Composite overfilled arch system
View Patent ↗An overfilled arch bridge system includes a composite arch which has a precast layer and a cast-in-place layer. The system further includes means for reducing bending moments within the overfilled arch. The means include customizing the arch end geometry and prestressing the arch prior to or during loading. The system can be used in connection with the overfilled arch system disclosed in co-pending patent application titled “Top Arch Overfilled System” filed by the same inventor on Mar. 22, 2002.
1. An overfilled arch structure comprising:
overfill material;
a void area formed in the overfill material, the void area having a lower pathway surface, first and second generally vertical sidewalls extending upward from the lower pathway surface, the first and second sidewalls spaced apart by the lower pathway surface; and
an arch spanning the void area, a first end of the arch extending over, and outward beyond the first sidewall and positioned in a non-contacting relationship relative to the first sidewall, the second end of the arch extending over, and outward beyond the second sidewall and positioned in a non-contacting relationship relative to the second sidewall, the arch includes a first arch-shaped layer of precast concrete having a lower surface exposed to the lower pathway surface and a second arch-shaped layer of cast-in-place concrete contiguous with upper surface of the first layer across substantially an entirety of a span of the arch.
2. The overfilled arch structure defined in claim 1 further including reinforcing elements in said first layer and in said second layer.
3. The overfilled arch structure defined in claim 1 further including joints in said first layer, where the second layer is continuous over said joints.
4. The overfilled arch structure defined in claim 1
wherein the first end of the arch is supported by a first concrete footer located near the top of the first sidewall, and the second end of the arch rests on a second concrete footer located near the top of the second sidewall.
5. The overfilled arch structure of claim 4
wherein a lower edge of the first arch footing is spaced higher than the lower pathway surface and a lower edge of the second arch footing is spaced higher than the lower pathway surface.
6. The overfilled arch structure defined in claim 1 further including waterproofing.
7. An overfilled arch structure comprising:
overfill material;
a void area formed in the overfill material, the void area having a lower pathway surface, first and second sidewalls extending upward from the lower pathway surface, the first and second sidewalls spaced apart by the lower pathway surface;
an arch spanning the void area, a first end of the arch extending over, and outward beyond the first sidewall and positioned in a non-contacting relationship relative to the first sidewall, the second end of the arch extending over, and outward beyond the second sidewall and positioned in a non-contacting relationship relative to the second sidewall, the arch includes a first arch-shaped layer of precast concrete having a lower surface exposed to the lower pathway surface and a second arch-shaped layer of cast-in-place concrete contiguous with an upper surface of the first layer across substantially an entirety of a span of the arch;
wherein the first end of the arch is supported by a first concrete footer located near the top of the first sidewall, and the second end of the arch rests on a second concrete footer located near the top of the second sidewall;
wherein a lower edge of the first arch footing is spaced higher than the lower pathway surface and a lower edge of the second arch footing is spaced higher than the lower pathway surface; and
wherein at least one prestressing element is positioned between the first end of the arch and the first concrete footer and at least one other prestressing element is located between the second end of the arch and the second concrete footer.