Supporting Documentation · Oct 12, 2022
PB 22 10 Altera 769 LLC Filed Application with Exhibits Final Site Plan Phase 2
df1f56d8dfa009ca73b3855c637d68cc5e7491530b6196991d8f0dc5018cdfe1Indexed text · page 131
Show all pagesDate: 6/8/2022 Project: Altera Project No: 2530-99-006 245 Main Street, Suite 110, Chester, NJ 07930 Calculated By: SDP (908) 879-9229 Checked By: RJC Conduit Outlet Protection Calculations Rip Rap Pad # A Design Parameters: Design Storm Flow for 25 Year, Q . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.90 cfs Vertical Dimension of Outlet Pipe, D o . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 in Horizontal Dimension of Outlet Pipe, W o . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 in Tailwater Depth, TW 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.15 ft Apron Dimension Calculations: Unit Dicharge, q = Q/D o = 3.27 cfs per foot • Case I: TW < 1/2 D o 1.8q Apron Length, L a = + 7D o = 15.3 ft or La = 16 ft D o 1/2 Width, W 1 = 3W o = 4.5 ft or W1 = 5 ft Width, W 2 = 3W o + L a = 19.8 ft or W2 = 20 ft • Case
5 ft Width, W 2 = 3W o + L a = 19.8 ft or W2 = 20 ft • Case II: TW ≥ 1/2 D o 3q Apron Length, L a = = La = D o 1/2 Width, W 1 = 3W o = W1 = Width, W 2 = 3W o + 0.4L a = W2 = Rip Rap Stone Size Calculations: 1.33 Median Stone, d 50 = 0.02q = 7.72 in d 50 = 8 in TW Notes: 1. Where there is a well-defined channel downstream of the apron, the bottom width of the apron shall be at least equal to the bottom width of the channel and the structural lining shall extend at least one foot above the tailwater elevation, but no lower than two-thirds of the vertical conduit dimension above the conduit invert. 2. The side slopes shall be 2:1 or flatter. 3. The bottom grade shall be 0.0% (level). 4. There shall be no overfall at the end of the apron or at the end of the culvert. 5. Fifty (50) percent by weight of the rip-rap mixture shall be smaller than the median size stone designated as d50. The largest stone size in the mixture shall be 1.5 times the d50 size. The rip-rap shall be reasonably well graded. 6. The thickness of the rip-rap apron may be two (2) times the median stone diameter provided that the apron is constructed on a bedding of four (4) inches of 3/4 inch clean stone on approved filter fabric material. 7. Rip-rap and filter fabric shall meet the standards of the governing Soil Conservation District as well as the requirements of the local municipality.
rial. 7. Rip-rap and filter fabric shall meet the standards of the governing Soil Conservation District as well as the requirements of the local municipality. 8. No bends or curves at the intersection of the conduit and apron will be permitted. Footnote: 1. Tailwater depth shall be the 2-year storm if discharging into a detention basin. For areas where tailwater cannot be computed, use TW = 0.2D o . 2. For multiple pipes, increase rip-rap sizes by 25% when pipe spacing is greater than or equal to 1/4W o .
File revisions (1)
- Sep 29, 2026
df1f56d8dfa054,605,034 bytes