Seismic Load Cases

ASCE 7-10 / ASCE 7-05/ IBC 2006/2009 Equivalent Lateral Force

Setting	Description
Load Case	States the Label of the load case being defined.
Load Case Provisions	The provisions for calculating seismic forces vary depending on whether the generated forces are to be used for the calculation of drift, member forces or foundation forces. Load cases can be defined for each provision, allowing for the simultaneous investigation of the three conditions. See building code for more information.
Direction	Use the Direction box to indicate the direction of the force (X, Y, or both) by clicking on the corresponding box so that the box is marked. One load case will be generated for each direction at which the force acts.
Eccentricity	You may choose to include the effects of accidental torsion in the application of the seismic forces. The value of eccentricity used is specified in Loads - Masses. A default value of 5% is assumed by the program. See building code for more information.
Structural Period	This is the period of the building which can be obtained through eigenvalue analysis or through the specified code equations. See building code for more information.
R	The response modification coefficient is defined by and specified in the appropriate code. See building code for more information.
Seismic Design Category	The Seismic Design Category is specified in IBC Table 1613.5.6(1) and Table 1613.5.6(2). It is based on the Occupancy Category, SDS, and SD1 and can be determined directly from the user input. You can either designate that the program determine the Seismic Design Category or else enter it directly; this is only necessary if you want to over-ride what the program would otherwise select.
Occupancy Category	Occupancy Category determined according to IBC Table 1604.5.
Site Class	The Site Class is specified in IBC Table 1613.5.5. It is based on the Soil profile and properties.
Ss	Ss is the mapped spectral accelerations for short periods as determined in IBC Section 1613.5.1. Values are given in Figures 1613.5(1) through 1613.5(14)
S1	S1 is the mapped spectral accelerations for a 1-second period as determined in IBC Section 1613.5.1. Values are given in Figures 1613.5(1) through 1613.5(14)
TL	Long-period transition period(s) given in Figures from 22-15 to 22-20 in ASCE 7-05.
Importance Factor	The Importance Factor is defined by and specified in the appropriate code. See the building code for more information.
Generate Additional Load Cases for Analysis with Tension-Only Members	RAM Frame utilizes a nonlinear analysis algorithm to keep track of tension-only members during solution of the structural model under applied loads. Since the process has a nonlinear (iterative) nature, analysis results can not be simply superposed with other results as in load combination option in RAM Frame. Therefore, each lateral load case (wind or seismic) are solved separately. Since the direction of the lateral loads become important in an iterative analysis, RAM Frame provides an option such that additional load cases can be created upon user request. When Generate Additional Load Cases for Analysis with Tension-Only Members in generating lateral load cases (wind and seismic load cases only) is invoked, additional load cases are created. For instance, there are 12 load cases generated for a regular IBC 2000 (ASCE 7-98) Wind load case. If this box is checked, the number of the load cases becomes 22. Additional load cases are created to account for directional effects of applied loads so that the most severe loading case is captured. Conceptual example of additional load cases for tension-only members
Orthogonal Effects (100/30)	Orthogonal load cases can be created based on the 100%/30% requirement of some building codes: loads are applied 100% in one direction and 30% in the orthogonal direction at the same time. This is only implemented for US seismic load cases. To invoke this feature, select the Consider Orthogonal Effects (100/30) option when generating seismic load cases. Note that invoking this option substantially increases the number of load cases created. For instance, a total of 36 different load cases (40 if Generate Additional Load Cases for Analysis with Tension-Only Members is also checked) are created for IBC 2000 seismic load case. The following figure shows an example of the generated load cases. Generated load cases based on 100%/30% rule and additional cases for tension-only members

