The construction of the World Trade Center is facing some significant challenges due to its complex design by Santiago Calatrava. The main structure is over 365 feet long and includes more than 11,000 tons of structural steel. One of the most challenging situation is because of the geometry proposed and the amount of welding required to complete the installation of the massive steel structure. The entire structure was modeled to determine a carefully staged erection sequence. The hub is scheduled to open some time next year. The cost of the project has almost doubled from its original estimate to nearly $4 billion. Calatrava's design is intended to evoke a white dove taking flight.
However, this amazing transportation hub could face some competitors as a new design has been unveiled for the point in the Woodside section of Queens where the number 7 subway line and the Long Island Railroad meet. Designers Chad Kellogg and Matt Bowles of AMLGM have named the project The Urban Alloy Towers, which they see as a mixed-use structure that combines the transit hub with retail and housing.
Photo Courtesy AMLGM
Transportation officials are convinced that the new era of safety devices will be key influencers on reducing the number of fatalities at highway construction sites. The new device, a highway speed bump, has been announced as part of the National Work Zone Awareness Week. The device, a portable rubber rumble strip, has been designed so drivers will get a distinctive rough surface that will eventually get their attention and will became aware of the construction site they are approaching. The rubber strip will be deployed in traffic lanes that are to be gradually closed off at construction sites. The safety device is only about an inch high so they will not create hazards to drivers and smooth enough to be able to switch lanes safely. The rumble strips will be deployed with new barrels topped with flashing, self-synchronizing flashing LED lights. There were 2,749 accidents in construction zones statewide last year, down from the 10-year high of 3,651 in 2011.
The Milton-Madison Bride project is achieving a major milestone today. Walsh Construction Company who is in charge to build the new bridge, has started the process of sliding the bridge into place, the longer bridge ever slide into place in North America. The bridge will be moved 55 feet laterally onto refurbished piers and the new 40-foot-wide bridge includes two 12-foot lanes and 8-foot shoulders -- twice as wide as the original bridge. The slide of the 2,428-foot truss (nearly a half mile) will be historic. The bridge will be moved by hydraulic jacks, each one of them about two feet in diameter. These jacks will be moving the bridge about 20 inches per pull, and the bridge will be moved a total of 55 feet to reach its final destination. Because there will be many stops along the way, the process will take most of the day. Once the slide is complete, it will take up to a week to complete the road connections to the bridge.
Finally the $1 billion California high speed rail will get started. The 29 mile rail project will see its first major sign of construction now that the group who won the bid is starting a 2,000 feet viaduct over highway 145 and Raymond Road. The test piling will start in May and shortly after the contractor will start building the massive structure. The builder will also start a new bridge over the San Joaquin River, elevated tracks at the north and south ends of Fresno; a tunnel under Belmont Avenue and Highway 180, and a dozen street or road over- and underpasses. This portion of the project should be completed by 2017.
However the project has been under fire as legal battles are making this project even more challenging. The project is now on a difficult position that could eventually run out of money if this issues don't get resolved fast.
OSHA has announced that a new regulation is being proposed to amend the existing the current ruling for workers performing electric-power generation, transmission and distribution work. The original standard published in 1972 will be addressing constant and new changes on electric power lines and to create a more consistent version of it. The new version will include changes on how contract employees can share safety-related information with each other and with employees. It will also release updated information on fall protection for employees working from aerial lifts and on overhead line structures, as well as redefine standards on how the approach-distance requirements used to protect workers from energized equipment. The final rule also adds new requirements to protect workers from electric arcs, according to OSHA. 'The new standard for electrical protective equipment applies to all construction work and replaces the existing construction standard, which was based on out-of-date information, with a set of performance-oriented requirements consistent with the latest revisions of the relevant consensus standards,' OSHA said. The new standards address the safe use and care of electrical protective equipment, including new requirements that equipment made of materials other than rubber provide adequate protection from electrical hazards.
