Critical Section Tables

Critical section tables are shown in multiple places throughout the Eriksson Culvert text report:

  1. The “Critical Section Summary” is near the top of the report and shows the controlling critical section for each location.

  2. The “Strength Limit State at Critical Sections” tables are displayed for each truck/fill depth combination in the analysis. These tables provide design information at each critical section for the particular truck/fill depth analysis.

 

Now we will discuss each column in the flexural critical section tables:

Table Column

Description

Table Column

Description

Loc

A description of the location of the critical section. For box culverts, the following critical sections are analyzed:

  • For walls: Bottom, Middle+ (positive moment), Middle- (negative moment), and Top

  • For slabs: Left, Middle, and Right

Dist.

The distance column displays the location of the critical section, measured in inches, from the centerline of the intersecting member (or from the corresponding node in the FEM analysis). For instance, in the above screenshot, the exterior wall bottom critical section is located at 8.5”. This means it is 8.5” up from the centerline of the bottom slab. Additionally, the exterior wall top critical section is located at 9.0”, which is 9.0” down from the centerline of the top slab.

Design Moment

The maximum factored moment being applied at the critical section location.

Corr. A.F.

The corresponding axial force given by the same load combination that produced the design moment.

Mu

The capacity of the section, not taking axial force into account.

ds

Depth to the flexural steel.

Ma

The capacity of the section, considering axial forces.

As

Area of flexural steel.

Mcr

The cracking moment.

IR

Inventory load rating.

OR

Operating load rating.

Truck

The truck from the corresponding truck/fill depth combination that produced this load case. (Only shown in the Critical Section Summary)

Fill Depth

The fill depth from the corresponding truck/fill depth combination that produced this load case. (Only shown in the Critical Section Summary)

 

Now we will discuss each column in the shear critical section tables:

Table Column

Description

Table Column

Description

Loc

A description of the location of the critical section. For box culverts, the following critical sections are analyzed:

  • For walls: Bottom, Middle+ (positive moment), Middle- (negative moment), and Top

  • For slabs: Left, Middle, and Right

Dist.

The distance column displays the location of the critical section, measured in inches, from the centerline of the intersecting member (or from the corresponding node in the FEM analysis). For instance, in the above screenshot, the exterior wall bottom critical section is located at 13.15”. This means it is 13.15” up from the centerline of the bottom slab. Additionally, the exterior wall top critical section is located at 13.65”, which is 13.65” down from the centerline of the top slab.

Design Shear

The maximum factored shear being applied at the critical section location.

Corr. Moment

The corresponding moment given by the same load combination that produced the design shear.

Corr. A.F.

The corresponding axial force given by the same load combination that produced the design moment.

Dv

Depth to the flexural steel.

Vc

Shear capacity of the concrete section.

Vs

Shear capacity of the added shear steel.

Av

Area of provided shear steel.

Max Spacing

Maximum spacing of the shear reinforcement.

IR

Inventory load rating.

OR

Operating load rating.

Truck

The truck from the corresponding truck/fill depth combination that produced this load case. (Only shown in the Critical Section Summary)

Fill Depth

The fill depth from the corresponding truck/fill depth combination that produced this load case. (Only shown in the Critical Section Summary)