My Bridge

Building a bridge has been an extremely difficult task so far. Even getting the materials to get started was hard because I had to get the exact dimensions for the wood. There is also a lot of thing to take into consideration when building a bridge. I have to make sure it stays under the weight limit, but also that it can hold 120 pounds. I have to make sure my bridge stays in static equilibrium so that it does not collapse under the weight and pressure. 

In order to make my bridge the best that it can be, I am going to build several different types of bridges including a truss bridge and an arch bridge. I am going to try to build a bridge with a warren truss because it has a special way of distributing the force. Where the force and pressure of the load is put is extremely important when building a bridge. Otherwise, if it goes to the wrong place, the bridge will completely collapse. 

The problem with building an arched bridge is that you have to heat the wood up a little bit. Also, once the wood dries, it stays in that shape. 

In our group, we have decided to split up and work on different types of bridges. Then we will regroup and see what works best. We are also giving each other tips on how to build the bridge along the way. 

Building a bridge is a tough, time consuming project. However, I will try my best and hopefully it will be able to withstand 120 pounds using the techniques I am researching. 

Static Equilibrium

When all the forces that act upon an object are balanced, then the object is said to be in a state of equilibrium. Even though these forces are balanced, it does not mean that they are equal. Objects in equilibrium have a net force and acceleration of zero. This comes from Newton's First Law of Motion. 

Even though the object has an acceleration of zero, it does not mean that it is at rest. It can also mean that the object is in motion and continuing in motion with the same speed and direction. 

However, when an object is at rest and is in equilibrium, it is said to be in "static equilibrium". Static means stationary or at rest. 

A bridge is an example of a system in static equilibrium. The bridge undergoes no motion. Static equilibrium is an important concept when building a bridge whether it is small or huge. It is important because these structures need to maintain static equilibrium under all expected loading conditions. A bridge reaches static equilibrium when the weight on top is equal to the resistance on the bottom of the bridge. If the bridge was not in static equilibrium, then it would not be able to hold all the weight it was supposed to, and it would collapse. 

Bridges

A bridge is a structure built to span obstacles such as bodies of water, valleys, or roads to provide passages over the obstacle. There are many different designs of bridges that serve unique purposes and apply to different situations. Designs of bridges differ depending on the function of the bridge, the nature of the terrain, the material used to make it, and the funds available to build it.

The first bridges were made by nature itself. These "bridges" were often trees fallen over that provided a passage across a stream or small river. The greatest bridge builders were the Ancient Romans. They built arch bridges and aqueducts that withstood extreme conditions. Many other civilizations caught on and began to build different types of bridges.

Types of Bridges:

Beam Bridge: horizontal beams that are supported at each end by substructure units. The earliest beam bridges were just simply logs across rivers and other similar simple things. Beam Bridges are the most common bridge type in use today. 

Truss Bridge: A bridge whose load-bearing superstructure is composed of a truss. This truss is formed by triangles. Truss bridges are one of the oldest types of modern bridges. A truss bridge is economical to construct owing to its efficient use of materials.

Cantilever Bridge: They are built using cantilevers-horizontal beams supported only on one side. They are constructed using much of the same materials and techniques as a beam bridge; however, there is a difference in where the forces act. 

Arch Bridge: Arch bridges look slightly like beam bridges; however, they have abutments at each end in which the weight of the bridge is thrust into. Abutments are substructures at the ends of bridges where the bridge's superstructure rests. 

Tied Arch Bridge: They have an arch-shaped superstructure but the ends of the arches are restrained by tension in the bottom of the structure. They are also called bowstring arches. 

Suspension Bridge: They are suspended by cables. In modern suspension bridges, the cables hang from towers that are attached to caissons or cofferdams. 

Cable-stayed Bridge: They are also held by cables. However, there is less cable required to build these and they also tend to be higher. 

Most bridges are fixed bridges, but you can also find movable bridges that having moving parts to it. There are also double decked bridges with two levels to support more traffic. These tend to be in busier areas such as large cities.