|
(a) (b) (c) |
|
(d) (e) |
Figure 1. Types of designs for the joint of rigid column bases without wing plates and cantilever stiffeners. |
The Rigid Column Bases mode enables to design and check the load-bearing capacity of joints of the column bases which provide a rigid column-to-foundation connection. This mode comprises a wide range of designs for this type of joints, such as:
There are no additional details reinforcing the column base in the designs of the first four types of column bases. Such bases are usually designed for buildings without cranes and for buildings with small capacity cranes. Column bases with wing plates and anchor bolts have additional structural elements (wing plates and cantilever stiffeners) which provide a more uniform distribution of stresses in concrete of the foundation under the base plate.
This mode performs the following checks in compliance with the selected building code:
|
(a) (b) (c) |
|
(d) (e) |
Figure 1. Types of designs for the joint of rigid column bases without wing plates and cantilever stiffeners. |
|
(a) (b) (c) |
|
(d) (e) (f) (g) |
|
(h) (i) |
Figure 2. Types of designs for the joints of rigid column bases with wing plates and cantilever stiffeners. |
|
(a) (b) |
Figure 3. Types of designs for the joints of rigid column bases with external wing plates. |
The Rigid Column Bases dialog box contains the following tabs: Configuration, Forces, Structure, Welding, Drawing, and Interaction Curves.
The user has to specify the initial data for the calculation in the Configuration tab (the column section, steel grade for the column, class of concrete of the foundation, service factor and importance factor). The type of the column section can be selected by clicking the respective button: Rolled I-section or Welded I-section. The interface of this tab depends on this choice. If a rolled I-section is selected as the column cross-section type, you then have to select an assortment and the profile number in this assortment in the Select profile dialog box, which can be invoked by clicking the Select the column section button.
When a welded I-section is selected as the column cross-section type,
you have to specify the sizes of the column cross-section: the height,
hw, and the thickness,
tw, of the web; the
width, bf, and the
thickness, tf, of
the flanges. The sizes of the column cross-section should be entered in
the table in millimeters. It should be noted that the thickness of the
web and of the flange can be either entered manually or selected from
the drop-down lists, which contain the set of thickness values according
to the assortment of sheet and plate steel. The column cross-section can
be checked in the Preview window,
which can be invoked by clicking the Preview
button (
).
When the analysis and design are performed according to EN 1993-1-1:2005 and EN 1993-1-8:2005, the Configuration tab of the Rigid Column Bases mode also contains the Grout type drop-down list and the Grout thickness field, which are used to enter the respective information about the grout under the base plate of the column base joint.
Materials used for design and analysis of a rigid column base joint can be selected from the Steel and Concrete drop-down lists, which suggest the steel grades for steel members of the column base joint and concrete classes for the foundation.
You can enter the service factor for column in the respective text field,
or it can be selected in the Service Factor
dialog box after clicking the nearby button (
).
The service factor of the base plate of the column base is calculated automatically in this mode. The user has to specify the service factor not for the base plate but for the column.
The importance factor which will be further multiplied by the design values of all internal forces for all design combinations of loadings acting in the column base section has to be specified in the Importance factor drop-down list in this tab. If the values of the internal forces in the column base section have been obtained based on the results of the analysis of the system accounting for the importance factor (for example, when the design values of the applied loads were obtained taking into account this factor), the value equal to one has to be selected in the Importance factor drop-down list.
Clicking the Stamp button opens a Stamp dialog box, which enables to fill in the stamp of the drawing used in the draft of the design of the rigid column base joint. The Save template button enables to save the entered data as a template of the stamp for the current session of the application. The saved template can be used both in the current and in other modes of the application by clicking the Load template button.
The Welding tab enables to specify
the parameters of the welded connections for the joint. The
Properties of joint contains drop-down lists which are used
to select the type and method of welding, and specify the position of
the weld. This mode implements the following methods of welding in compliance
with Table 34* of SNiP II-23-81* (Table 36 of SP 53-102-2004,
Table 38 of SP 16.13330, Table 1.12.2 of DBN B.2.6-163:2010,
or Table 16.2 of DBN B.2.6-198:2014): manual welding, semiautomatic
welding with solid wire less than 1.4 mm in diameter, automatic and
semiautomatic welding with the electrode wire 1.4 to 2.0 mm in diameter,
automatic welding with the electrode wire 3 to 5 mm in diameter,
and semiautomatic welding with flux-cored wire. The position of weld can
be underhand, flat, horizontal, vertical or overhead. The Properties
of welding materials group displays values of the design resistance
of the fillet welds for conventional shear of the weld metal, Rwf,
and of the characteristic resistance of the weld metal, Rwun.