ASCE 7-02/IBC 2003 Equivalent Lateral Force

Setting	Description
Load Case	States the Label of the load case being defined.
Load Case Provisions	The provisions for calculating seismic forces vary depending on whether the generated forces are to be used for the calculation of drift, member forces or foundation forces. Load cases can be defined for each provision, allowing for the simultaneous investigation of the three conditions. See building code for more information.
Direction	Use the Direction box to indicate the direction of the force (X, Y, or both) by clicking on the corresponding box so that the box is marked. One load case will be generated for each direction at which the force acts.
Eccentricity	You may choose to include the effects of accidental torsion in the application of the seismic forces. The value of eccentricity used is specified in Loads - Masses. A default value of 5% is assumed by the program. See building code for more information.
Structural Period	This is the period of the building which can be obtained through eigenvalue analysis or through the specified code equations. See building code for more information.
R	The response modification coefficient is defined by and specified in the appropriate code. See building code for more information.
Seismic Design Category	The Seismic Design Category is specified in IBC Table 1613.5.6(1) and Table 1613.5.6(2). It is based on the Occupancy Category, SDS, and SD1 and can be determined directly from the user input. You can either designate that the program determine the Seismic Design Category or else enter it directly; this is only necessary if you want to over-ride what the program would otherwise select.
Site Class	The Site Class is specified in IBC Table 1615.1.1. It is based on the Soil profile and properties.
Ss	Ss is the mapped spectral accelerations for short periods as determined in IBC Section 1615.1. Values are given in Figures 1615(1) through 1615(10).
S1	S1 is the mapped spectral accelerations for a 1-second period as determined in IBC Section 1615.1. Values are given in Figures 1615(1) through 1615(10).
Importance Factor	The Importance Factor is defined by and specified in the appropriate code. See the building code for more information.
Generate Additional Load Cases for Analysis with Tension-Only Members	RAM Frame utilizes a nonlinear analysis algorithm to keep track of tension-only members during solution of the structural model under applied loads. Since the process has a nonlinear (iterative) nature, analysis results can not be simply superposed with other results as in load combination option in RAM Frame. Therefore, each lateral load case (wind or seismic) are solved separately. Since the direction of the lateral loads become important in an iterative analysis, RAM Frame provides an option such that additional load cases can be created upon user request. When Generate Additional Load Cases for Analysis with Tension-Only Members in generating lateral load cases (wind and seismic load cases only) is invoked, additional load cases are created. For instance, there are 12 load cases generated for a regular IBC 2000 (ASCE 7-98) Wind load case. If this box is checked, the number of the load cases becomes 22. Additional load cases are created to account for directional effects of applied loads so that the most severe loading case is captured. Conceptual example of additional load cases for tension-only members
Orthogonal Effects (100/30)	Orthogonal load cases can be created based on the 100%/30% requirement of some building codes: loads are applied 100% in one direction and 30% in the orthogonal direction at the same time. This is only implemented for US seismic load cases. To invoke this feature, select the Consider Orthogonal Effects (100/30) option when generating seismic load cases. Note that invoking this option substantially increases the number of load cases created. For instance, a total of 36 different load cases (40 if Generate Additional Load Cases for Analysis with Tension-Only Members is also checked) are created for IBC 2000 seismic load case. The following figure shows an example of the generated load cases. Generated load cases based on 100%/30% rule and additional cases for tension-only members

IBC 2000 Equivalent Lateral Force

Setting	Description
Load Case	States the Label of the load case being defined.
Load Case Provisions	The provisions for calculating seismic forces vary depending on whether the generated forces are to be used for the calculation of drift, member forces or foundation forces. Load cases can be defined for each provision, allowing for the simultaneous investigation of the three conditions. See building code for more information.
Direction	Use the Direction box to indicate the direction of the force (X, Y, or both) by clicking on the corresponding box so that the box is marked. One load case will be generated for each direction at which the force acts.
Eccentricity	You may choose to include the effects of accidental torsion in the application of the seismic forces. The value of eccentricity used is specified in Loads - Masses. A default value of 5% is assumed by the program. See building code for more information.
Structural Period	This is the period of the building which can be obtained through eigenvalue analysis or through the specified code equations. See building code for more information.
R	The response modification coefficient is defined by and specified in the appropriate code. See building code for more information.
Seismic Design Category	The Seismic Design Category is specified in IBC Table 1613.5.6(1) and Table 1613.5.6(2). It is based on the Occupancy Category, SDS, and SD1 and can be determined directly from the user input. You can either designate that the program determine the Seismic Design Category or else enter it directly; this is only necessary if you want to over-ride what the program would otherwise select.
Site Class	The Site Class is specified in IBC Table 1615.1.1. It is based on the Soil profile and properties.
Ss	Ss is the mapped spectral accelerations for short periods as determined in IBC Section 1615.1. Values are given in Figures 1615(1) through 1615(10).
S1	S1 is the mapped spectral accelerations for a 1-second period as determined in IBC Section 1615.1. Values are given in Figures 1615(1) through 1615(10).
Importance Factor	The Importance Factor is defined by and specified in the appropriate code. See the building code for more information.
Generate Additional Load Cases for Analysis with Tension-Only Members	RAM Frame utilizes a nonlinear analysis algorithm to keep track of tension-only members during solution of the structural model under applied loads. Since the process has a nonlinear (iterative) nature, analysis results can not be simply superposed with other results as in load combination option in RAM Frame. Therefore, each lateral load case (wind or seismic) are solved separately. Since the direction of the lateral loads become important in an iterative analysis, RAM Frame provides an option such that additional load cases can be created upon user request. When Generate Additional Load Cases for Analysis with Tension-Only Members in generating lateral load cases (wind and seismic load cases only) is invoked, additional load cases are created. For instance, there are 12 load cases generated for a regular IBC 2000 (ASCE 7-98) Wind load case. If this box is checked, the number of the load cases becomes 22. Additional load cases are created to account for directional effects of applied loads so that the most severe loading case is captured. Conceptual example of additional load cases for tension-only members
Orthogonal Effects (100/30)	Orthogonal load cases can be created based on the 100%/30% requirement of some building codes: loads are applied 100% in one direction and 30% in the orthogonal direction at the same time. This is only implemented for US seismic load cases. To invoke this feature, select the Consider Orthogonal Effects (100/30) option when generating seismic load cases. Note that invoking this option substantially increases the number of load cases created. For instance, a total of 36 different load cases (40 if Generate Additional Load Cases for Analysis with Tension-Only Members is also checked) are created for IBC 2000 seismic load case. The following figure shows an example of the generated load cases. Generated load cases based on 100%/30% rule and additional cases for tension-only members

