~DEFSPEC
~DEFSPEC, Lab, VAL1, VAL2, VAL3, VAL4, VAL5, VAL6, ..., VAL21
Defines the design spectrum according to the active seismic code
SEISMIC: Spectral Analysis
The spectrum may be calculated using the seismic code definition or may be defined as a user table.
Spectrum calculated from the seismic code:
~DEFSPEC, Lab, VAL1, VAL2, VAL3, VAL4, VAL5, VAL6, VAL7, VAL8
Lab
Property to define. The values for Lab depend on the selected code:
- Eurocode No. 8:
|
ALL |
Definition of all the values. |
|
AG |
Design seismic acceleration. |
|
SCLASS |
Subsoil class. |
|
SPTYPE |
Spectrum type that will be used for the analysis. |
|
QH |
Horizontal behavior factor. (Default value = 1.0) |
|
QV |
Vertical behavior factor. (Default value = 1.0) |
|
DMPRAT |
Damping factor in %. (Default value = 5.0) |
- Spanish code NCSE-94:
|
ALL |
Definition of all the values. |
|
AB |
Basic acceleration (× g). |
|
SCLASS |
Subsoil class. |
|
SPTYPE |
Spectrum type that will be used for the analysis. |
|
TU |
Life time of the project in years. (Default value = 50.0) |
|
K |
Contribution factor. (Default value = 1.0) |
|
OMEGA |
Damping factor in %. (Default value = 5.0) |
|
MU |
Ductility. (Default value = 1.0) |
- Spanish code NCSE-02:
|
ALL |
Definition of all the values. |
|
AB |
Basic acceleration (× g). |
|
SCLASS |
Soil class. |
|
SPTYPE |
Spectrum type that will be used for the analysis. |
|
RO |
Risk coefficient. (Default value = 1.0) |
|
K |
Contribution factor. (Default value = 1.0) |
|
OMEGA |
Damping factor in %. (Default value = 5.0) |
|
MU |
Ductility. (Default value = 1.0) |
- Chinese code GB50011:
|
ALL |
Definition of all the values. |
|
AB |
Basic acceleration (× g). |
|
SPTYPE |
Spectrum type "FREQ" or "RARE". (Default value = "FREQ"). |
|
GROUND |
Terrain type "I", "II","III","IV". |
|
GROUP |
Design group 1, 2 or 3. (Default value = 1) |
|
DMPRAT |
Damping coefficient. (Default value = 0.05) |
|
VFACT |
Factor that multiplies the horizontal spectrum to obtain the vertical spectrum (Default value = 0.70) |
- Italian code IT3274:
|
ALL |
Definition of all the values. |
|
AG |
Design seismic acceleration. |
|
SCLASS |
Subsoil class. |
|
SPTYPE |
Spectrum type that will be used for the analysis. |
|
QH |
Horizontal behavior factor. (Default value = 1.0) |
|
QV |
Vertical behavior factor. (Default value = 1.0) |
|
DMPRAT |
Damping factor in %. (Default value = 5.0) |
- AASHTO LRFD Bridge Design Specifications:
|
ALL |
Definition of all the values. |
|
A |
Ground acceleration coefficient. |
|
SPROFILE |
Soil Profile Type "I", "II", "III", "IV". |
|
R |
Response modification factor. |
|
DMPRAT |
Damping factor in %. (Default value = 2.0) |
|
VFACT |
Factor that multiplies the horizontal spectrum to obtain the vertical spectrum (Default value = 1.00) |
- Greek code EAK 2000:
|
ALL |
Definition of all the values. |
|
SZONE |
Seismic risk zone. |
|
SCLASS |
Soil type. |
|
SPTYPE |
Spectrum type that will be used for the analysis. |
|
QH |
Horizontal behavior factor. (Default value = 1.0) |
|
DMPRAT |
Damping factor in %. (Default value = 5.0) |
|
GAMMA1 |
Importance factor of the structure. (Default value = 1.3) |
|
THETA |
Influence factor of the foundation. (Default value = 0.9) |
- CALTRANS Seismic Design Criteria:
|
ALL |
Definition of all the values. |
|
A |
