Related Links

• Science Fair Project Guide

Project Summary

Difficulty	6
Time required	Average (about one week)
Material Availability	Readily available
Cost	Low ($20 - $50)

Donate to Science Buddies

Sponsor

Sponsored by a generous grant from Chevron

Free Simulation Game Build your city, choose its energy options, see what happens next.

www.willyoujoinus.com

Objective

The objective of this project is to determine what effect additives have on the transfer of force through saturated soil. The reason I performed this investigation was to try to establish if the effects of liquefaction can be prevented or lessened by adding elements to the soil.

Introduction

In locations with high earthquake potential, the susceptibility of the existing soil to liquefaction can pose problems for building. Is it possible to add elements to the soil to help minimize the effects of liquefaction on sandy soils?

Terms, Concepts and Questions to Start Background Research

In order to properly conduct this experiment, you will need to understand soil liquefaction. What conditions need to be present for soil liquefaction to occur? What causes soil liquefaction? What methods are currently being used to mitigate liquefaction hazards?

You should also develop a good understanding of soil types from an engineering perspective, i.e. what makes for a "solid" soil vs. a less stable soil given the potential force of an earthquake. How will your "additives" impact the structure of the soil?

Bibliography

The Soil Liquefaction Web Site from the University of Washington offers a great introduction to liquefaction:

http://www.ce.washington.edu/~liquefaction/html/main.html

The US Geological Survey web site also has some general information on earthquakes and liquefaction that is written specifically for students grades 7-12:

http://earthquake.usgs.gov/4kids/

In 1998 NASA conducted a study on the Mechanics of Granular Materials. They actually took columns of sand and sent them into space so they could further investigate the behaviors of granular materials without the stresses of gravity. The structure of the experiment is similar to the experiment that is being tested here, and offers some good general information and findings on the structure of granular materials and liquefaction.

http://science.nasa.gov/newhome/headlines/msad06jan98_1.htm

Materials and Equipment

• Section of PVC pipe
• Drill
• Sandy soil
• Experimental Fillers: bark, dried leaves, polymers, and Styrofoam popcorn
• Water
• Dowels
• Weights
• Mosquito netting or cheesecloth
• Duct tape
• Force-measuring device (such as a spring-scale)
• Shake table (optional)

Experimental Procedure

1. Drill four holes in the PVC pipe. The holes should be equally spaced vertically and should be sized to fit the dowels that you will be using in the experiment.
2. Cover the bottom of the pipe with the mosquito netting or cheesecloth, which will allow water to seep in while keeping the soil n the pipe.
3. Fill the pipe with soil.
4. Saturate the soil with water by placing the bottom of the pipe in a container filled with water and letting the water seep into the pipe from the bottom. You will probably need to leave the pipe in the water overnight to give it time to fully saturate. Make sure you use the same amount of water each time.
5. Once the soil is saturated, seal the bottom of the pipe with duct tape to keep the soil and water from seeping out.
6. Quickly insert the four dowels into the holes.
7. Place weights on the soil at the top of the pipe.
8. Wait at least one hour for the soil to settle. To assist the settling of the soil, tap the pipe lightly two to three times.
9. Drop the pipe three times on a hard surface from a height of approximately two inches to simulate an earthquake. Alternatively, if you have access to a shake table, this could also be used to simulate the effects of an earthquake. If using a shake table, you will need to make sure that the pipe remains vertical while on the shake table.
10. Pull out the dowels using a force-measuring device to determine the level of contact forces in the soil.
11. Repeat steps 3-10 combining the additives (bark, dried leaves, polymers, and Styrofoam popcorn) one at a time to the soil to test the ability of each of the additives to reduce the effects of liquefaction.

Variations

• For more science project ideas in this area of science, see Geology Project Ideas.

Credits

Marie E. Jenkins

Last edit date: 2005-08-31 13:55:52

Career Focus

If you like this project, you might want to think about career opportunities in Geology.

Just as a doctor uses tools and techniques, like x-rays and stethoscopes, to look inside the human body, geoscientists explore deep inside a much bigger patient—planet Earth. Geoscientists seek to better understand our planet, and to discover natural resources, like water, minerals, and petroleum oil, which are used in everything from shoes, fabrics, roads, roofs, and lotions to fertilizers, food packaging, ink, roads, and CD’s. The work of geoscientists affects everyone and everything. Learn more about this career: Geoscientist.