UBC 94/97 Seismic Static Force Procedure

Setting	Description
Load Case	States the Label of the load case being defined.
Direction	Use the Direction box to indicate the direction of the force (X, Y, or both) by clicking on the corresponding box so that the box is marked. One load case will be generated for each direction at which the force acts.
Eccentricity	You may choose to include the effects of accidental torsion in the application of the seismic forces. The value of eccentricity used is specified in Loads - Masses. A default value of 5% is assumed by the program. See building code for more information.
Structural Period	This is the period of the building which can be obtained through eigenvalue analysis or through the specified code equations. See building code for more information.
Zone	The seismic zone that the building is located in. This is used to determine which special seismic provisions in the UBC are applicable to the frame types designated.
R	The response modification coefficient is defined by and specified in the appropriate code. See building code for more information.
Soil	The Soil Profile Type is defined by and specified in the appropriate code. See the building code for more information.
Importance Factor	The Importance Factor is defined by and specified in the appropriate code. See the building code for more information.
Load Case Provisions	The provisions for calculating seismic forces vary depending on whether the generated forces are to be used for the calculation of drift, member forces or foundation forces. Load cases can be defined for each provision, allowing for the simultaneous investigation of the three conditions. See building code for more information.
Generate Additional Load Cases for Analysis with Tension-Only Members	RAM Frame utilizes a nonlinear analysis algorithm to keep track of tension-only members during solution of the structural model under applied loads. Since the process has a nonlinear (iterative) nature, analysis results can not be simply superposed with other results as in load combination option in RAM Frame. Therefore, each lateral load case (wind or seismic) are solved separately. Since the direction of the lateral loads become important in an iterative analysis, RAM Frame provides an option such that additional load cases can be created upon user request. When Generate Additional Load Cases for Analysis with Tension-Only Members in generating lateral load cases (wind and seismic load cases only) is invoked, additional load cases are created. For instance, there are 12 load cases generated for a regular IBC 2000 (ASCE 7-98) Wind load case. If this box is checked, the number of the load cases becomes 22. Additional load cases are created to account for directional effects of applied loads so that the most severe loading case is captured. Conceptual example of additional load cases for tension-only members
Orthogonal Effects (100/30)	Orthogonal load cases can be created based on the 100%/30% requirement of some building codes: loads are applied 100% in one direction and 30% in the orthogonal direction at the same time. This is only implemented for US seismic load cases. To invoke this feature, select the Consider Orthogonal Effects (100/30) option when generating seismic load cases. Note that invoking this option substantially increases the number of load cases created. For instance, a total of 36 different load cases (40 if Generate Additional Load Cases for Analysis with Tension-Only Members is also checked) are created for IBC 2000 seismic load case. The following figure shows an example of the generated load cases. Generated load cases based on 100%/30% rule and additional cases for tension-only members

