Monday, February 28, 2011

#13 Fire Hydrant

Description:  Above is an example of the harsh conditions civil infrastructure must endure in northern states and places where long winter climates are a fact of life.  As you can see the entire outside of this fire hydrant is covered in a layer ice! Ice is incredibly strong at prying apart seems, spreading cracks, and generally reeking havoc on anything man made.  Civil engineering infrastructure that is designed for northern climates must be made to handle forces such as those presented by ice.

Saturday, February 26, 2011

#12 Medium Sized Dam featuring Sluice Gates

Description: The dam pictured above is one of thousands of such dams spread across the United States.  This dam is used to control the flow of water downstream by limiting the flow of the river over itself.  Water volume is regulated by raising and lowering steel doors, called sluice gates, on top of the dam.  During normal conditions this dam operates with two sluice gates partially open, but during flooding more gates can be opened to allow more water to pass.  It is very important that too much water doesn’t build up behind the dam which could lead to dam failure. 

Thursday, February 24, 2011

#11 Cone-Penetration-Test (CPT) Rig

Description: Pictured above is a Cone-Penetration-Test(CPT) Rig. CPTs are used for geotechnical site-investigations and can help determine the soil type, soil layer thickness, relative strength of the soil, and pore water pressure, among other things.  This information is then used to determine how structures must be built on the site. The CPT test is done using a small diameter cone that is hydraulically pushed at a constant displacement; the cone is configured with multiple transducers to measure tip resistance, sleeve (friction) resistance, and pore-water pressure. 

Tuesday, February 22, 2011

#10 Steel in Reinforced Concrete - Construction

Description: What you are looking at is the steel that is in all the reinforced concrete structures around you.  The large number of bars that you see are meant to hold the tension force in the foundation of this underground parking structure.  One of the main costs in reinforced concrete construction is the labor to place all the resteel where it is needed.  As you can see from this photo the number of resteel bars is staggering.  Rest assured though, each bar has its proper place calculated by a competent structural engineer!

Sunday, February 20, 2011

#9 Steel Rail Road Bridge

Description:  This is a steel rail road bridge over the Huron River in Ann Arbor, Michigan.  It has concrete piers which are typical for bridges of this type.  Concrete is very resilient, strong in compression, widely available throughout the world, and relatively affordable.  For these reasons concrete is used for many civil engineering applications.

Friday, February 18, 2011

#8 Cell Phone Towers in Urban Environments

Description:  So this may appear to be just another building, and it is.  What’s unique about this picture, however, is the group of white vertical bars near the top of the building.  Those vertical bars are actually antennas used for cell phones.  Most people don’t notice them, but if you start to look around these antennas are on a surprising amount of buildings in urban environments.

Wednesday, February 16, 2011

#7 Coal Ash Impoundment Pond

Description: Pictured above is a coal ash impoundment pond.  Coal ash, a result from the combustion of coal in power-plants, is typically impounded in such ponds because the ash can be mixed with water into a slurry and pumped from the power-plant to the pond for extremely convenient handling.  When deposited in the pond the ash will settle to the bottom and the water will be removed from the top and treated.  Coal ash, classified as fly ash, bottom ash or boiler slag, depending on what part of the process the ash comes from is frequently disposed of in impoundment ponds.  Exact disposal methods, however, are ultimately dependent on the state environmental code.

Monday, February 14, 2011

#6 Brick Road

Description:  Featured above is a brick road.  Common throughout the world before the large spread use of concrete and asphalt, they can still be seem in many cities, kept as reminders of the past.  Requiring large amounts of labor to construct and maintain, brick roads are rarely built today.

Saturday, February 12, 2011

#5 Fish Ladder

Description:  This is a fish ladder.  It is used in conjunction with dams and weirs to allow migratory fish to pass around the main falls of the dam.  It consists of small steps of waterfalls, one right after each other, so fish can make the jump from level to level getting up around the dam to continue their swim upstream.  Without fish ladders many migratory fish couldn’t go up stream for spawning and the fish population would undoubtedly suffer.

Thursday, February 10, 2011

#4 Scaffolding for Building Repair

Description: Featured in this picture is a complicated erection of scaffolding.  Scaffolding configurations like this, and far more complicated systems, are used to gain access to the entire outside of buildings for renovation and repair purposes.  In this photograph it can be seen that the outside of this church is being refinished for architectural reasons.  The advantage of using scaffolding over a cherry picker or other means of access is the ability to have many workers at different parts of the structure at the same time.  Scaffolding also allows for waves of work to move up or down the structure concurrently as is common with many construction schedules.  If you look close you can see workers near the top of the steeple!

Tuesday, February 8, 2011

#3 Foundation Excavation

Description:  So what is that guy doing so close to that excavator?  He is measuring how deep the hole is to make sure the foundation is built to the proper dimensions called out in the plans.  When digging a hole for a foundation it is crucial that the footings, piles, and foundation walls are built to the proper size.  By using a pole with a sensor on it, the worker is able to guide the excavator operator to dig the exact depth needed.  Typically the pole will have a sensor on it that picks up a laser beam being emitted at the proper height. The sensor beeps when it is level with the laser and thus the bottom of the pole is at the proper depth of excavation.  This method of hole depth measuring allows rough digging of the foundation to be done with machines. Workers can then finish the hole by hand to the more exact dimensions needed for the future building.

Sunday, February 6, 2011

#2 Crumbling Infrastructure

Description: A perfect example of the crumbling infrastructure we all hear about in the media.  The problem with this bridge pier is obvious to any civil engineer, but may be not understood from a simple look.  The problem is the fact that the reinforcing steel (rebar) is exposed to the elements and is rusting.  The rebar takes all tension loads, prevents shrinkage of the concrete, and provides shear resistance.  When the rebar rusts strength is lost and the ability of the bridge pier to perform its job in supporting to above roadway is compromised.

#1 Broad Crested Weir

Description: The Sixth Street Dam, or more properly the Sixth Street Broad Crested Weir, is located near downtown Grand Rapids, Michigan on the Grand River.  It was constructed originally to power furniture mills but currently has no direct application.  Typically, there is a six to eight foot vertical drop from crest to the downstream water surface but in flood conditions this can be reduced to only two or three.  The Sixth Street Dam is also fitted with a fish ladder to allow migratory fish, like salmon and steelhead, to pass and continue up stream.