Peak rock acceleration coefficient. |
|
SPROFILE |
Soil profile type and earthquake magnitude. |
|
MODIF |
Modification to the standard ARS curves. |
|
DMPRAT |
Damping factor in %. (Default value = 5.0) |
|
VFACT |
Factor that multiplies the horizontal spectrum to obtain the vertical spectrum (Default value = 1.00) |
- 1997 Uniform Building Code:
|
ALL |
Definition of all the values. |
|
ZONE |
Seismic risk zone. |
|
SPROFILE |
Soil profile. |
|
SPTYPE |
Spectrum type that will be used for the analysis. |
|
SOURCE |
Seismic source type. |
|
DIST |
Closest distance to known seismic source in Km. (Default value = 2.0 Km) |
|
DMPRAT |
Damping factor in %. (Default value = 5.0) |
|
VFACT |
Factor that multiplies the horizontal spectrum to obtain the vertical spectrum (Default value = 2/3). |
- French code PS92:
|
ALL |
Definition of all the values. |
|
AN |
Nominal acceleration. |
|
SCLASS |
Soil class. |
|
SPTYPE |
Spectrum type that will be used for the analysis. |
|
TAU |
Topographic amplification factor. (Default value = 1.0) |
|
DMPRAT |
Damping factor in %. (Default value = 5.0) |
- Indian Standard IS1893:
|
ALL |
Definition of all the values. |
|
SZONE |
Seismic zone. |
|
STYPE |
Soil type. |
|
SPTYPE |
Spectrum type that will be used for the analysis. |
|
I |
Importance factor. (Default value = 1.0) |
|
R |
Response reduction factor. (Default value = 1.0) |
|
DMPRAT |
Damping factor in %. (Default value = 5.0) |
VAL1
Value to assign to the datum according to the active seismic code.
Eurocode No. 8:
|
Lab |
VAL1 |
Description |
|
AG |
AG |
Design seismic acceleration. (Part 1-1, Art. 4.2.2) |
|
SCLASS |
A |
Subsoil class A. (Part 1-1, Art. 4.2.2). |
|
|
B |
Subsoil class B. |
|
|
C |
Subsoil class C. |
|
SPTYPE |
LINEAR |
Spectrum type that will be used for the analysis (Part 1-1, Art. 4.2.2 and 4.2.4). |
|
|
ELASTIC |
|
|
QH |
QH |
Horizontal behaviour factor. (Part 1-3, Sections 2 and 3). |
|
QV |
QV |
Vertical behaviour factor. (Part 1-3, Sections 2 and 3). |
|
DMPRAT |
DMPRAT |
Damping factor in z %. (Part 1-1, Art. 4.2.2). |
Spanish code NCSE-94:
|
Lab |
VAL1 |
Description |
|
AB |
AB |
Basic acceleration [ab/g]. (Art. 2.1, Fig. 2.1 and Annex 1). |
|
SCLASS |
I |
Subsoil class I. (Art. 2.3.1). |
|
|
II |
Subsoil class II. (Art. 2.3.1). |
|
 |
III |
Subsoil class III. (Art. 2.3.1). |
|
SPTYPE |
ELASTIC |
Spectrum type that will be used for the analysis. |
|
|
DESIGN |
|
|
TU |
TU |
Life time of the project in years. (Art. 2.2). |
|
K |
K |
Contribution factor. (Art. 2.3 and Annex 1). |
|
OMEGA |
OMEGA |
Structure type identified through the value of the OMEGA coefficient. Damping factor in %. (Art. 3.7.3.1). |
|
MU |
MU |
Ductility. (Art. 3.7.3.1, Tab. 3.1). |
Spanish code NCSE-02:
|
Lab |
VAL1 |
Description |
|
AB |
AB |
Basic acceleration [ab/g]. (Art. 2.1, Fig. 2.1 and Annex 1). |
|
SCLASS |
I |
Subsoil class I (Art. 2.3.1). |
|
|
II |
Subsoil class II (Art. 2.3.1). |
|
 |
III |
Subsoil class III (Art. 2.3.1). |
|
|
IV |
Subsoil class IV (Art. 2.3.1). |
|
SPTYPE |
ELASTIC |
Spectrum type that will be used for the analysis. |
|
|
DESIGN |
|
|
RO |
RO |
Risk factor. |
|
K |
K |
Contribution factor. (Art. 2.3 and Annex 1). |
|
OMEGA |
OMEGA |
Structure type identified through the value of the OMEGA coefficient. Damping factor in % (Art. 3.7.3.1). |
|
MU |
MU |
