Effects of Inlet Geometry on Hydraulic Performance of Box Culverts

APPENDIX A. EXPANDED TEST MATRIX

This appendix is an expanded description of the test matrix. The expanded matrix includes sketches, more detailed information about test conditions, and extra tests that were conducted in response to questions posed during the study. The matrix was posted in the lab and used as a checklist during the experimental phase.

Figure 30 in chapter 5 contains the seven different bevel edge configurations that were tested in the miniflume to determine the best edge configuration. The criterion to determine the best edge configuration was the contracted distance outside the viscous boundary layer (effective flow depth at the vena contracta, also illustrated in figure 30). PIV data were used to analyze the flow at the culvert entrance and to quantify the effective flow depth.

Tables 13 through 16 summarize tests performed in the culvert test facility to analyze the effects of bevels, multiple barrels, span–to–rise ratios, and skewed headwalls. Two extra inlet geometries—an FC–S–0 hybrid and a PC–A hybrid—were tested in response to questions on the draft final report regarding the wingwall bevels and are included in table 16. The FC–S–0 hybrid was a combination of the field cast top bevel with the precast wingwall bevels, and the PC–A hybrid was a combination of the precast top bevel with the field cast square edge wingwalls.

Table 13. Tests to analyze the effects of bevels for wingwalls and top edges.

Inlet	Model ID	Sketch	Wingwall flare angle	Bevels	Corner fillets (inches)	Barrel size (feet)	Culvert slopes	Tailwater
1.1	FC–S–0		0°	4–inch–straight top bevel, no WW bevel	0	6 × 6	0.03, 0.007	High,Low
1.2	FC–S–0		0°	4–inch–straight top bevel, no WW bevel	6	6 × 6	0.03, 0.007	High,Low
1.3	FC–S–0		0°	4–inch–straight top bevel, no WW bevel	12	6 × 6	0.03, 0.007	High,Low
1.4	PC–A		0°	8–inch–radius top bevel, 4–inch–radius WW bevels	0	6 × 6	0.03, 0.007	High,Low
1.5	PC–A		0°	8–inch–radius top bevel, 4–inch–radius WW bevels	6	6 × 6	0.03, 0.007	High,Low
1.6	PC–A		0°	8–inch–radius top bevel, 4–inch–radius WW bevels	12	6 × 6	0.03, 0.007	High,Low
1.7	PC–A		0°	8–inch–radius top bevel, 4–inch–radius WW bevels	6	6 × 12	0.03	High,Low
1.8	PC–A		0°	8–inch–radius top bevel, 4–inch–radius WW bevels	12	6 × 12	0.03	High,Low
1.9	FC–S–0 Hybrid		0°	4–inch–straight top bevel, 4–inch–radius WW bevels	0	6 × 6	0.03	High,Low
1.10	PC–A Hybrid		0°	8–inch–radius top bevel, no WW bevels	0	6 × 6	0.03	High,Low

1 inch = 2.54 cm; 1 ft = 0.305 m

Notes: Target discharge intensities for unsubmerged flow, Q⁄AD0.5 = 0.5, 1.0, 2.0, 3.5, and 4.0 (ft0.5⁄s). Target discharge intensities for submerged flow, Q⁄AD0.5 = 4.5, 5.0, 5.5, and 6.0 (ft0.5⁄s). One ft0.5⁄s equals 0.552 m0.5⁄s. Contraction ratio of headbox width to total span of culvert model was held constant at 2.67. WW is wingwalls.

Table 14. Tests to analyze the effects of multiple barrels.

