D8.G.3 Design Parameters
Parameter Name | Default Value | Description |
---|---|---|
CODE | - |
Must be specified as IS13920 1993 準拠する設計コード。「TR.53.2 コンクリート設計パラメータの設定」を参照してください。 |
BRACING | 0.0 |
Beam Design
Column Design: Correspond to the terms "Braced" and "Unbraced" described in Notes 1, 2, and 3 of Clause 39.7.1 of IS456:2000.
|
DEPTH | YD | Total depth to be used for design. This value defaults to YD (depth of section in Y direction) as provided under MEMBER PROPERTIES. |
CLEAR |
25 mm 40 mm |
For beam members. For column members |
COMBINE | 0.0 |
Default value means there will be no member combination.
|
EFACE | 0.0 |
Face of support location at end of beam. The parameter can also be used to check against shear at any point from the end of the member. |
ELZ | 1.0 | Ratio of effective length to actual length of column about major axis. |
ELY | 1.0 | Ratio of effective length to actual length of column about minor axis. |
ENSH | 0.0 |
Perform shear check against enhanced shear strength as per Cl. 40.5 of IS456:2000.
|
EUDL | None | Equivalent u.d.l on span of the beam. This load value must be the unfactored load on span. During design the load value is multiplied by a factor 1.2. If no u.d.l is defined factored shear force due to gravity load on span will be taken as zero. No elastic or plastic moment will be calculated. Shear design will be performed based on analysis result.(Refer note) |
FYMAIN | 415 N/mm2 | Yield Stress for main reinforcing steel. |
FYSEC | 415 N/mm2 | Yield Stress for secondary reinforcing steel. |
FC | 30 N/mm2 | Concrete Yield Stress. |
GLD | None |
Gravity load number to be considered for calculating equivalent u.d.l on span of the beam, in case no EUDL is mentioned in the input. This load case can be any static load case containing MEMBER LOAD on the beam which includes UNI, CON, LIN and TRAP member loading. CMOM member loading is considered only when it is specified in local direction. FLOOR LOAD is also considered. The load can be primary or combination load. For combination load only load numbers included in load combination is considered. The load factors are ignored. Internally the unfactored load is multiplied by a factor 1.2 during design. If both EUDL and GLD parameters are mentioned in the input mentioned EUDL will be considered in design CMOM member loading in global direction is not considered. UMOM member loading is not considered. |
HLINK | Spacing of longitudinal bars measured to the outer face | Longer dimension of the rectangular confining hoop measured to its outer face. It shall not exceed 300 mm as per Cl. 7.4.8. If the HLINK value as provided in the input file does not satisfy the clause the value will be internally assumed as the default one. This parameter is valid for rectangular column. |
IPLM | 0.0 |
Default value calculates elastic/plastic hogging and sagging moments of resistance of beam at its ends.
|
IMB | 0.0 |
Default value calculates elastic/plastic hogging and sagging moments of resistance of beam at its ends.
|
MINMAIN | 10 mm | Minimum main reinforcement bar size. |
MAXMAIN | 60 mm | Maximum main reinforcement bar size. |
MINSEC | 8 mm | Minimum secondary reinforcement bar size. |
MAXSEC | 12 mm | Maximum secondary reinforcement bar size. |
PLASTIC | 0.0 |
Default value calculates elastic hogging and sagging moments of resistance of beam at its ends.
|
RATIO | 4.0 | Maximum percentage of longitudinal reinforcement in columns. |
REINF | 0.0 |
0.0 = Tied column (default) 1.0 = spiral reinforcement |
RENSH | 0.0 |
Distance of the start or end point of the member from its nearest support. This parameter is used only when a span of a beam is subdivided into two or more parts. Refer to Notes for IS456 Design Parameters. |
RFACE | 4.0 |
4.0 = longitudinal reinforcement in column is arranged equally along four faces. 2.0 invokes two faced distribution about major axis. 3.0 invokes two faced distribution about minor axis. |
SFACE | 0.0 |
Face of support location at start of beam. It is used to check against shear at the face of the support in beam design. The parameter can also be used to check against shear at any point from the start of the member.* |
SPSMAIN | 25 mm | Minimum clear distance between main reinforcing bars in beam and column. For column center to center distance between main bars cannot exceed 300 mm. |
TORISION | 0.0 |
0.0 = torsion to be considered in beam design. 1.0 = torsion to be neglected in beam design. |
TRACK | 0.0 | |
ULY | 1.0 | Ratio of unsupported length to actual length of column about minor axis. |
ULZ | 1.0 | Ratio of unsupported length to actual length of column about major axis. |
WIDTH | ZD | Width to be used for design. This value defaults to ZD as provided under MEMBER PROPERTIES. |
Bar combination has been introduced for detailing. Please refer D8.G.6 Bar Combination for details.
