Compute Depth of LL Surcharge
For the LRFD specification, the user can select this option to let the program calculate the height of the live load surcharge depending on the fill depth and the height of the culvert. Where the user has selected to analyze a range of fill depths, the value of the live load surcharge will also change.
Depth of LL Surcharge
Input the value for the depth of the live load surcharge. This value will be used for all fill depths.
Track Width
For AREMA, the track width can be input here. Note that under AREMA the truck gage width will not be used.
Apply LL Surcharge At Fill Depths Greater Than 2 Feet
Normally the program only applies a live load surcharge when the fill depth is less than 2 feet. By selecting this option you can force the program to apply live load surcharge at all fill depths. If you want to force the program not to apply any live load surcharge for fills less than 2 feet, then set the depth of the live load surcharge equal to zero.
Neglect LL for fill depths greater than 8 feet and greater than span length
Check to have analysis neglect live load for fill height greater than 8 feet and the clear span.
Apply LL Surcharge when LL is neglected
Check to have analysis apply loading due to live load surcharge even when live load is neglected due to fill depth.
Additional Uniform Dead Load
Input an additional uniform dead load. This load is applied to the one foot wide culvert structural model. In other words, to convert an area load to the proper distributed load, simply multiply by 1 foot.
Future Wearing Surface
Input the weight of a future wearing surface (if any), which is also applied to the one foot wide culvert structural model.
Concentrated Dead Loads
Input up to three additional concentrated line loads. For each load, input the magnitude of the load and the location from the centerline of the left most wall.
Equivalent Fluid Pressures
For LRFD, STND and CHBDC, input the maximum and minimum equivalent fluid pressures for lateral earth loads. The default for the maximum is 60 psf, and the default for minimum is 30 psf. The maximum value will be used in those load combinations where the program is calculating the maximum inward pressure on the walls, and the minimum is used where the program is calculating the minimum inward pressure (or maximum outward pressure). The exceptions are LRFD 5th Edition, where the program matches the perceived intent of the 1st Edition of the MBE, and uses the minimum load factor, EHmin, to calculate the minimum inward pressure, and CHBDC, which uses EHmin as well.
Lateral Pressure Coefficients
For AREMA, assign the maximum and minimum lateral pressure coefficients.
Consider Internal Water Pressure
Check to have analysis consider internal water pressure. The program will use either the full height of internal water pressure or no water pressure. Internal water is assumed to have a unit weight of 62.4 pcf.
Internal Pressure Head
Input the pressure head you would like applied to the interior of the culvert. Note that this option is only enabled if “consider internal water pressure is selected”.
Check Buoyancy
If this option is selected, Eriksson Culvert will perform a buoyancy check.
Include Seismic Loads
Select this option if you would like Eriksson Culvert to perform a seismic analysis.
Peak Ground Acceleration (PGA)
Enter the peak ground acceleration in the horizontal direction.
Ground Shear Modulus
Enter the ground shear modulus.
Slip Interface
Select the slip interface, the options are “no slip” and “full slip”.
Additional Uniform Loads
Users have to option of including additional vertical and horizontal uniform loads to the culvert analysis. The uniform vertical load will be applied to the culvert’s top slabs, and the uniform horizontal load will be applied to the culvert’s exterior walls. To enable these options, use the check boxes ‘Include additional horizontal load’ and ‘Include additional vertical load’.
For each of these loads, you will be required to input a magnitude and load type (dead, live, or earth). The load type determines with load factor will be applied.
Wall Loads
For inverted three-sided culverts, the ability to add wall loads will be enabled. This allows users the option to add vertical point loads (with or without eccentricities) to the top of the culvert walls.