The wall was put to test recently by engineers at the UC San Diego Englekirk Structural Engineering Center, which has the largest outdoor shake table in the United States. During the first series of tests, led by Dawn Cheng, a UCSD engineering alumna and now a civil engineering professor at UC Davis, researchers investigated the seismic response of a semi-gravity reinforced concrete cantilever wall.
California has thousands of miles of these types of retaining walls on highways, roads, bridges and oceanside bluffs that have withstood earthquakes in the past. However, the seismic design of these walls has not been extensively developed. The outcome of this research, funded by Caltrans, will ensure that future retaining wall systems are designed to a higher performance standard and existing systems are upgraded and retrofitted to offer satisfactory performance to provide a safe and mobile transportation system in California.
Retaining walls – mostly made of concrete and steel – are normally used to support traffic loads and to create more of an abrupt change in elevation than a slope typically can. The main objective is trying to come up with a better understanding by observing how these structures behave and what kind of failure we can expect during an earthquake and to obtain some of the performance data so we can come up with better analytical models and design guideline methodologies,” Cheng said. “We also want to look at the behavior of the structure when the soil is interacting with the system under earthquake shaking.”
“A lot of the sound walls are connected to the retailing walls. The design of that is critical because you are handling a bigger structure. The behavior is different,” she said. “A lot of the retaining walls are supporting the sound walls in the field on the highways and overpasses. The performance under a dynamic earthquake is different when you have a sound wall on top because of the additional mass that changes the weight and stiffness of the system. In an earthquake you have to take that into account during the design process.”
This project is unique, Cheng said, because it is the first comprehensive system level earthquake simulation test of a full-scale interactive soil-retaining wall structure supporting a sound wall.
“UC San Diego has one of largest and most unique testing facilities in the world,” she said. “The Englekirk Center has all the state-of-the-art testing facilities and there is a lot of technical support. The other reason this site was unique is because it has a large Caltrans funded laminar soil box and a soil pit on the site. UCSD is also the place where I did my Ph.D. research".
The research performed by Cheng and her colleagues will give Caltrans the opportunity to check its current retaining wall designs and input any necessary changes, according to Kathryn Griswell, ERS Specialist for Caltrans’ Office of Design & Technical Services. “This is a brand new modification and it’s time to find out how it behaves under an earthquake,” Griswell said. “These types of walls rarely fall down and cause hazards or loss of lives or other safety issues. Normally what we have to deal with are maintenance issues and costly repairs from earthquakes, so we’re looking to modify the designs whenever necessary to keep costs down.”
Andrea Siedsma | EurekAlert!
Smart homes will “LISTEN” to your voice
17.01.2017 | EML European Media Laboratory GmbH
Designing Architecture with Solar Building Envelopes
16.01.2017 | Fraunhofer-Institut für Solare Energiesysteme ISE
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
19.01.2017 | Earth Sciences
19.01.2017 | Life Sciences
19.01.2017 | Physics and Astronomy