About the Gravity Network Analysis Results Report

From the Results page of the Analyse 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 US 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 Gradient Lines or Resize Pipes and Reset Inverts on the General page of the Analyse 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 Level U/S Invert Level D/S Soffit Drop Slope

Energy and hydraulic gradient line data

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

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

Crossfall Sx

Crossfall Sw

Prev. Bypass Flow Total Channel Flow Depth d Channel Width Spread T W/T Inlet Type Gully Length Gully Width Kerb Opening Length Kerb Opening Height

Intercept Flow Qi

Bypass Flow Qb

Bypass Structure Remark