These values can be specified in the Materials
for Welding dialog box, which is invoked by clicking the button 
.
The Forces tab is used to specify the internal forces acting in the joint of the column base: an axial force, N; bending moments in two planes, My and Mz; their respective shear forces, Qy and Qz.
To set a proper orientation of the specified internal forces with respect to the principal axes of inertia of the cross-sections that meet in a joint, each bar of the joint is referred to a local coordinate system, xyz. The application implements the following orientation of the local coordinate systems of the bars: the x – x axis goes from the beginning of a bar (its start node) to its end (its end node), the y – y and z – z axes (the principal central axes of inertia of the bar cross-section) make up a right-hand Cartesian coordinate system together with the x – x axis. The y – y axis is parallel to the XOY plane of the global coordinate system, and the z – z axis goes to the upper half-space.
The general case of the column loading, biaxial bending with compression or tension, is thus implemented. The drawing next to the table of internal forces defines the positive directions of internal forces in the sections of the column base members. Clicking the Add button adds a new row to the table of internal forces, where you have to enter the values of internal forces for the current combination of loads. There can be any number of design combinations of loads. Units of measurement for the internal forces acting in the joint are defined in the Units of Measurement tab of the Application Settings dialog box. The default units of measurement for axial and shear forces are tonnes, and for bending moments – tonne×meter. To change the plane of loading, use the respective button. This will transfer the values of My and Qy to the respective columns of the table for Mz and Qz, and vice versa.
The Structure tab contains a group of buttons to select a design for the joint of the rigid column base.
To perform a check (i.e. check the load-bearing capacity according to SNiP, SP, DBN of a known structural design of the column base, you have to specify all design parameters of the joint. The parameters include the sizes and thickness of structural members of the joint, diameters of anchor bolts, sizes which determine the mutual arrangement of members, leg lengths of welds, the number of bolts, the number of bolt rows, etc. The parameters of the joint are entered in the table on the right. The diameter, the steel grade, and the number of anchor bolts (for some types of bases) are selected from the special drop-down lists of the Anchor bolts group. The default units of linear measurement are millimeters.
Clicking the Design button drops down a menu. If the first item, All parameters are not specified, is selected, the automatic selection of all parameters of the joint design is performed and it is assumed that the parameters of the joint design are not specified (are equal to zero), and their previously specified values are ignored. If the Some parameters are specified menu item is selected, the program will automatically determine the values of the undefined (are equal to zero) parameters with fixed values of the specified parameters.
The automatic selection of the column base design was performed on the basis of the analysis of its sensitivity with respect to the variation of the controlled parameters of the joint taking into account the conditions of the adequate resistance and structural constraints defined by the standards (see General Information). The diameter of the anchor bolts and the thickness of the base plate, as well as the dimensions of the support base plate were the controlled parameters.
Clicking the Calculate button will perform the check of the load-bearing capacity of the specified joint members and of the connections between them according to SNiP, SP, DBN.
After clicking the Design or Calculate button the maximum utilization factor of restrictions (the most dangerous) will be displayed in the Kmax field located in the lower part of the dialog box, and the type of the standard check (strength, stability, local stability, etc.) in which this maximum took place will be indicated, and a drawing of the column base joint design of the MS stage will be generated.
A complete list of the performed checks can be obtained by clicking the Factors button. It will be displayed in the special Factors Diagram dialog box, where you can browse the values of all utilization factors of restrictions. The list of the load-bearing capacity checks of the members and connections of the joints of the rigid column bases performed by the application is given in the table below.
Clicking the Report button generates a report document which contains the initial data and the results of analysis.