* EFACE and SFACE command is not valid for member combination.
** IPLM and IMB commands are not valid for member combination. These commands are ignored for members forming physical member.
*** The purpose of COMBINE command is the following:
-
If a beam spanning between two supports is subdivided into many sub-beams this parameter will combine them into one member. It can also be used to combine members to form one continuous beam spanning over more than two supports.
-
When two or more members are combined during design plastic or elastic moments will be calculated at the column supports. At all the intermediate nodes (if any) this calculation will be ignored.
-
It will calculate sectional forces at 13 sections along the length of the combined member.
-
It will calculate critical loads (similar to that of Design Load Summary) for all active load cases during design. Beams will be combined only when DESIGN BEAM command is issued.
The following lines should be satisfied during combination of members:
-
Members to be combined should have same sectional properties if any single span between two column supports of a continuous beam is subdivided into several members.
-
Members to be combined should have same constants (E, Poi ratio, alpha, density, and beta angle)
-
Members to be combined should lie in one straight line.
-
Members to be combined should be continuous.
-
Vertical members (i.e., columns) cannot be combined.
-
Same member cannot be used more than once to form two different combined members.
-
The maximum number of members that can be combined into one member is 299.
ENSH and RENSH parameters will have to be provided (as and when necessary) even if physical member has been formed.
D8.B.3.1 Example
The following lines show a standard example for design to be performed in IS 13920 1993.
STAAD SPACE
UNIT METER MTON
JOINT COORDINATES
…
MEMBER INCIDENCES
…
MEMBER PROPERTY INDIAN
…
CONSTANTS
…
SUPPORTS
…
DEFINE 1893 LOAD
ZONE 0.05 I 1 K 1 B 1
SELFWEIGHT
JOINT WEIGHT
…
LOAD 1 SEISMIC LOAD IN X DIR
1893 LOAD X 1
LOAD 2 SEISMIC LOAD IN Z DIR
1893 LOAD Z 1
LOAD 3 DL
MEMBER LOAD
…… UNI GY -5
LOAD 4 LL
MEMBER LOAD
……. UNI GY -3
LOAD COMB 5 1.5(DL+LL)
3 1.5 4 1.5
LOAD COMB 6 1.2(DL+LL+SLX)
1 1.2 3 1.2 4 1.2
LOAD COMB 7 1.2(DL+LL-SLX)
1 1.2 3 1.2 4 -1.2
LOAD COMB 8 1.2(DL+LL+SLZ)
2 1.2 3 1.2 4 1.2
LOAD COMB 9 1.2(DL+LL-SLZ)
2 1.2 3 1.2 4 -1.2
PDELTA ANALYSIS
LOAD LIST 5 TO 9
START CONCRETE DESIGN
CODE IS13920 1993
UNIT MMS NEWTON
FYMAIN 415 ALL
FC 20 ALL
MINMAIN 12 ALL
MAXMAIN 25 ALL
TRACK 2.0 ALL
*** Unfactored gravity load on members 110 to 112 is 8 t/m (DL+LL) i.e., 78.46 New/mm
EUDL 78.46 MEMB 110 TO 112
** Members to be combined into one physical member
COMBINE 3.0 MEMB 110 TO 112
*** Plastic moment considered
PLASTIC 1.0 MEMB 110 TO 112
DESIGN BEAM 110 TO 112
DESIGN COLUMN …
END CONCRETE DESIGN
FINISH