Eurocode ENV1998-1-1:199

Setting	Description
Load Case	States the Label of the load case being defined.
Direction	Use the Direction box to indicate the direction of the force (X, Y, or both) by clicking on the corresponding box so that the box is marked. One load case will be generated for each direction at which the force acts.
Eccentricity	You may choose to include the effects of accidental torsion in the application of the seismic forces. The value of eccentricity used is specified in Loads - Masses. A default value of 5% is assumed by the program. See building code for more information.
Structural Period	This is the period of the building which can be obtained through eigenvalue analysis or through the specified code equations. See building code for more information.
Distribution Method	The generated base shear can be distributed up the height of the structure based on either the fundamental mode shape or relative to story height and mass (linear). Refer to the Eurocode ENV1998-1-1:1994 for more information on story shear distribution.
Behavior Factor	The response spectra from which the base shear is determined is modified to account for the material ductility which is represented by the Behavior Factor (q). Refer to the Eurocode ENV1998-1-1:1994 for additional information concerning the Behavior Factor.
Soil	The Soil Profile Type is defined by and specified in the appropriate code. See the building code for more information.
Generate Additional Load Cases for Analysis with Tension-Only Members	RAM Frame utilizes a nonlinear analysis algorithm to keep track of tension-only members during solution of the structural model under applied loads. Since the process has a nonlinear (iterative) nature, analysis results can not be simply superposed with other results as in load combination option in RAM Frame. Therefore, each lateral load case (wind or seismic) are solved separately. Since the direction of the lateral loads become important in an iterative analysis, RAM Frame provides an option such that additional load cases can be created upon user request. When Generate Additional Load Cases for Analysis with Tension-Only Members in generating lateral load cases (wind and seismic load cases only) is invoked, additional load cases are created. For instance, there are 12 load cases generated for a regular IBC 2000 (ASCE 7-98) Wind load case. If this box is checked, the number of the load cases becomes 22. Additional load cases are created to account for directional effects of applied loads so that the most severe loading case is captured. Conceptual example of additional load cases for tension-only members

NBCC-95 Seismic

Setting

Description

Load Case

States the Label of the load case being defined.

Direction

Use the Direction box to indicate the direction of the force (X, Y, or both) by clicking on the corresponding box so that the box is marked. One load case will be generated for each direction at which the force acts.

Eccentricity

You may choose to include the effects of accidental torsion in the application of the seismic forces. The value of eccentricity used is specified in Loads - Masses. A default value of 5% is assumed by the program. See building code for more information.

Structural Period

This is the period of the building which can be obtained through eigenvalue analysis or through the specified code equations. See building code for more information.

Force Modification Factor, R

The Force Modification Factor is defined and specified by NBCC-95. It is given in table 4.1.9.1.B and ranges from 1 to 4 with typical values of 3 or 4.

Seismic Importance Factor, I

The Seismic Importance Factor is defined and specified by the code.

Foundation Factor

The Foundation Factor is defined and specified by the NBCC-95 and is given in table 4.1.9.1.C. Values for the Foundation Factor range from 1.0 to 2.0.

Seismic Zones

Setting	Description
Za	acceleration related seismic zone as specified in NBCC-95.
Zv	velocity related seismic zone as specified in NBCC-95.

Generate Additional Load Cases for Analysis with Tension-Only Members

RAM Frame utilizes a nonlinear analysis algorithm to keep track of tension-only members during solution of the structural model under applied loads. Since the process has a nonlinear (iterative) nature, analysis results can not be simply superposed with other results as in load combination option in RAM Frame. Therefore, each lateral load case (wind or seismic) are solved separately.

Since the direction of the lateral loads become important in an iterative analysis, RAM Frame provides an option such that additional load cases can be created upon user request. When Generate Additional Load Cases for Analysis with Tension-Only Members in generating lateral load cases (wind and seismic load cases only) is invoked, additional load cases are created. For instance, there are 12 load cases generated for a regular IBC 2000 (ASCE 7-98) Wind load case. If this box is checked, the number of the load cases becomes 22. Additional load cases are created to account for directional effects of applied loads so that the most severe loading case is captured.

Conceptual example of additional load cases for tension-only members

NBCC-2005 Seismic

Setting

Description

Load Case

States the Label of the load case being defined.

Direction

Use the Direction box to indicate the direction of the force (X, Y, or both) by clicking on the corresponding box so that the box is marked. One load case will be generated for each direction at which the force acts.

Eccentricity

You may choose to include the effects of accidental torsion in the application of the seismic forces. The value of eccentricity used is specified in Loads - Masses. A default value of 5% is assumed by the program. See building code for more information.

Force Modification Factors

The following must be provided for both X-Dir and Y-Dir:

Setting	Description
Rd	Ductility related force modification factor, R_d, reflecting the capability of a structure to dissipate energy through inelastic behavior is required from the user for each direction. This factor is provided in Table 4.1.8.9.
Ro	Overstrength related force modification factor, R_o, accounting for the dependable portion of reserve strength in a structure is required from the user for each direction. This factor is provided in Table 4.1.8.9.