No |
Check |
Type of base |
SNiP II-23-81* |
SP 53-102-2004 |
SP 16.13330 |
DBN B.2.6-163:2010 |
DBN B.2.6-198:2014 |
|---|---|---|---|---|---|---|---|
1 |
Bending resistance of the base plate under normal stresses in areas supported along the contour |
Fig. 2, a, b, h, i; Fig. 3 |
Sec. 5.12, (28) |
Sec. 9.2.1, (35) |
Sec. 8.6.2, (101), (103) |
Sec.1.7.2, (1.7.1), Annex N, (N.2), Table N.2 |
Sec. 11.2, (11.1), Sec. М, (М.1), (М.2) Table М.2 |
2 |
Bending resistance of the base plate under normal stresses in areas supported on three sides |
Fig. 2; 3 |
Sec. 5.12, (28) |
Sec. 9.2.1, (35) |
Sec. 8.6.2, (101), (104) |
Sec.1.7.2, (1.7.1), Annex N, (N.2), Table N.2 |
Sec. 11.2, (11.1), Sec. М, (М.1), (М.2) Table М.2 |
3 |
Bending resistance of the base plate under normal stresses in areas supported on two sides meeting at an angle |
Fig. 2, a, b, g |
Sec. 5.12, (28) |
Sec. 9.2.1, (35) |
Sec. 8.6.2, (101), (104) |
Sec. 1.7.2, (1.7.1), Annex N, (N.2), Table N.2 |
Sec. 11.2, (11.1), Sec. М, (М.1), (М.2) Table М.2 |
4 |
Bending resistance of the base plate under normal stresses in cantilever areas of the plate |
Fig. 3 |
Sec. 5.12, (28) |
Sec. 9.2.1, (35) |
Sec. 8.6.2, (101), (102) |
Sec. 1.7.2, (1.7.1), Annex N, (N.1) |
Sec. 11.2, (11.1), Sec. М, (М.1), (М.2) Table М.2 |
5 |
Bending resistance of the base plate under normal stresses in free trapezoid areas of the plate |
Fig. 1; 2; 3 |
Sec. 5.12, (28) |
Sec. 9.2.1, (35) |
Sec. 8.6.2, (101) |
Sec. 1.7.2, (1.7.1) |
Sec. 11.2, (11.1) |
6 |
Resistance of the foundation concrete in local bearing under the plate |
Fig. 2; 3 |
|
|
|
|
|
7 |
Resistance of the welded connection between the column and the base plate |
Fig. 1 |
Sec. 11.2*, (120)-(121) |
Sec. 15.1.16, (155), (156) |
Sec. 14.1.16, (176), (177) |
Sec. 1.12.1.16, (1.12.2), (1.12.3) |
Sec. 16.1.16, (16.2), (16.3) |
8 |
Resistance of the welded connection between the wing plate and column flanges |
Fig. 2, a, b, h, i; Fig. 3 |
Sec. 11.2*, (120)-(121) |
Sec. 15.1.16, (155), (156) |
Sec. 14.1.16, (176), (177) |
Sec. 1.12.1.16, (1.12.2), (1.12.3) |
Sec. 16.1.16, (16.2), (16.3) |
9 |
Resistance of the welded connection between the wing plate and the base plate |
Fig. 2, a, b, h, i; Fig. 3 |
Sec. 11.2*, (120)-(121) |
Sec. 15.1.16, (155), (156) |
Sec. 14.1.16, (176), (177) |
Sec. 1.12.1.16, (1.12.2), (1.12.3) |
Sec. 16.1.16, (16.2), (16.3) |
10 |
Resistance of the welded connection between the cantilever stiffener and column flanges |
Fig. 2, c, d, e, f; Fig. 3 |
Sec. 11.4, (33) |
Sec. 15.1.15, (38) |
Sec. 14.1.15, (44) |
Sec. 1.12.1.15, (1.5.4) |
Sec. 16.1.15, (9.4) |
11 |
Resistance of the welded connection between the cantilever stiffener and the wing plate |
Fig. 2, a, b, g |
Sec. 11.5, (120)-(123), (126) |
Sec. 15.1.16, (155), (156), Sec.15.1.17, (157), (158), Sec. 15.1.19, (161) |
Sec. 14.1.16, (176), (177), Sec. 14.1.17, (178), (179), Sec. 14.1.19, (182), (183) |
Sec. 1.12.1.16, (1.12.2), (1.12.3), Sec. 1.12.1.17, (1.12.4), (1.12.5), Sec. 1.12.1.19, (1.12.8), (1.12.9) |
Sec. 16.1.16, (16.2), (16.3), Sec. 16.1.17, (16.4), (16.5), Sec. 16.1.19, (16.8), (16.9) |
12 |
Resistance of the anchor bolts |
Fig. 1; 2; 3 |
Sec. 11.7*, (129), Sec. 11.8, (130) |
Sec. 15.2.9, (167), Sec. 15.2.10, (168) |
Sec. 14.2.9, (186)-(188), Sec. 14.2.10, (189) |
Sec. 1.12.2.9, (1.12.12) –(1.12.14), Sec. 1.12.2.10, (1.12.15), |
Sec. 16.2.9, (16.12) –(16.14), Sec. 16.2.10, (16.15) |
13 |
Bending resistance of the wing plate under shear stresses |
Fig. 3 |
Sec. 5.12, (29) |
Sec. 9.2.1, (36) |
Sec. 8.2.1, (42) |
Sec. 1.5.2.1, (1.5.2) |
Sec. 9.2.1, (9.2) |
14 |
Bending resistance of the wing plate under reduced stresses |
Fig. 3 |
Sec. 5.14*, (33) |
Sec. 9.2.1, (38) |
Sec. 8.2.1, (44) |
