‘Construction’ Category

Heavy Lift Crane

Photo Credit: Alex Mead

Seen here on the left hand side of the picture above is a heavy lift crane hoisting large steel frames from the position on the ground where they were assembled onto the top lip of California Stadium in Berkeley, California. These steel frames eventually became the luxury and press boxes of the renovated stadium. Using heavy lift cranes comes at a high cost due to several reasons, one being that the crane must be trucked to the site in many pieces and assembled specifically for the lift. Often the assembly alone requires several smaller cranes in itself. As such, designers and construction workers try to make structures that can be built without the use of this type of specialized equipment. The tradeoff here making it worth the use, however, was that steel workers were able to build the frames on the ground leading to benefits that outweighed the cost and hassle of using a heavy lift crane.

Crane Barge – Left Coast Lifter

Photo Credit: Alex Mead

Pictured above is a custom built crane barge called the Left Coast Lifter. It was originally built to assist in the construction of the Bay Bridge East Span replacement connecting Oakland, California and San Francisco, California. The Bay Bridge East span project was completed in September 2013 and the Left Coast Lifter was transported via the Panama Canal to New York State for use on the replacement Tappan Zee Bridge project over the Hudson River.

Concrete Pouring Boom

Photo Credit: Alex Mead

Seen here is a concrete placement boom. The boom is basically a small crane type structure to help hold a pipe filled with concrete with the goal of making the placement of concrete easier. The end of the pipe which is visible in the picture is being controlled by two workers, one in orange and one in florescent yellow, and is depositing concrete in the form work for a large mat foundation. The other end of the pipe is connected to a concrete pump, perhaps in a concrete pumper truck or a stand along pump. These types of booms in various types and configurations are common in large concrete pours.

Viaduto do Corgo Bridge, Portugal

Photo Credit: Cl√°udio Venceslau Ferreira

Seen here is the Viaduto do Corgo bridge project in the Vila Real region of Portugal. The photo is of over two dozen bridge piers being constructed for a large car and truck bridge. Specifically one can see two slip-form carriages riding up piers and tower cranes built alongside these piers to aid in their construction. Projects like this require many people to work on them, ranging from politicians to get money for the project, to engineers to design the project, to construction works to build the project. In most cases these large scale construction projects employ many thousands of people over the course of years and can stimulate the local economy with the massive influx of works and materials for the bridge.

Spread Footing Foundation

Photo Credit: Alex Mead

Seen here are three rebar cages for the spread footings of a large building. Spread footing foundations are preferred to deep foundations. This is due to the increased work, and therefore increased cost, of a deep foundation. Deep foundations could use H-piles, micro-piles, or other options to support the building. For the design of a foundation, the bearing capacity of the soil or rock and the column loads of the proposed building must be understood. If the size of the footing can be made feasibly, given the loads and bearing capacity of the project, spread footings will be used.

Building Demolition

Photo Credit: Alex Mead

Seen here is the demolition of Campbell Hall on The University of California – Berkeley campus. Three machines are being used for this activity: a man lift, a traditional excavator, and an ultra high demolition excavator. Demolition of a building in this setting is high risk due to the possibility of debris falling out of the site boundaries. In order to minimize this possibility, great care is taken by the operator of the ultra high demolition excavator. Also, dust generated by the demolition is unacceptable in an environment like a college campus. Therefore on this project three fire hoses are used from varying angles to keep the dust in control.

Winter Construction – Mat Foundation

Photo Credit: Alex Mead

This picture illustrates many lessons for actual construction and also gives a perspective of the actual scales necessary for use in even moderate size concrete construction. To begin, it is clear the snow on the ground and in the air means the temperature is below freezing, single degree Fahrenheit temperatures to be specific. This means workers will be slower and must take more frequent breaks to warm their bodies. Also, the construction site is slippery and objects become covered in snow leading to increase fall and trip hazards. One final interesting fact is the size of the rebar cage the workers are building. Notice how the workers are standing fully upright in a volume that will be filled completely with concrete. This mat-foundation job was poured in several pours ranging from 2 000 to 6 000 yards in size.

Concrete Formwork

Photo Credit: Alex Mead

Seen here is concrete formwork that has just arrived on a construction site and is ready for use. These flat formwork pieces are used for things like walls or elevated slabs, where a flat surface will be needed. Form pieces like this are fairly straight forward to build, however, require some space and are best constructed in an assembly line type method. However, space on many projects, like this underground parking structure, is at an absolute premium. Thus, many times these types of formwork pieces are constructed off site at a location with “cheap” space. In the construction industry this space at which a company does off site work is commonly referred to as “the shop.”

Jackhammer Attachment on Tractor

Photo Credit: Alex Mead

Seen above is a tractor with a jackhammer attachment on its boom. This type of setup is common for small road construction jobs throughout the United States where portability and more power than a simple hand held unit can provide are needed. This jackhammer is breaking up the concrete around an old manhole cover that is being replaced.