Structural Period

The fundamental period (Ta) is based on one of the following choices:

Clause (a): Use 4.1.8.11.3a :
$T_{a} = {\begin{matrix} 0.085 {(h_{n})}^{3 / 4} & for steel moment frames \\ 0.075 {(h_{n})}^{3 / 4} & for concrete moment frames \\ 0.1 N & for other frames \end{matrix}$
Clause (b): Use 4.1.8.11.3b : T_α = 0.025 h_n for braced frames
Clause (c): Use 4.1.8.11.3c : T_α = 0.050 (h_n)^3/4 for shear wall and other structures

Note that h_n is height of the building (in meters). In above equations, all options are implemented in the program except 0.1N. Instead, you are always allowed to defined your own value for T_α.

In addition, if required, the program calculates fundamental period from an Eigen analysis, and you are also provided a method to use this as well. The above equation is subjected to the following limits:

For moment resisting frames: T_α ≤ 1.5 * that determined in Clause (a)
For braced frames: T_α ≤ 2.0 * that determined in Clause (b)
For Shear Wall Structures: T_α ≤ 2.0 * that determined in Clause (c)

Note that these upper limits specified above may not be checked for deflection/drift calculations.

Base Shear Adjustment Factor Due to Higher Modes, Mv

This factor is read from Table 4.1.8.11, based on type of lateral resisting systems, Sa(0.2), Sa(2.0) and calculated value of Ta. You are required to choose lateral resisting system for each direction.

Importance Factor, I

It is given in Table 4.1.8.5

Load Directions

Four load cases are generated as follows:

Generated Load Cases for NBC of Canada 2005 Seismic

100%/30% orthogonal loading is implemented in the software as referenced in 4.1.8.8.

Generate Additional Load Cases for Analysis with Tension-Only Members

RAM Frame utilizes a nonlinear analysis algorithm to keep track of tension-only members during solution of the structural model under applied loads. Since the process has a nonlinear (iterative) nature, analysis results can not be simply superposed with other results as in load combination option in RAM Frame. Therefore, each lateral load case (wind or seismic) are solved separately.

Since the direction of the lateral loads become important in an iterative analysis, RAM Frame provides an option such that additional load cases can be created upon user request. When Generate Additional Load Cases for Analysis with Tension-Only Members in generating lateral load cases (wind and seismic load cases only) is invoked, additional load cases are created. For instance, there are 12 load cases generated for a regular IBC 2000 (ASCE 7-98) Wind load case. If this box is checked, the number of the load cases becomes 22. Additional load cases are created to account for directional effects of applied loads so that the most severe loading case is captured.

Conceptual example of additional load cases for tension-only members

NBCC-2015 Seismic

Setting

Description

Load Case

States the Label of the load case being defined.

Direction

Use the Direction box to indicate the direction of the force (X, Y, or both) by clicking on the corresponding box so that the box is marked. One load case will be generated for each direction at which the force acts.

Eccentricity

You may choose to include the effects of accidental torsion in the application of the seismic forces. The value of eccentricity used is specified in Loads - Masses. A default value of 5% is assumed by the program. See building code for more information.

Force Modification Factors

The following must be provided for both X-Dir and Y-Dir:

Setting	Description
Rd	Ductility related force modification factor, R_d, reflecting the capability of a structure to dissipate energy through inelastic behavior is required from the user for each direction. This factor is provided in Table 4.1.8.9.
Ro	Overstrength related force modification factor, R_o, accounting for the dependable portion of reserve strength in a structure is required from the user for each direction. This factor is provided in Table 4.1.8.9.

Base Shear Adjustment Factor Due to Higher Modes, Mv

This factor is read from Table 4.1.8.11, based on type of lateral resisting systems, Sa(0.2), Sa(2.0) and calculated value of Ta. You are required to choose lateral resisting system for each direction.

Structural Period

The fundamental period (Ta) is based on one of the following choices:

Clause (a): Use 4.1.8.11.3a :
$T_{a} = {\begin{matrix} 0.085 {(h_{n})}^{3 / 4} & for steel moment frames \\ 0.075 {(h_{n})}^{3 / 4} & for concrete moment frames \\ 0.1 N & for other frames \end{matrix}$
Clause (b): Use 4.1.8.11.3b : T_α = 0.025 h_n for braced frames
Clause (c): Use 4.1.8.11.3c : T_α = 0.050 (h_n)^3/4 for shear wall and other structures

Note that h_n is height of the building (in meters). In above equations, all options are implemented in the program except 0.1N. Instead, you are always allowed to defined your own value for T_α.

In addition, if required, the program calculates fundamental period from an Eigen analysis, and you are also provided a method to use this as well. The above equation is subjected to the following limits:

For moment resisting frames: T_α ≤ 1.5 * that determined in Clause (a)
For braced frames: T_α ≤ 2.0 * that determined in Clause (b)
For Shear Wall Structures: T_α ≤ 2.0 * that determined in Clause (c)

Note that these upper limits specified above may not be checked for deflection/drift calculations.

