The following is a material list, description and illustrative photos on how to construct an affordable shake table for earthquake simulation. The materials are all available at local hardware and lumber supply stores at a cost of about $13. The time required to assembe is approximately 30 - 45 minutes.
This shake table can be assembled by the students themselves or prior to class in order to save time.
Earthquake Engineering Component
Structural earthquake engineering is an iterative process that strives to improve structural response to earthquake-induced forces. Earthquakes can cause walls to crack, foundations to move or settle, utilities to rupture and even entire buildings to collapse. In an effort to protect the public and avoid structural damage engineers incorporate into their structural designs techniques that withstand these incredible forces. Shake tables are often utilized by engineers to simulate the destructive ground accelerations that an earthquake inflicts on structures.
Learning Objectives and Standards
Links to the National Science Standards and to individual State Science Standards are available by using this link:
(This shake table design was retrieved from www.discoveryeducation.com)
- 2 ft. x 2 ft. plywood (or other wood as available, recommend 1/4– 1/2 inch thick)
- 2 1/2 inch to 5/8 inch diameter wood dowels, approximately 36 inches long (note: hard woods are more durable, especially if the table is used for heavier items, i.e. liquefaction demos.)
- 1 inch x 10 ft. PVC schedule 40 pipe that will be cut into 2 – 24 inch pipes and 2 – 30 inch pipes.
- 4 – 1 inch PVC schedule 40, 90 degree elbows
- 4 1/4; inch x 2.5 inch eye bolts with corresponding 1/4 inch nuts
- 4 1/4 inch x 1 inch hex bolts with 1/4 inch nuts (Note: hex bolts may be longer or shorter depending on the thickness of the 2 ft. x 2 ft. board utilized.)
- 4 – rubber bands (recommend #64 bands)
- Velcro strips (or other material to hold the structure to the shake table surface)
Construct the shake table (this process takes about 1/2 hour):
- Cut the PVC pipes into 2 – 30 inch and 2 – 24 inch pipes. Drill 5/16 inch holes 2 inches from each end of the 24 inch pipe sections. Join the pipes with the PVC elbows forming a rectangle.
- Insert the eye bolts into the drilled holes on the 24 inch PVC pipes and fasten with the 1/4 inch nuts.
- Drill 5/16 inch holes in the four corners of the 2 ft. x 2 ft. plywood. Center the holes 2 inches from each edge. Insert the 1/4 inch hex bolts and corresponding nuts in these holes and fasten. Leave some play so that the rubber bands can be wrapped around the bolts.
- Place the dowels on top of and perpendicular to the 30 inch PVC pipes. Place the plywood on top of the dowels. Wrap one rubber band around each eye bolt and then around the hex bolt nearest it. Now tighten the hex bolt to a snug fit securing the rubber bands in place.
- Place the Velcro on the plywood in a configuration such that it is able to hold your structure securely on top during the shaking activity.
Links and Resources
- NEES Academy: http://nees.org/education/for-teachers/k12-teachers
- Teach Engineering: http://teachengineering.com
- This shake table design is stable and large enough to accommodate a number of different structures or soil containers for a variety of lessons. The shaking motion can be implemented into a diverse number of lesson topics, as well, such as forces, acceleration, friction, frequency and period, etc.
- Please refer to lesson plans posted on nees.org/education for possible uses of this shake table.
Researchers should cite this work as follows:
Jason Lloyd; NEES EOT (2011), "NEES Teaching Demonstration: Shake Table Assembly," http://nees.org/resources/2938.