Structural Model
In-Place Condition
Bearing
The bearing section contains all the inputs required for the plain and reinforced bearing capacity analysis. For more information on these inputs and the analysis see Bearing Capacity.
Dapped Ends
Information about dapped ends are input in this section, for more information on the analysis and assumptions made see Dap Design.
Input | Description |
|---|---|
Length | The length of the dap down the length of the member. |
Height | The height of the dap through the member thickness. |
Deck Heldback | If checked, will remove the deck above the dap. |
Nu / Vu | Ratio of axial load to shear load to be used in the analysis. |
Assumed Bar Diameter | Assumed bar diameter used tto calculate reinforcement depths. |
Modify Concrete Extents | If checked, the dap will be removed from the concrete cutting all reinforcement in it’s location. |
Thin webbed member | if checked, the dap analysis will use the thin webbed member provisions. |
Ledge
Information about the ledges are input in this section, for more information on the analysis and assumptions made see Ledge Design.
Input | Description |
|---|---|
End / Middle Distribution Width | The analysis computes the total quantity of steel required at a given location in terms of an area. That area is divided by the user defined distribution width to convert it into a steel areas required per square foot. If total area of steel required is desired, input 1 foot. |
Load Bearing Width | The bearing width of the load on the ledge. |
Closed ties used for ledge reinforcement | If checked the analysis will assume closed ties. |
Steel cover + radius | The total cover plus bar radius used to compute the reinforcement depth. |
Vu | The applied shear load on a given ledge. |
Eccentricity | The distance from the face of the stem to the load location. |
Load Spacing | The spacing of the load defined above. |
Nu / Vu | The ratio of axial load to shear force being transferred to the ledge. |
Vibration Analysis
Information about the vibration analysis are input in this section, for more information on the analysis and assumptions made see Vibration Analysis.
Input | Description |
|---|---|
Acceleration Limit | The limit the engineer puts on the acceleration. These typically come from the PCI Design Handbook 8th Edition Table 12.7.1 Recommended acceleration limits. |
Acceleration Coefficient | The acceleration coefficient, kr, typically comes from the PCI Design Handbook 8th Edition Table 12.7.2. |
Additional Expected Load | The additional expected sustained load to be included in the total weight of the member. Note that this is not the superimposed loading but the true expected loads that will be present at the time of vibration. |
Weight of Participants | The weight of partitcipants, wp, typically comes from the PCI Design Handbook 8th Edition Table 12.7.2. |
Dynamic Coefficient | The dynamic coefficient, αi, typically comes from the PCI Design Handbook 8th Edition Table 12.7.2. |
Loading Width | The tributary width of the member to be loaded. |
Non uniform bay widths and in plan angle > 5 degrees | If checked the minimum frequency requirement will be reduced by 25% per section 12.7.2 of the PCI Design Handbook 8th Edition. |
Forcing frequency | The forcing frequency, fr, typically comes from the PCI Design Handbook 8th Edition Table 12.7.2. |
Loading
Loads can be entered as vertical concentrated loads, vertical line loads, vertical area loads, point moments, lateral concentrated loads, lateral line loads, and lateral area loads. Because of this it is possible to perform a biaxial analysis within Eriksson Beam.
At a given loading location, the user can defined the non composite dead load, topping load, composite dead load, live load, roof load (snow / rain), wind pressure, wind section, and seismic. All loads types assume a positive load is pointing downwards. For suction loading the engineer must indicate magnitude themself.
When performing the analysis only pressure or suction will be present at a time on the member. It is also assumed the sign of seismic loads can change and thus it will also reverse the sign of seismic loading and check that case as well.
Loading Options
Options | Description |
|---|---|
Live load(s) applied as roof loads | Live loads input will be input as Lr and use the Roof load factors |
Automatically add topping weight | Automatically computes topping weight based on geometry input on concrete extents tab and applied it to the member |
Ignore left cantilever loading | Ignores all loading before the first bearing point. This option can be used to prevent negative moments prior to the start bearing point. |
Ignore right cantilever loading | Ignores all loading after the end bearing point. This option can be used to prevent negative moments after the final bearing point. |
Self weight multiplier | Allows the user to modify the self weight. |
Self weight eccentricity | Allows the self weight to apply a distributed torsion load on the member. |
Roof loads applied as… | Live Load: Will be considered for live load regain for losses and not use any deflection multipliers. Composite Dead Load: Will be treated as a sustained load for losses and use the composite dead load deflection multiplier |
Stripping and Handling
Stripping and handling contains three optional stages for stripping, handling, and erection. More details about what these stages contains can be found on our analysis stages page here: Analysis Stages. Each of these stages contain the following input:
Input | Description |
Load Multiplier | A load factor used on all self-weight loading for the given analysis stage. |
Downward Face | Specifies which face of the member, as shown on the concrete extents tab, is downward facing. This option can be used for members such as spandrels which are often cast on their side. |
Concrete Strength | Specifies if the analysis should use the initial concrete properties (fci and Eci) or the final concrete properties (fc and Ec). |
Stress Limits | Sets the stress limits to be either the transfer stress limits or to use the in-place serviceability checks. |
Pick Points | Sets the analysis to use a 2-point or a 4-point pick. The 4-point pick analysis uses a rolling block analysis to couple the first two reactions together and the last two reactions together. |
Lift Locations | Defines the lifting locations as measured from the specified end of the member. Lateral locations of the lifters are ignored. |