Importance Factor, I

It is given in Table 4.1.8.5

Consider Orthogonal Effects (100%/30%)

Four load cases are generated as follows:

Generated Load Cases for NBC of Canada 2005 Seismic

100%/30% orthogonal loading is implemented in the software as referenced in 4.1.8.8.

Generate Additional Load Cases for Analysis with Tension-Only Members

RAM Frame utilizes a nonlinear analysis algorithm to keep track of tension-only members during solution of the structural model under applied loads. Since the process has a nonlinear (iterative) nature, analysis results can not be simply superposed with other results as in load combination option in RAM Frame. Therefore, each lateral load case (wind or seismic) are solved separately.

Since the direction of the lateral loads become important in an iterative analysis, RAM Frame provides an option such that additional load cases can be created upon user request. When Generate Additional Load Cases for Analysis with Tension-Only Members in generating lateral load cases (wind and seismic load cases only) is invoked, additional load cases are created. For instance, there are 12 load cases generated for a regular IBC 2000 (ASCE 7-98) Wind load case. If this box is checked, the number of the load cases becomes 22. Additional load cases are created to account for directional effects of applied loads so that the most severe loading case is captured.

Conceptual example of additional load cases for tension-only members

China GB50011-2001

Setting

Description

Load Case

States the Label of the load case being defined.

Direction

Use the Direction box to indicate the direction of the force (X, Y, or both) by clicking on the corresponding box so that the box is marked. One load case will be generated for each direction at which the force acts.

Eccentricity

You may choose to include the effects of accidental torsion in the application of the seismic forces. The value of eccentricity used is specified in Loads - Masses. A default value of 5% is assumed by the program. See building code for more information.

Structure Period

Structure periods can be automatically calculated by the program for both X and Y direction (note that the program considers period that is based on the Eigen mode (i.e., mode shape) with highest building mass participation). Or, the user can enter structure period for X and Y direction separately. Note that if the 1st option is chosen (Use Calculated T), then the period multiplier is directly applied to calculated period (by default, it is 1.0).

Additional Seismic Action Factor

Additional seismic action factor, δ_n, is defined at the top of the building and thus, an additional force, ΔFn, is applied at the top:

ΔF_n = δ_n F_EK

where

F_EK

=

the building base shear

The following options are provided to calculate δn:

it is not considered (i.e., ΔF_n =0)
δn is provided by the engineer
it is directly read from the Table 5.2.1 of GB50011-2001.

Earthquake Group

The following earthquake groups are available: 1, 2 and 3.

Earthquake Type

The following earthquake types are available : Frequent and Rare

Soil Site Class

The following soil site class are available: I, II, III, and IV

Fortification Intensity

The following fortification intensities are available: 6, 7, 7(0.15g), 8, 8(0.30g) and 9. Values with parenthesis are used for design basic acceleration of ground motion with 0.15g and 0.30g.

Base Shear Scale Factors

These factors are directly applied to calculated building seismic base shears in both X and Y directions.

Generate Additional Load Cases for Analysis with Tension-Only Members

RAM Frame utilizes a nonlinear analysis algorithm to keep track of tension-only members during solution of the structural model under applied loads. Since the process has a nonlinear (iterative) nature, analysis results can not be simply superposed with other results as in load combination option in RAM Frame. Therefore, each lateral load case (wind or seismic) are solved separately.

Since the direction of the lateral loads become important in an iterative analysis, RAM Frame provides an option such that additional load cases can be created upon user request. When Generate Additional Load Cases for Analysis with Tension-Only Members in generating lateral load cases (wind and seismic load cases only) is invoked, additional load cases are created. For instance, there are 12 load cases generated for a regular IBC 2000 (ASCE 7-98) Wind load case. If this box is checked, the number of the load cases becomes 22. Additional load cases are created to account for directional effects of applied loads so that the most severe loading case is captured.

Conceptual example of additional load cases for tension-only members

AS 1170.4-2007

Setting

Description

Load Case

States the Label of the load case being defined.

Direction

Use the Direction box to indicate the direction of the force (X, Y, or both) by clicking on the corresponding box so that the box is marked. One load case will be generated for each direction at which the force acts.

Eccentricity

You may choose to include the effects of accidental torsion in the application of the seismic forces. The value of eccentricity used is specified in Loads - Masses. A default value of 5% is assumed by the program. See building code for more information.