Ductility. (Art. 3.7.3.1, Tab. 3.1). |
Chinese code GB50011:
|
Lab |
VAL1 |
Description |
|
AB |
AB |
Basic acceleration [ab/g]. (Art. 2.1, Fig. 2.1 and Annex 1). |
|
STYPE |
FREQ |
Frequent seismic type |
|
|
RARE |
Rare seismic type |
|
GROUND |
I |
Soil type |
|
|
II |
Soil type |
|
|
III |
Soil type |
|
|
IV |
Soil type |
|
GROUP |
1 |
Design Group |
|
|
2 |
Design Group |
|
|
3 |
Design Group |
|
DMPRAT |
DMPRAT |
Damping coefficient. |
|
VFACT |
VFACT |
Factor that multiplies the horizontal spectrum to obtain the vertical spectrum. |
Italian code IT3274:
|
Lab |
VAL1 |
Description |
|
AG |
AG |
Design seismic acceleration. (Art. 3.2.1) |
|
SCLASS |
A |
Subsoil class A (Art. 3.2.3). |
|
|
B |
Subsoil class B. |
|
|
C |
Subsoil class C. |
|
|
D |
Subsoil class D. |
|
|
E |
Subsoil class E. |
|
SPTYPE |
ELASTIC |
Spectrum type that will be used for the analysis (Art. 3.2.3). |
|
|
DESIGN |
|
|
QH |
QH |
Horizontal behaviour factor. (Art. 3.2.5). |
|
QV |
QV |
Vertical behaviour factor. (Art. 3.2.5). |
|
DMPRAT |
DMPRAT |
Damping factor z in %. (Art. 3.2.3). |
AASHTO LRFD Bridge Design Specifications:
|
Lab |
VAL1 |
Description |
|
A |
A |
Ground acceleration coefficient. (Art. 3.10.2). |
|
SPROFILE |
I |
Soil Profile Type (Art. 3.10.5.2). |
|
|
II |
Soil Profile Type (Art. 3.10.5.3). |
|
|
III |
Soil Profile Type (Art. 3.10.5.4). |
|
|
IV |
Soil Profile Type (Art. 3.10.5.5). |
|
R |
R |
Response modification factor (Art.3.10.7). |
|
DMPRAT |
DMPRAT |
Damping factor in %. (Art. 4.7.1.4). |
|
VFACT |
VFACT |
Factor that multiplies the horizontal spectrum to obtain the vertical spectrum. |
Greek code EAK2000:
|
Lab |
VAL1 |
Description |
|
SZONE |
I |
Seismic risk zone. (Art. 2.3.3) |
|
|
II |
|
|
|
III |
|
|
|
IV |
|
|
SCLASS |
A |
Soil type A. (Art. 2.3.6). |
|
|
B |
Soil type B. |
|
|
G |
Soil type G. |
|
|
D |
Soil type D. |
|
SPTYPE |
ELASTIC |
Spectrum type that will be used for the analysis (Art. 2.2.2). |
|
|
DESIGN |
|
|
Q |
Q |
Horizontal behaviour factor. (Art. 2.3.5). |
|
DMPRAT |
DMPRAT |
Damping factor z in %. (Art. 2.3.1). |
|
GAMMA1 |
GAMMA1 |
Importance factor of the structure in %. (Art. 2.3.4). |
|
THETA |
THETA |
Influence factor of the foundation. (Art. 2.2.2.6) |
CALTRANS Seismic Design Criteria:
|
Lab |
VAL1 |
Description |
|
A |
A |
Ground acceleration coefficient. |
|
SPROFILE |
B1 |
Soil profile type B (Table B.1) and earthquake magnitude of 6.5 ±0.25. |
|
|
B2 |
Soil profile type B (Table B.1) and earthquake magnitude of 7.25 ±0.25. |
|
|
B3 |
Soil profile type B (Table B.1) and earthquake magnitude of 8.5 ±0.25. |
|
|
C1 |
Soil profile type C (Table B.1) and earthquake magnitude of 6.5 ±0.25. |
|
|
C2 |
Soil profile type C (Table B.1) and earthquake magnitude of 7.25 ±0.25. |
|
|
C3 |
Soil profile type C (Table B.1) and earthquake magnitude of 8.5 ±0.25. |
|
|
D1 |
Soil profile type D (Table B.1) and earthquake magnitude of 6.5 ±0.25. |
|
|
D2 |
Soil profile type D (Table B.1) and earthquake magnitude of 7.25 ±0.25. |
|
|
D3 |
Soil profile type D (Table B.1) and earthquake magnitude of 8.5 ±0.25. |
|
|
E1 |
Soil profile type E (Table B.1) and earthquake magnitude of 6.5 ±0.25. |
|
|
E2 |
Soil profile type E (Table B.1) and earthquake magnitude of 7.25 ±0.25. |
|
|
E3 |
Soil profile type E (Table B.1) and earthquake magnitude of 8.5 ±0.25. |
