Title of Exploration


Abstract: A brief description of the exploration.
Subject Author Replies Views Last Message
Halfway Point pasquinit pasquinit 0 27 Nov 29, 2009 by pasquinit pasquinit
flood-resistant homes BrandonChalifoux BrandonChalifoux 6 109 Nov 23, 2009 by Jender Jender

Problem or Need Statement

We are trying to determine which style home will best prevent structural damage from the force of water in a flash flood. We are measuring 'best' by three characteristics:
1. is the home structurally stable when water passes through quickly (as though the home is on a hill)?
2. is the home structurally stable when water is present for an extended period (as though the home is in a valley)?
3. are the materials used to build the home cost effective?

State of the Art

The most common design techniques for preventing structural damage from a flood are:
-raising a house on stilts
-building a home on a hollow concrete foundation that will float
-making a home completely watertight
-channeling the water away from the home
-allowing water into a resiliant lower flooor that is easily drained

For the sake of our experiment we want a home that will structurally withstand the floodwaters, so we do not want to use a house that will float. Also, it is hard for us to make a model home completely watertight because that requires using sealants and extra materials. Again, while channeling the water away from the home seems to be a good solution, it is not a structural design on the home itself.

Specifications and Metrics for the Solution

To measure the force of moving water we will use the equation:
force = density * (volume / change in time) * velocity
To measure the force of static water we will use the equation:
pressure = density * gravity * depth
force = (1/2) density * gravity * depth * drag coefficient * area

Brainstorm Alternative Solutions

A solution we came up with is building a semi-circle wall around the frontside of the house that will redirect the water away from the walls of the home.

Identify Priority Alternatives/Implementations

House with stilts: The pro's of a house with stilts is that one, the water would flow around the house, causing little or no damage to the house itself. Two, a house with stilts would cost ___. Some cons about the house with stilts is that level ground is needed in order to build a sturdy home on top of stilts.
Home with ventalated basement: A home with a ventalated basement has many pros. One is the look of the house would not need to be altered. The basement is the bottom part which is the only aspect of the house that needs modifying. Two, an open bottom basement wil allow for the water to rush under the house and will take away force on the bottom of the house.
House with wall:


Implement Solution and Test

What we are doing to creat this simulation is we are building a total of seven houses with difference between them. We are having a one foot slope with three types of houses on it. There will be a house on stilts, a house with a ventalated bottom, and a house with a wall. This part of the experament will show the effects of a flood with rushing waters. Then there will be a one foot base at the bottom which will also have the same three types of house designs. This part will however show the effects of sittting flood waters. Each of our houses will be 4x4x5in. All houses will be made out of foamcore board. All of the modifications of these houses, i.e. stilts vented bottom, and wall, will be made from metal. Each modification will be two inches. There will also be one control house with no modifications that will show a regular house design with no flood added modifications. This house ill also be 4x4x5in.

Data/Analysis

Calculations

calculations.JPG

calculations2.JPG

house_collage.JPG

Graphs

The following graphs were made to show the force needed to cause structural damage to each of the four designs of flood-resistant homes.
2.JPG
Above: Control House
The control house experienced damage when under the force of less than 20N. Clearly, this was not a flood resistant home because our calculations said that the force of a typical flash flood to scale would be approximately 32.8N. Under the force of a typical flash flood, a home like our control house would predictably have major structural damage.
3.JPG
Above: Home with Semi-Circle Wall
According to our data, the home with a metal semi-circle wall in the front, took a lot of force to destroy. It handled multiple hits of over 60N of force before even beggining to show signs of structural damage to the home. In our experiment, this home was the most structurally stable after the force of a flash flood, and thus we would deem it the most flood resistant home.
4.JPG
Above: Home with Grate Bottom
The home with the grate bottom allowed water to pass through really well in our video under the faucet, and it required over 40N of force to cause structural damage to the home. Since our calculations said a typical flash flood to scale would have a force of about 32.8N, this home would probably resist damage from most flash floods. However, it was not quite as strong as the home with the semi-circle wall.


1.JPG
Above: Home with the Stilts
The home also did well allowing water to pass under the faucet. However, when using the force probe, the house fell to the ground after only a few seconds. In those 3 seconds, the force was over 60N, so it would most likely resist a typical flash flood. We can also assume that the home on stilts went down more quickly due to poor construction, and probably would be better constructed than the ones we made.

Videos:





FINAL ANALYSIS:

From our data and analysis, we have concluded that the home with the semi-circle wall in front is the most effective in flood resistance. It took an immense force to cause structural damage to the wall, and even more force to damage the house. Although we did not get the chance to look into the possible expenses of such a structure, we narrowed our experiment to only look at the resistance of a flash flood force. The house with the semi-circle wall performed the best in this area, so we conclude it is the best option.

Conclusion


We found that the best flood resistant home design was a house with a semi-circle wall in the front. This home fulfilled our problem of staying structurally stable after experiencing the force of a flash flood. We found that a flash flood to scale would have a force of 32.8N and this house did not show signs of structural damage until over 60N were applied. If we had to redo the project, all we would change is to have more time. Our project was very complex because we had to design our own experiment, which required us to briefly learn about water dynamics. Furthermore, we had to construct a huge model in order to collect data. Due to all of these requirements, we did not have time to research the cost of the materials that would be used to make the modification structures in real life. We also did not have time to measure the affects water would have on homes after sitting for an extended period of time. As a result, we could only base our 'best' flood resistant home off of one factor, rather than multiple. In the long run though, we learned a lot not only about architectural design, but about floods, and water dynamics. Not too mention, we had a blast destroying our model homes! We really enjoyed this project!

Sources

www.wikipedia.org/physics

Acknowledgments

Thank You:
Brandon Chalifoux
Dr. Pasquini



Additional information on these sections can be found on the inquiry model page.