Inlet	Model ID	Sketch	WW flare angle	Bevels	Barrel size (feet)	Culvert slopes	Corner fillets (inches)	Barrels	Inner Wall
2.1	FC–S–0		0°	4–inch–straight top bevel, no WW bevel	6 × 6	0.03, 0.007	6	1	None
2.2	FC–S–30		30°	4–inch–straight top bevel, no WW bevel	6 × 6	0.03, 0.007	6	1	None
2.3	FC–D–0		0°	4–inch–straight top bevel, no WW bevel	6 × 6	0.03, 0.007	6	2	Not extended
2.4	FC–D–0–E		0°	4–inch–straight top bevel, no WW bevel	6 × 6	0.03, 0.007	6	2	Extended
2.5	FC–D–30		30°	4–inch–straight top bevel, no WW bevel	6 × 6	0.03, 0.007	6	2	Not extended
2.6	FC–D–30–E		30°	4–inch–straight top bevel, no WW bevel	6 × 6	0.03, 0.007	6	2	Extended
2.7	FC–T–0		0°	4–inch–straight top bevel, no WW bevel	6 × 6	0.03, 0.007	6	3	Not extended
2.8	FC–T–0–E		0°	4–inch–straight top bevel, no WW bevel	6 × 6	0.03, 0.007	6	3	Extended
2.9	FC–T–30		30°	4–inch–straight top bevel, no WW bevel	6 × 6	0.03, 0.007	6	3	Not Extended
2.10	FC–T–30–E		30°	4–inch–straight top bevel, no WW bevel	6 × 6	0.03, 0.007	6	3	Extended
2.11	FC–Q–0		0°	4–inch–straight top bevel, no WW bevel	6 × 6	0.03, 0.007	6	4	Not extended
2.12	FC–Q–0–E		0°	4–inch–straight top bevel, no WW bevel	6 × 6	0.03, 0.007	6	4	Extended
2.13	FC–Q–30		30°	4–inch–straight top bevel, no WW bevel	6 × 6	0.03, 0.007	6	4	Not extended
2.14	FC–Q–30–E		30°	4–inch–straight top bevel, no WW bevel	6 × 6	0.03, 0.007	6	4	Extended
2.15	PC–A		0°	8–inch–radius top bevel, 4–inch–radius WW bevels	6 × 6	0.03, 0.007	12	1	None
2.16	PC–B		0°	8–inch–radius top bevel, 4–inch–radius WW bevels	6 × 6	0.03, 0.007	12	2	Not extended
2.17	PC–B–E		0°	8–inch–radius top bevel, 4–inch–radius WW bevels	6 × 6	0.03, 0.007	12	2	Extended
2.18	PC–C		0°	8–inch–radius top bevel, 4–inch–radius WW bevels	6 × 6	0.03, 0.007	12	3	Not extended
2.19	PC–C–E		0°	8–inch–radius top bevel, 4–inch–radius WW bevels	6 × 6	0.03, 0.007	12	3	Extended
2.20	PC–D		0°	8–inch–radius top bevel, 4–inch–radius WW bevels	6 × 6	0.03, 0.007	12	4	Not extended
2.21	PC–D–E		0°	8–inch–radius top bevel, 4–inch–radius WW bevels	6 × 6	0.03, 0.007	12	4	Extended

1 inch = 2.54 cm; 1 ft = 0.305 m

Notes: Target discharge intensities for unsubmerged flow, Q⁄AD0.5 = 0.5, 1.0, 2.0, 3.5, and 4.0 (ft0.5⁄s). Target discharge intensities for submerged flow, Q⁄AD0.5 = 4.5, 5.0, 5.5, and 6.0 (ft0.5⁄s). One ft0.5⁄s equals 0.552 m0.5⁄s. Contraction ratio of headbox width to total span of culvert model was held constant at 2.67. WW is wingwalls.

Table 15. Tests to analyze the effects of the span–to–rise ratio.

