Cables and Arches - Examples & Applications
Mathematical Theory Examples
Example 1: Cable Subjected to Concentrated Loads
A flexible cable is anchored at two supports A and B, which are at the same elevation and apart. A single concentrated load of is hung exactly in the middle of the span (). The sag at the center is measured to be . Determine the maximum tension in the cable. Neglect the weight of the cable.
Step-by-Step Solution
0 of 3 Steps CompletedExample 2: Parabolic Cable (Uniformly Distributed Horizontal Load)
A suspension bridge cable has a span of and a maximum sag of . It supports a uniformly distributed deck load of (measured horizontally). Determine the equation of the cable shape and the maximum tension.
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0 of 3 Steps CompletedExample 3: Catenary Cable (Uniformly Distributed Load Along Cable)
A high-voltage transmission line is strung between two towers apart. The cable itself weighs along its own length. If the minimum tension in the cable (at the lowest point) is , find the maximum sag.
Step-by-Step Solution
0 of 2 Steps CompletedExample 4: Cable with Two Concentrated Loads
A flexible cable is supported at and , which are at the same elevation and apart. The cable is subjected to two concentrated loads: at from , and at from . If the sag at the first load is , determine the sag at the second load and the maximum tension in the cable.
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0 of 4 Steps CompletedExample 5: Three-Hinged Arch with Concentrated Load
A three-hinged semicircular arch has a radius of and is supported by pin connections at and , which are at the same elevation. A hinge is located at the crown . A concentrated load of is applied vertically at a point , which is located on the arch at a horizontal distance of from the left support . Determine the horizontal thrust at the supports and the vertical reactions.
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0 of 3 Steps CompletedExample 6: Three-Hinged Parabolic Arch with Uniform Load
A three-hinged parabolic arch has a span of and a rise (height at the crown) of . The hinges are located at the two supports, and , which are at the same elevation, and at the crown . The arch carries a uniformly distributed load of over its entire horizontal span. Determine the horizontal thrust and the maximum bending moment in the arch.
Step-by-Step Solution
0 of 3 Steps CompletedExample 7: Cable with Unequal Support Elevations
A cable is attached to two supports and . Support is higher than support . The horizontal distance between the supports is . The cable carries a uniform load of along the horizontal span. The lowest point of the cable is below support . Determine the horizontal tension in the cable and the distance from support to the lowest point.
Step-by-Step Solution
0 of 3 Steps CompletedExample 8: Catenary Cable Length Calculation
A uniform cable weighing is suspended between two points and , which are on the same horizontal line and apart. The horizontal tension in the cable is known to be . Determine the maximum sag and the total length of the cable.
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0 of 3 Steps CompletedCase Studies: Conceptual Theory
Case Study 1: Parabola vs. Catenary in Bridge Engineering
The main cables of the Golden Gate Bridge are often assumed to be parabolas, while the cables of high-voltage transmission lines are modeled as catenaries. What is the fundamental physical difference in the loading that causes these two distinct mathematical shapes?
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0 of 1 Steps CompletedCase Study 2: The Funicular Shape of Arches
The Gateway Arch in St. Louis is designed in the shape of an inverted weighted catenary. How does the concept of a "funicular shape" relate arches to hanging cables, and why is this shape structurally ideal?
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0 of 1 Steps CompletedCase Study 3: Three-Hinged vs. Two-Hinged Arches (Determinacy and Temperature)
When designing a large span arch bridge, an engineer must choose between a three-hinged arch and a two-hinged arch. What is the fundamental difference in their static determinacy, and how does this affect their response to temperature changes and foundation settlement?
Step-by-Step Solution
0 of 2 Steps CompletedCase Study 4: Tied Arches (Bowstring Arches) and Horizontal Thrust Resolution
Many modern arch bridges, such as the Sydney Harbour Bridge or various river crossings, use a "tied-arch" or "bowstring arch" design. In classic arches, the horizontal thrust must be resisted by massive abutments built into the earth. How does a tied-arch bridge resolve this issue, and what structural member acts analogously to the tension cable in a suspension bridge?