Structure Period

Three options are provided to user for natural period of structure in X- and Y-directions:

Either it is directly calculated by the program
Or it is directly provided by user

Or it is calculated according to Eq. 6.2(7):

T₁ = 1.25k_th_n^0.75

6.2(7)

where k_t is defined as follows:

Frame Type	k_t
Moment-resisting steel frames	0.11
Moment-resisting concrete frames	0.075
Eccentrically braced steel frames	0.06
All other structures	0.05

The base shear obtained using either calculated by the program or user entered shall not be less than 80% of the value obtained with T₁ according to above equation. Thus, the user needs to enter k_t for each direction for fulfilling this requirement. This check is enforced in the program.

Building Seismic Properties group

Type values for both X and Y directions.

Setting	Description
Structural Ductility Factor (mu)	µ; Refer to Section 6.5 of the building code
Structural Performance Factor (Sp)	Refer to Section 6.5 of the building code

Site Hazard Factors

Setting	Description
Probability Factor (kp)	Refer to Section 3, Table 3.1 of the building code
Hazard Factor (Z)	Refer to Section 3, Table 3.2 of the building code

Site Sub-soil Class

Select one of the five different site sub-soil class: Ae. Be, Ce, De, or Ee

Generate Additional Load Cases for Analysis with Tension-Only Members

RAM Frame utilizes a nonlinear analysis algorithm to keep track of tension-only members during solution of the structural model under applied loads. Since the process has a nonlinear (iterative) nature, analysis results can not be simply superposed with other results as in load combination option in RAM Frame. Therefore, each lateral load case (wind or seismic) are solved separately.

Since the direction of the lateral loads become important in an iterative analysis, RAM Frame provides an option such that additional load cases can be created upon user request. When Generate Additional Load Cases for Analysis with Tension-Only Members in generating lateral load cases (wind and seismic load cases only) is invoked, additional load cases are created. For instance, there are 12 load cases generated for a regular IBC 2000 (ASCE 7-98) Wind load case. If this box is checked, the number of the load cases becomes 22. Additional load cases are created to account for directional effects of applied loads so that the most severe loading case is captured.

Conceptual example of additional load cases for tension-only members

Orthogonal Effects (100/30)

Orthogonal load cases can be created based on the 100%/30% requirement of some building codes: loads are applied 100% in one direction and 30% in the orthogonal direction at the same time. This is only implemented for US seismic load cases. To invoke this feature, select the Consider Orthogonal Effects (100/30) option when generating seismic load cases. Note that invoking this option substantially increases the number of load cases created. For instance, a total of 36 different load cases (40 if Generate Additional Load Cases for Analysis with Tension-Only Members is also checked) are created for IBC 2000 seismic load case. The following figure shows an example of the generated load cases.

Generated load cases based on 100%/30% rule and additional cases for tension-only members

IS 1893 (Part1): 2002, 5th Rev. / 2016, 6th Rev.

Setting	Description
Load Case	States the Label of the load case being defined.
Direction	Use the Direction box to indicate the direction of the force (X, Y, or both) by clicking on the corresponding box so that the box is marked. One load case will be generated for each direction at which the force acts.
Eccentricity	You may choose to include the effects of accidental torsion in the application of the seismic forces. The value of eccentricity used is specified in Loads - Masses. A default value of 5% is assumed by the program. See building code for more information.
Structural Period	This is the period of the building which can be obtained through eigenvalue analysis or through the specified code equations. See building code for more information.
R	The response modification coefficient is defined by and specified in the appropriate code. See building code for more information.
Soil Site Type	Select the applicable soil description. Type I (Rocky or Hard Soil) Type II (Medium Soil) Type III (Soft Soil)
Seismic Zone Factor	Select the seismic intensity from the list.
Importance Factor	The Importance Factor is defined by and specified in the appropriate code. See the building code for more information.
Damping	(2002, 5th Rev only) Specify a damping ratio which is used to modify the the Sa/g values.
Orthogonal Effects (100/30)	Orthogonal load cases can be created based on the 100%/30% requirement of some building codes: loads are applied 100% in one direction and 30% in the orthogonal direction at the same time. This is only implemented for US seismic load cases. To invoke this feature, select the Consider Orthogonal Effects (100/30) option when generating seismic load cases. Note that invoking this option substantially increases the number of load cases created. For instance, a total of 36 different load cases (40 if Generate Additional Load Cases for Analysis with Tension-Only Members is also checked) are created for IBC 2000 seismic load case. The following figure shows an example of the generated load cases. Generated load cases based on 100%/30% rule and additional cases for tension-only members
Generate Additional Load Cases for Analysis with Tension-Only Members	RAM Frame utilizes a nonlinear analysis algorithm to keep track of tension-only members during solution of the structural model under applied loads. Since the process has a nonlinear (iterative) nature, analysis results can not be simply superposed with other results as in load combination option in RAM Frame. Therefore, each lateral load case (wind or seismic) are solved separately. Since the direction of the lateral loads become important in an iterative analysis, RAM Frame provides an option such that additional load cases can be created upon user request. When Generate Additional Load Cases for Analysis with Tension-Only Members in generating lateral load cases (wind and seismic load cases only) is invoked, additional load cases are created. For instance, there are 12 load cases generated for a regular IBC 2000 (ASCE 7-98) Wind load case. If this box is checked, the number of the load cases becomes 22. Additional load cases are created to account for directional effects of applied loads so that the most severe loading case is captured. Conceptual example of additional load cases for tension-only members

