About the Gravity Network Analysis Results Report

From the Results page of the Analyze Gravity Network dialog box, you can output a .csv file which contains the results of the gravity network analysis.

The report is output in a format that is generally similar to computation sheets in the Urban Drainage Design Manual Third Edition, Hydraulic Engineering Circular No. 22 (HEC-22), published by the U.S. Department of Transportation Federal Highway Administration.

Storm drain data

The first set of rows in the table generally follows the data format of HEC-22 Figure 7-8, the storm drain computation sheet. This section is included in the report if you selected Compute Energy and Hydraulic Grade Lines or Resize Pipes and Reset Inverts on the General page of the Analyze Gravity Network dialog box.

The following data is included in this section of the report:

#Line Pipe From To Length Drainage Area Inc Drainage Area Total Runoff Coeff "C" "Area" X "C" Inc "Area" X "C" Total Time of Concentration Inlet Time of Concentration System Rain "I" Runoff "Q" Known Q Total Q Pipe Dia. Full Q Velocity Full Velocity Design Sec Time Invert Elevation U/S Invert Elevation D/S Crown Drop Slope

Energy and hydraulic grade line data

The second set of rows in the table generally follows the data format of HEC-22 Figure 7-10, the energy grade line computation sheet - Table A. This section is included in the report if you selected Compute Energy and Hydraulic Grade Lines on the General page of the Analyze Gravity Network dialog box.

The following data is included in this section of the report:

#Line Struct. ID D Q L V d

dc

v2/2g

EGLo

HGLo

Sf

Total Pipe Loss

EGLi

HGLi

Ea

EGLa

U/S TOC Surface Elev.

The third set of rows in the table generally follows the data format of HEC-22 Figure 7-11, the energy grade line computation sheet - Table B. This section is included in the report if you selected Compute Energy and Hydraulic Grade Lines on the General page of the Analyze Gravity Network dialog box.

The following data is included in this section of the report:

#Line Struct. ID

Exit Ho

Hf

Hb

Hc

He

Hj

Total

Ei

y+(P/γ)

DI

Eai

CB

Cθ

Cp

Ha

Ea

Inlet analysis data

The fourth set of rows in the table generally follows the data format of HEC-22 Figure 4-19, the inlet spacing computation sheet. This section is included in the report if you selected Inlet Analysis on the General page of the Analyze Gravity Network dialog box.

The following data is included in this section of the report:

No. Name Stat. Drain. Area A Runoff Coeff. C Time of Conc. Rainfall Intens.

Q=CIA/Kc

Known Q

Long Slope SL

Cross Slope Sx

Cross Slope Sw

Prev. Bypass Flow Total Gutter Flow Depth d Gutter Width Spread T W/T Inlet Type Grate Length Grate Width Curb Opening Length Curb Opening Height

Intercept Flow Qi

Bypass Flow Qb

Bypass Structure Remark