Inlet	Model ID	Sketch	WW flare angle	Bevels	Barrel size (feet)	Culvert Slopes	Corner fillets (inches)	Span–to–rise
3.1	FC–S–0		0°	4–inch–straight top bevel, no WW bevel	6 × 6	0.03, 0.007	0	1:1
3.2	FC–S–30		30°	4–inch–straight top bevel, no WW bevel	6 × 6	0.03, 0.007	0	1:1
3.3	PC–A		0°	8–inch–radius top bevel, 4–inch–radius WW bevels	6 × 6	0.03, 0.007	0	1:1
3.4	FC–S–0		0°	4–inch–straight top bevel, no WW bevel	6 × 12	0.03, 0.007	0	2:1
3.5	FC–S–30		30°	4–inch–straight top bevel, no WW bevel	6 × 12	0.03, 0.007	0	2:1
3.6	PC–A		0°	8–inch–radius top bevel, 4–inch–radius WW bevels	6 × 12	0.03, 0.007	0	2:1
3.7	FC–S–0		0°	4–inch–straight top bevel, no WW bevel	6 × 18	0.03, 0.007	0	3:1
3.8	FC–S–30		30°	4–inch–straight top bevel, no WW bevel	6 × 18	0.03, 0.007	0	3:1
3.9	PC–A		0°	8–inch–radius top bevel, 4–inch–radius WW bevels	6 × 18	0.03, 0.007	0	3:1
3.10	FC–S–0		0°	4–inch–straight top bevel, no WW bevel	6 × 24	0.03, 0.007	0	4:1
3.11	FC–S–30		30°	4–inch–straight top bevel, no WW bevel	6 × 24	0.03, 0.007	0	4:1
3.12	PC–A		0°	8–inch–radius top bevel, 4–inch–radius WW bevels	6 × 24	0.03, 0.007	0	4:1

1 inch = 2.54 cm; 1 ft = 0.305 m

Notes: Target discharge intensities for unsubmerged flow, Q⁄AD0.5 = 0.5, 1.0, 2.0, 3.5, and 4.0 (ft0.5⁄s). Target discharge intensities for submerged flow, Q⁄AD0.5 = 4.5, 5.0, 5.5, and 6.0 (ft0.5⁄s). One ft0.5⁄s equals 0.552 m0.5⁄s. Contraction ratio of headbox width to total span of culvert model was held constant at 2.67. WW is wingwalls.

Table 16. Tests to analyze the effects of skew.

Inlet	Model ID	Sketch	WW flare angle	Bevels	Barrel size (feet)	Culvert slopes	Corner fillets (inches)	Barrels	Span–to–rise	Skew
4.1	FC–T–0		0°	4–inch–straight top bevel, no WW bevel	6 × 6	0.03,0.007	0	3	–	0°
4.2	FC–T–30		30°	4–inch–straight top bevel, no WW bevel	6 × 6	0.03,0.007	0	3	–	0°
4.3	FC–T–30		30°	4–inch–straight top bevel, no WW bevel	6 × 6	0.03,0.007	0	3	–	15°
4.4	FC–T–30		30°	4–inch–straight top bevel, no WW bevel	6 × 6	0.03,0.007	0	3	–	30°
4.5	FC–T–30		30°	4–inch–straight top bevel, no WW bevel	6 × 6	0.03,0.007	0	3	–	45°
4.6	FC–S–30		30°	4–inch–straight top bevel, no WW bevel	6 × 18	0.03,0.007	0	–	3:1	30°

1 inch = 2.54 cm; 1 ft = 0.305 m

Notes: Target discharge intensities for unsubmerged flow, Q⁄AD0.5 = 0.5, 1.0, 2.0, 3.5, and 4.0 (ft0.5⁄s). Target discharge intensities for submerged flow, Q⁄AD0.5 = 4.5, 5.0, 5.5, and 6.0 (ft0.5⁄s). One ft0.5⁄s equals 0.552 m0.5⁄s. Contraction ratio of headbox width to total span of culvert model was held constant at 2.67. WW is wingwalls.

Previous | Contents | Next

Page Owner: Office of Research, Development, and Technology, Office of Infrastructure, RDT Scheduled Update: Archive - No Update Technical Issues: TFHRC.WebMaster@dot.gov Topics: research, infrastructure, hydraulics Keywords: research, infrastructure, hydraulics, Culvert, inlet, headwall, wingwall TRT Terms: research, hydraulics, hydrology, fluid mechanics, earth sciences, geophysics Updated: 04/23/2012