All Other Building Codes

Setting	Description
Load Case	States the Label of the load case being defined.
Load Case Provisions	The provisions for calculating seismic forces vary depending on whether the generated forces are to be used for the calculation of drift, member forces or foundation forces. Load cases can be defined for each provision, allowing for the simultaneous investigation of the three conditions. See building code for more information.
Direction	Use the Direction box to indicate the direction of the force (X, Y, or both) by clicking on the corresponding box so that the box is marked. One load case will be generated for each direction at which the force acts.
Eccentricity	You may choose to include the effects of accidental torsion in the application of the seismic forces. The value of eccentricity used is specified in Loads - Masses. A default value of 5% is assumed by the program. See building code for more information.
Structural Period	This is the period of the building which can be obtained through eigenvalue analysis or through the specified code equations. See building code for more information.
R	The response modification coefficient is defined by and specified in the appropriate code. See building code for more information.
Soil	The Soil Profile Type is defined by and specified in the appropriate code. See the building code for more information.
Av	The seismic coefficient representing the effective peak velocity. See the building code for more information.
Aa	The seismic coefficient representing the effective peak acceleration. See the building code for more information.
Generate Additional Load Cases for Analysis with Tension-Only Members	RAM Frame utilizes a nonlinear analysis algorithm to keep track of tension-only members during solution of the structural model under applied loads. Since the process has a nonlinear (iterative) nature, analysis results can not be simply superposed with other results as in load combination option in RAM Frame. Therefore, each lateral load case (wind or seismic) are solved separately. Since the direction of the lateral loads become important in an iterative analysis, RAM Frame provides an option such that additional load cases can be created upon user request. When Generate Additional Load Cases for Analysis with Tension-Only Members in generating lateral load cases (wind and seismic load cases only) is invoked, additional load cases are created. For instance, there are 12 load cases generated for a regular IBC 2000 (ASCE 7-98) Wind load case. If this box is checked, the number of the load cases becomes 22. Additional load cases are created to account for directional effects of applied loads so that the most severe loading case is captured. Conceptual example of additional load cases for tension-only members
Orthogonal Effects (100/30)	Orthogonal load cases can be created based on the 100%/30% requirement of some building codes: loads are applied 100% in one direction and 30% in the orthogonal direction at the same time. This is only implemented for US seismic load cases. To invoke this feature, select the Consider Orthogonal Effects (100/30) option when generating seismic load cases. Note that invoking this option substantially increases the number of load cases created. For instance, a total of 36 different load cases (40 if Generate Additional Load Cases for Analysis with Tension-Only Members is also checked) are created for IBC 2000 seismic load case. The following figure shows an example of the generated load cases. Generated load cases based on 100%/30% rule and additional cases for tension-only members

RAM Structural System Help

Seismic Load Cases

User Defined Story Forces

Building Code Defined Story Forces

Conceptual example of additional load cases for tension-only members

Generated load cases based on 100%/30% rule and additional cases for tension-only members

Conceptual example of additional load cases for tension-only members

Generated load cases based on 100%/30% rule and additional cases for tension-only members

Conceptual example of additional load cases for tension-only members

Generated load cases based on 100%/30% rule and additional cases for tension-only members

Conceptual example of additional load cases for tension-only members

Generated load cases based on 100%/30% rule and additional cases for tension-only members

Conceptual example of additional load cases for tension-only members

Conceptual example of additional load cases for tension-only members

Generated Load Cases for NBC of Canada 2005 Seismic

Conceptual example of additional load cases for tension-only members

Generated Load Cases for NBC of Canada 2005 Seismic

Conceptual example of additional load cases for tension-only members

Conceptual example of additional load cases for tension-only members

Conceptual example of additional load cases for tension-only members

Generated load cases based on 100%/30% rule and additional cases for tension-only members

Generated load cases based on 100%/30% rule and additional cases for tension-only members

Conceptual example of additional load cases for tension-only members

Conceptual example of additional load cases for tension-only members

Generated load cases based on 100%/30% rule and additional cases for tension-only members