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Fore River bridge openings
Bridge builders began Fore river bridge construction from lifting the highway span of the bridge in Boston. Everything goes according to Fore River bridge schedule with using Enerpac Jack and Erector Set Bridge.
The Fore River bridge project has started recently. The traffic in the strait has been stopped for three days. An arched span of the Weymouth Fore River Bridge of 227 meters in length and 45 meters in height was delivered to the bridge on the floating systems. Further, with the help of hydraulic and lifting equipment, the arch of the Fore River Bridge Quincy MA would be installed on the 35-meter-high fairway.
The lock crane is used during the process. Most often, it is used for the installation of beams of spans and elements of bridges and overpasses. The locking crane consists of a truss with rear and middle supports mounted on the undercarriages. The A-pillar installed when working on the permanent support of the bridge. On the lower belt of the farm, two cargo trolleys are moved, designed to install the bridge elements.
A bracket is installed at the front end of the truss. A second bracket is attached to the rear end of the truss. The coupler is directly attached to the first bracket, and the power cylinder connected to the other end of the tie is attached to the second bracket.
The footage of the transportation of the road arch of the bridge in Boston appeared in the network. The rise, according to the forecast, would last eight hours. The lifting of the road arch involved 12 jacks with a load capacity of 650 tons each. That is, the total equipment carrying capacity is 7,800 tons. This gives a 30% margin on the lifting capacity of the system in working with the road arch of the bridge.
The road arch is structurally different from the already installed railway, the weight of which is a thousand tons more: the connection of the lower belt with the arch is provided by flexible suspensions – solid steel ropes with a thickness of six centimeters. During transportation and installation, the arch geometry is supported by auxiliary elements – stops. They will be dismantled after the arch takes the designed position on the fairway.
Design features
The history of the construction of bridges names them as one of the oldest engineering inventions of mankind. They are distinguished by design and physical characteristics. The features of the design of metal and reinforced concrete bridges and means of their architectural composition also differ.
The span structures consist of supporting structures: beams, trusses, diaphragms (transverse beams) and the roadway plate itself. The static scheme of span structures can be arched, beam, frame, cable-stayed or combined. It determines the type of bridge by design. Usually, the span structures are straightforward, but if necessary (for example, when building overpasses and road junctions), they are given a complex shape: spiral-shaped, ring-shaped, etc.
Forms of supports can be very diverse. Intermediate supports are called bulls, coastal – abutments. Abutments are used to connect the bridge with suitable embankments.
Materials for bridges are metal (steel and aluminum alloys), reinforced concrete, concrete, natural stone, wood, cables. Only professionals in their field worked on the construction of the bridge in Boston, so there is no doubt in the reliability of its design.