipelines "and lead to new construction practices that will enable the lifelines to survive even under the massive forces that earthquakes can generate.