One of the most important projects in the eastern coast of the United States is facing a unique problem: they can't find skilled workers. The Tappan Zee Bridge builder is looking to find skilled welders that can be through the testing required to become part of the team. The welders are required to put together steel piles that will support the new crossing. During a one week period as many as 24 welders are rejected because they can pass the required evaluations for welding during X-ray tests. More than 1,000 steel piles will be installed as part of the reconstruction of the new Tappan Zee Bridge, work that will last until 2015. Only 130 steel piles have been installed, each one at least 130 feet ling and 6 feet wide. These piles are driven into the riverbed and then the second portion of the steel pile needs to welded to the previous one as they are filled with steel-reinforced concrete. As of right now, the project seems to be on time and within budget, but there is a concern that the inability to find skilled workers, the project might fall behind schedule. Most of the actual welders have been brought by the Dockbuilders Local 1556,however, the standards that the welders needs to be in compliance with, are higher than expected.
The contractor has been asked to provide a minimum design warranty of at least 100 years. The steel piles will support 42 piers over which the roadway will be built. These piles will support the bridge's eight towers standing 419 feet above the Hudson. Work on the towers and some structural steel work could begin by the end of this year.
The government of Peru has awarded to a sole bidder the construction of what could be the most expensive infrastructure project in the South American Country. The project, a $6 Billion subway system, was awarded to a single bidder shortly after two of the three bidders drop out of the bidding process. European firms, Finmeccanica and ACS, will build and maintain the 21 mile subway system over a 35 year Private Public Partnership. However, professional engineering associations from Peru are asking the government to cancel the awarding process as they are indicating the project cost can be reduced by more than $2 billion if a detailed value engineering analysis is completed prior to contract execution.
The 21 mile subway project, will have 35 new stations, and a tunnel system that will likely be designed as single bores with twin tracks. Excavation is anticipated to be completed in two stages at an average depth of 65 feet. Engineering associations are proposing a combined overhead and tunnel system just below the surface, with deep tunnels limited to the section under the colonial center. That combination is expected to save over $2.3 billion off the project cost.
A 5.3 quake shook California late Friday and a couple of smaller replicas were felt throughout the night. The area has seen increased level of activity during the last weeks but no major damages have occurred. However it is always important to remember some basic tips that you can do in your construction project to secure it against earthquakes. Here are some tips that you can use:
- Nail plywood to the ceiling joists at the basement level to prevent bricks from falling from the chimney
- Hang lights, and other decorative elements in wood beams, do not attached them to the ceiling panels.
- Use L shaped braces screwed unto studs to secure shelves, cabinets and furniture
- Replace rigid piping with flexible pipes that can move if an earthquake is occurring
- Install an automatic shut off valve on the gas line
There are might be other things that you can do but at least these are the most simple ones.
A paper released by the Seattle Times presented evidence that during 1999 the U.S. Army Corps of Engineers, warn of "the potential for a large catastrophic failure." However during the 1950's an initial assessment of the area by a professional firm recommended to build berms and reinforcing the slide area to prevent further damages following some initial slides. In addition to that a geologist also indicated that permanent structures were required to stabilize the area. There is no evidence that these recommendations were established although smaller berms and temporary detention structures were built in the area. The Seattle Times indicated that 'In the summer of 2006, crews went on to install a 1,300-foot "crib wall" of boom logs -- some more than 3 feet in diameter -- anchored with 9,000-pound concrete blocks every 50 feet.'.
Recently several strategies were deployed to protect the area from landslide such as rebuilding the hillside, adding drainage systems to prevent saturation, and building up the toe of the previous slide to curb erosion. Now it is time to rethink and protect other areas from this type of event.
Photo Washington National Guard
Oklahoma has made some changes to their building code that will enter into effect by mid April, requiring new homes built to withstand winds of up to 135 mph. This will make some of these cities, the first ones that promotes such regulations preventing tornado damages. The building standard establishes that homes should be built to withstand winds of up to 90 mph. Building officials have indicated houses still need to provide storm shelters even the ones built under the new regulation. It has been said that the changes will increase the cost of home building by about $1 per square foot. The changes go into effect April 17.