Sec. 1.5.2.1, (1.5.4) |
Sec. 9.2.1, (9.4) |
15 |
Bending resistance of the wing plate under normal stresses |
Fig. 3 |
Sec. 5.12, (28) |
Sec. 9.2.1, (35) |
Sec. 8.2.1, (41) |
Sec. 1.5.2.1, (1.5.1) |
Sec. 9.2.1, (9.1) |
16 |
Resistance of the cantilever stiffener under shear stresses |
Fig. 3 |
Sec. 5.12, (29) |
Sec. 9.2.1, (36) |
Sec. 8.2.1, (42) |
Sec. 1.5.2.1, (1.5.2) |
Sec. 9.2.1, (9.2) |
17 |
Resistance of the cantilever stiffener under reduced stresses |
Fig. 3 |
Sec. 5.14*, (33) |
Sec. 9.2.1, (38) |
Sec. 8.2.1, (44) |
Sec. 1.5.2.1, (1.5.4) |
Sec. 9.2.1, (9.4) |
18 |
Bending resistance of the cantilever stiffener under normal stresses |
Fig. 3 |
Sec. 5.12, (28) |
Sec. 9.2.1, (35) |
Sec. 8.2.1, (41) |
Sec. 1.5.2.1, (1.5.1) |
Sec. 9.2.1, (9.1) |
19 |
Bending resistance of the anchor plate under shear stresses |
Fig. 3 |
Sec. 5.12, (29) |
Sec. 9.2.1, (36) |
Sec. 8.2.1, (42) |
Sec. 1.5.2.1, (1.5.2) |
Sec. 9.2.1, (9.2) |
20 |
Bending resistance of the anchor plate under reduced stresses |
Fig. 3 |
Sec. 5.14*, (33) |
Sec. 9.2.1, (38) |
Sec. 8.2.1, (44) |
Sec. 1.5.2.1, (1.5.4) |
Sec. 9.2.1, (9.4) |
21 |
Bending resistance of the anchor plate under normal stresses |
Fig. 3 |
Sec. 5.12, (28) |
Sec.9.2.1, (35) |
Sec. 8.2.1, (41) |
Sec.1.5.2.1, (1.5.1) |
Sec. 9.2.1, (9.1) |
Notes:
|
|||||||
Once you switch to the Drawing tab, the application performs a check and design of the joint, similarly to the Calculate mode. If the results of analysis of the parameters of the joint members do not contradict the structural and standard requirements, a drawing of the joint design of the MS stage will be generated.
The upper part of the Drawing
tab contains a toolbar with buttons (
) which enable
to zoom the image in or out, save the drawing as DWG (DXF) for AutoCAD,
or print it out.
The curves enclosing an area of the load-bearing capacity of the specified (or selected) design of the rigid column base joint under various pairs of internal forces which can arise in the column base section are plotted in the Interaction Curves tab.
Click the Show button to generate such a curve. A drop-down list serves to select a pair of variable internal forces, and all other forces are taken as values specified in the Fixed values group.
Using your mouse pointer, you can explore the area of the load-bearing capacity of the rigid base joint shown in the graph. Every position of the pointer corresponds to a pair of numerical values of the variable forces; their values are displayed in the respective fields. Clicking the right mouse button will display the list of performed checks and values of the factors for the set of forces corresponding to the current position of the pointer in the plot area of the interaction curve.
The maximum value of the utilization factor of restrictions Kmax,
that corresponds to the current values of the internal forces will be
displayed in the Factor field,
and the name of the type of check in which it takes place will be output
in the Critical factor field.
When the pointer is placed outside the area of the load-bearing capacity
where Kmax > 1,
a warning sign is displayed next to the name of the type of check 
.
The dialog box also contains three buttons: 
, which enable to perform the following operations:
— if the
forces are specified, clicking this button will draw the points the coordinates
of which in the area of the load-bearing capacity correspond to these
forces;
— drawing
a convex hull of the points specified above, i.e. an entire set of points
which may result from a linear combination of specified forces, including
their incomplete values;
— saving the
forces that can lead to Kmax=1
in a text file (this file can be imported into other programs for further
analysis).
