Research

Rubble-House Research Project

Dr. Adam Kaplan initiated a research project on rubble houses with a team of faculty from the Surveying and Mapping, Civil Engineering, and Construction Management programs, and conducted full-scale static load testing on a rubble house on campus.

 

 

 

 

 

News coverage during the construction stage.

A typical CMU wall being tested with a 120 lbs concrete battering ram.

A rubble-wall being tested with a 120 lbs concrete battering ram. 

 

In January 2010, a devastating earthquake in Haiti destroyed several concrete and masonry structures, killed over 200,000 people, and displaced thousands of families. As part of the relief effort, non-profit organizations in the United States have built replacement homes in areas severely impacted by the earthquake. Given the abundance of post-earthquake rubble, the idea of a house built with walls made of welded wire baskets filled with loose rubble emerged as a cheap and quick solution for the poor. Conscience International, Inc. (CI) of Georgia used a unique construction technique to build more than 70 rubble houses in the last two years. KSU and CI launched a preliminary research effort in August 2011 to assess the current construction method and seismic resistance of rubble houses. The project began with limited sponsorship from both KSU and CI and relied heavily on donations and volunteers. A full-scale (14 ft. wide, 20 ft. long, and 8 ft. tall) rubble house was built in the middle of KSU-Marietta campus and subjected to static load testing in order to increase exposure to the University community and promote student involvement. Over 1200 hours of engineering and non-engineering student labor time were spent on planning, construction, and testing. The project increased students' awareness of community issues while also encouraging team-based learning and interdisciplinary collaboration.

The team presented their findings at local meetings of the American Society of Civil Engineers (ASCE) and the Surveying and Mapping Society of Georgia in January 2012. (SAMSOG). They also tested a small-scale replica of the wall on a seismic shake table at ATS in February (Applied Technical Services). The project was presented at the American Society of Civil Engineers (ASCE) and American Society for Engineering Education (ASEE) conferences in June 2012. The research and development efforts are ongoing.

Please visit http://engineering.kennesaw.edu/rubblehouse/index.php for more information. 

Seismic Interface Stability of Composite Dams

The main problem in evaluating the seismic stability of a composite dam, among other things, is the dynamic interaction between the concrete gravity dam and the soil embankment. The wrap-around sections of a dam are the transitional sections where the dam transitions from a concrete dam to embankment wing dams. The disastrous consequences of a dam failure provide incentives for a thorough examination of the issue. During strong earthquake shaking, the soil may slip and/or separate (debond) from the concrete surface, and upon reversal of motion, the soil may reattach (rebond) to the concrete surface. Water enters the gap created during the process when the upstream surface debonds, and water is expelled when the gap rebonds. Repeated debonding-rebonding can cause a permanent gap due to plastic embankment deformation, internal erosion due to water pumping action, and dam failure.

The results of the analysis indicate the possibility of interface separation, acceleration amplification, and high pressure, which could cause dam distress or failure, and the problem requires immediate research attention. There are 36 concrete dams with wing dams in countries other than the United States, according to the list of The World's Major Dams and Hydroplants. In the United States alone, there are more than 40 dams with composite sections that are higher than 100 feet and are located in seismically active areas.

Impact Analysis of Road Side Barriers and Seismic Analysis of MSE Walls and Bridge Abutments

Retaining walls typically have safety rails top-mounted on them, and vehicles that crash into these can seriously harm the walls. In addition to improving safety, the new design guidelines aim to reduce serious damage to rails and supporting retaining walls so that the rail-wall system may be repaired and/or reset with the least amount of effort and expense.

An estimated half of all retaining walls for transportation applications—more than 7,500,000 square feet—of MSE walls with precast panel facings are built each year in the United States. Over 2,000,000 square feet of these walls contain modular concrete block facings, which are by definition weaker than the reinforced concrete wall facings in hybrid walls. Top-mounted traffic barrier rails are fixed monolithically to continuous footings to prevent severe wall damage during vehicle collisions (named anchor slab, moment slab, or sleeper slab).

The efforts made in this study's numerical analysis have served as the foundation for work in various fields, including the seismic analysis of hybrid walls, MSE retaining walls, and bridge abutments.

Performance of Earth Dams under Strong Earthquakes

Strong ground shaking may cause substantial suffering to tailing dams and earth dams. Large plastic deformations and strength losses brought on by the liquefaction of loose granular fill could cause enormous water-retaining structures to break disastrously. Such structures require finite element (FE) analysis, which calls for the use of robust software and computers. To confirm the dependability of the computer program, the results of any given software's computer analysis must be compared with those of another similar software.

The goal of this study was to use various FE computer programs to perform a liquefaction analysis on the Butt Valley Dam, which is owned and controlled by PG&E and is situated in California.

Cost of Winter Sanding

This is the first collaborative study between the Colorado Department of Transportation and the Colorado auto insurance industry to address the cost issues associated with the use of sand as a roadway traction enhancement material in inclement winter weather. Sand was traditionally spread on snowy and/or icy pavement to improve traction. This has been shown to be costly in a variety of ways, including roadway maintenance, vehicle damage (particularly to windshields), and environmental and human health consequences. The total cost of windshield damage has been increasing at a rate of $6.19 million per year. Windshield damage in the state of Colorado is estimated to be around $90 million before inflation. The statistics appear to show that the rate of increase is slowing at a time when the state population is growing at an exponential rate, as is the number of auto insurance policies.

The mechanism of airborne particles was investigated in this study through field tests using a high-speed camera and FE computer simulations. When tires roll over sand particles, elastic energy is stored in both the particles and the asphalt pavement. Sand particles are bounced into the air when the tire-pavement interface pressure is released, gaining more speed when hit by moving vehicles and reaching higher elevation.