Detailed punching shear check
Function Punching > Punching check in service Concrete Advanced offers the action button named [Single check]. This button opens a dialogue for detailed punching shear check.
The dialogue is divided into several tabs:
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Geometry of punching
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Loads
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Main reinforcement (not for CSN/STN)
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Design of reinforcement
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Reinforcement for punching (only CSN/STN)
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Check (only CSN/STN)
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Document setup
In addition, the results can be previewed in the Preview window or exported to the Document.
Geometry of punching
The data on this tab are mainly used to determine the critical perimeter.
Column type group
Column position group
The following column positions are available:
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parallel to the x-side,
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parallel to the y-side,
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corner column,
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internal column.
The axes in the picture are the axes of the plate
Parallel to the x-side
Column distance y |
Distance in the y-direction between the edge of the slab and the nearest face of the column. |
Parallel to the y-side
Analogous to parallel to the x-side
Corner column
Column distance x |
Distance in the x-direction between the edge of the slab and the nearest face of the column. |
Column distance y |
Distance in the y-direction between the edge of the slab and the nearest face of the column. |
Angle of edge with x-axis
|
Angle of the edge of the slab with the x-axis. |
Angle of edge with y-axis |
Angle of the edge of the slab with the y-axis. |
Central column
No position definition is needed
Hole position
If you check "Hole" in the Column type group, the following positions have to be defined.
Hole distance x |
Distance in the x-direction between the hole and the centre of the column. |
Hole distance y |
Distance in the y-direction between the hole and the centre of the column. |
Section groups
Plate data
Thickness of plate |
Thickness of the plate at the critical perimeter. Default value: the thickness of the plate. |
Concrete |
Column head data
Column head
|
Check this box to define a column head. |
Type of depth |
Select the type of the column head. Prismatic and Pyramidal are for rectangular columns, cylindrical and conical are for circular columns. |
Depth of the head Width of the head Lx of the head Lyof the head |
Depending on the column head type the depth and width of the column head can be defined using the appropriate fields. |
Loads
This tab shows either (i) the load imported from the model of the analysed structure, or (ii) the manually defined load in the assessed point. This is controlled by the item User loads in the Punching shear data.
If the load from the model is used, this tab shows all available load cases or combinations defined in the project.
If user load is used, the table contains the user-defined loads. Two buttons below the table makes it possible to add a new combination or to delete the existing one.
qd |
Distributed load (2D) on the slab of the appropriate load case/combination. It is used to correct Vd › punching force VSdpunch. |
VSd |
Concentrated load causing the punching force. For a support this is the reaction force. For a column it is its normal force that works on the slab. |
mSdx |
Minimum bending moment per unit length in the x-direction in the slab corresponding to the appropriate load case/combination. |
mSdy |
Minimum bending moment per unit length in the y-direction in the slab corresponding to the appropriate load case/combination. |
The sign convention can be read from the attached picture.
Main reinforcement
Note: This tab is not available for CSN/STN.
This tab shows the amount of longitudinal reinforcement in the plate near the node that is investigated.
Profile, Angle and Distance groups
The values are determined in the following way:
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Current available results for required reinforcement areas calculated in centroids of finite elements are used. This means that load cases or combinations considered during the punching shear check do not have any effect on the amount of reinforcement.
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Only results in finite elements whose centroid is closer than 1.5 m from the assessed node are taken into account.
Maximum value of reinforcement amount is used.
Area group
This group contains the calculated values of necessary reinforcement per unit of length in the appropriate layer.
Design of reinforcement
The contents of this tab may be different for different standards.
Loads group
The required load case / combination can be selected in the list of defined load cases / combinations. Results of punching shear check are displayed on the screen.
Critical section group
Detailed explanation of individual parameters is given in appropriate standards and in the theoretical manual.
The button [Calculation] performs the re-calculation for the current load case / combination.
Reinforcement for punching
Note: This tab is available only for CSN/STN.
This dialogue enables you to define shear reinforcement for punching shear. It is possible to input bent-up bars and links (stirrups). Bent-up bars are defined by their number, links by the number of rows.
Reinforcement group
Steel
|
Definition of the type of reinforcement steel. |
Number of rows |
Defines the total number of rows of shear reinforcement. For links it is the number of rows of links bordering the critical sections. For bent-up bars it is the number of their various types. These may differ in profile and steel and also position and number. |
Type of reinforcement |
The required type of reinforcement can be selected here. |
Angle of bent-up bars |
(accessible for bent-up only, links are assumed perpendicular to the middle plane) The angle between the bent-up and the plate surface. |
End of stirrups |
(accessible for links only) The standard distinguishes between welded links and links with anchor hooks. |
Load group
The required load case / combination may be selected here. The selected load case / combination is used for the design of punching shear reinforcement.
Reinforcement row group
One tab opens for each row of reinforcement.
Bars diameter
|
Defines the diameter of the reinforcement bars. |
Distance between bars |
Distance between bars. Note: The distance of bars is measured from centre-to-centre of the bar. |
Concrete cover top |
Concrete cover at the top surface. It influences whether the row is considered in the calculation. |
Concrete cover bottom
|
Analogous to the item above. |
As required |
The reinforcement area that is necessary to transfer the relative shear force. |
Reinforcement areas |
The reinforcement area calculated from the input parameters. |
Position of reinforcement from column face |
Defines the distance of the reinforcement bars from the column surface. For bent-up bars it is the distance of bent-up foot from the column face. For links it is the distance between the link axis and the column face. |
Set optimal position |
Opens a dialogue that calculates an optimal position of the reinforcement. The position is calculated in accordance with the provision defined in art. 5.5.6.14 of the standard. |
Check
Note: This tab is available only for CSN/STN.
This tab can be used to assess punching shear including the reinforcement.
Load group
The required load case / combination may be selected here. The selected load case / combination is used for the design of punching shear reinforcement.
Total design tab
This tab contains the overall evaluation. The worst critical section is automatically found and checked. Maximal punching shear force qd max and the ultimate punching shear force qu are listed including the critical section where these values were found.
Critical section tabs
Detailed results can be scrutinised in the tabs for individual sections.
hs
|
Plate thickness. |
Mcdx, Mcdy
|
Moments recalculated to the centroid of the critical section. |
ucrx, urcy
|
Length of the critical section. |
ucr
|
Total length of the critical section. |
qqd
|
Shear forces effects. |
qxmd, qymd
|
Moment effects. |
qbu
|
Shear force transferred by concrete. |
qsu
|
Shear force transferred by the reinforcement. |
[List qsu]
|
Lists the effectiveness of reinforcement for individual sections in accordance with the standard. The list specifies the distance where the reinforcement can be placed in order to be effective. |