Partially and fully earth-anchored cable-stayed bridges using main-span prestressing unit and method of constructing the same

A method of constructing a fully earth-anchored cable-stayed bridge using a main-span prestressing unit, the method comprising:

• (a) installing first and second main towers a predetermined distance apart from each other in an axial direction of the bridge, a first anchorage on a side of a side span outside the first main tower, and a second anchorage on a side of a side span outside the second main tower;
• (b) connecting tension cables, which extend from the first and second anchorages toward a main span via the first and second main towers, to first and second main-span deck segments, which are continuously installed from the first and second main towers to a middle part of the main span in sequence, such that a tensile stress is applied to each main-span deck segment;
• (c) connecting the first and second main-span deck segments, which are continuously installed from the first and second main towers, to each other at the middle part of the main span, using a prestressing member installed between first and second anchor units installed on the first and second main-span deck segments respectively, the prestressing member being prestressed and anchored between the first and second anchor units;
• and
• (d) installing side-span deck segments from the first and second main towers toward the side spans.

A partially earth-anchored cable-stayed bridge using a main-span prestressing unit comprising:

• first and second main towers spaced a predetermined distance apart from each other in an axial direction of the bridge;
• first and second anchorages on sides of side spans outside the first and second main towers, respectively,
• first side-span and main-span deck segments), which extend from the first and second main towers toward the side spans and a middle part of a main span and are connected to compression cables connected to the first and second main towers such that the first main-span deck segments are separated in the axial direction of the bridge without interconnection at the main span;
• first and second anchor units on the second and third main-span deck segments separated in the axial direction of the bridge;
• and
• a prestressing member including a steel stranded cable, which is mounted between the first and second anchor units and is prestressed and anchored in connection to the first and second main-span deck segments,
• wherein the prestressing member applies a tensile stress to the first and second main-span deck segments.

A fully earth-anchored cable-stayed bridge using a main-span prestressing unit comprising:

• first and second main towers spaced a predetermined distance apart from each other in an axial direction of the bridge;
• first and second anchorages on sides of side spans outside the first and second main towers;
• tension cables, which extend from the first and second anchorages toward a main span via the first and second main towers, and are connected to first and second main-span deck segments, which are continuously installed from the first and second main towers to a middle part of the main span in sequence, such that a tensile stress is applied to each main-span deck segment;
• (c) a prestressing member installed between first and second anchor units installed on the first and second main-span deck segments respectively and prestressed and anchored between the first and second anchor units, the first and second main-span deck segments, which are continuously installed from the first and second main towers, being connected to each other at the middle part of the main span;
• and
• side-span deck segments installed from the first and second main towers toward the side spans.