|
MODIF |
0 |
No modification to the standard ARS curve (Art. 6.1.2.1). |
|
|
1 |
Structures within 10 miles (15 km) of an active fault (Art. 6.1.2.1) |
|
|
2 |
Structures with a fundamental period of vibration T ³ 1.5s on deep soil sites (Art. 6.1.2.1) |
|
DMPRAT |
DMPRAT |
Damping factor c in %. (Art. 2.1.5). |
|
VFACT |
VFACT |
Factor that multiplies the horizontal spectrum to obtain the vertical spectrum. |
1997 Uniform Building Code:
|
Lab |
VAL1 |
Description |
|
ZONE |
1 |
Seismic risk zone. (Art. 1629.4.1) |
|
|
2A |
|
|
|
2B |
|
|
|
3 |
|
|
|
4 |
|
|
SPROFILE |
A |
Soil type SA. (Art. 1629.3.1). |
|
|
B |
Soil type SB. |
|
|
C |
Soil type SC. |
|
|
D |
Soil type SD. |
|
|
E |
Soil type SE. |
|
SPTYPE |
DESIGN |
Spectrum type that will be used for the analysis refers to the design-basis earthquake. |
|
|
MAXIMUM |
Spectrum type that will be used for the analysis refers to the maximum capable earthquake. |
|
SOURCE |
A |
Seismic source type. (Art. 1629.4.2). |
|
|
B |
|
|
|
C |
|
|
DIST |
DIST |
Closest distance to known seismic source in km. (Default value = 2 km). (Art. 1629.4.2). |
|
DMPRAT |
DMPRAT |
Damping factor in %. |
|
VFACT |
VFACT |
Factor that multiplies the horizontal spectrum to obtain the vertical spectrum (Default value = 2/3). (Art. 1631.2). |
French code PS92:
|
Lab |
VAL1 |
Description |
|
AN |
AN |
Nominal acceleration. (Art. 3.3) |
|
SCLASS |
S0 |
Soil class S0. (Art. 5.22). |
|
|
S1 |
Soil class S1. |
|
|
S2 |
Soil class S2. |
|
|
S3 |
Soil class S3. |
|
SPTYPE |
ELASTIC |
Spectrum type that will be used for the analysis. |
|
|
DESIGN |
|
|
TAU |
TAU |
Topographic amplification factor. (Art. 5.24). |
|
DMPRAT |
DMPRAT |
Damping factor z in %. (Art. 5.234). |
Indian Standard IS1893:
|
Lab |
VAL1 |
Description |
|
SZONE |
II |
Seismic zone. (Art. 6.4.2) |
|
|
III |
|
|
|
IV |
|
|
|
V |
|
|
STYPE |
I |
Soil type I (rock, or hard soil). (Art. 6.4.2). |
|
|
II |
Soil type II (medium soil). |
|
|
III |
Soil type III (soft soil). |
|
SPTYPE |
DESIGN |
Spectrum type that will be used for the analysis (Art. 6.4.2): Design basis earthquake or Maximum considered earthquake. |
|
|
MAXIMUM |
|
|
I |
I |
Importance factor. (Art. 6.4.2). |
|
R |
R |
Response reduction factor (Art. 6.4.2). |
|
DMPRAT |
DMPRAT |
Damping factor in %. (Art. 6.4.2 and 6.4.5). |
Spectrum defined as a user table:
~DEFSPEC, Lab, VAL1, VAL2, VAL3, VAL4, VAL5, VAL6, ..., VAL21
Lab
|
PERIH |
Periods for the horizontal spectrum (from VAL1 to VAL20). Must be entered in ascending order and before the acceleration values. DAMP is ignored. |
|
PERIV |
Periods for the vertical spectrum (from VAL1 to VAL20). Must be entered in ascending order and before the acceleration values. |
|
SAH |
Accelerations for the horizontal spectrum (from VAL2 to VAL21). Must be entered in the same order as the previously defined periods. VAL1 is the damping ratio for the spectrum currently being defined. Up to four diferent horizontal spectra can be defined, each for a different damping. |
|
SAV |
Accelerations for the vertical spectrum (from VAL2 to VAL21). Must be entered in the same order as the previously defined periods. VAL1 is the damping ratio for the spectrum currently being defined. Up to four diferent vertical spectra can be defined, each for a different damping. |
The values for the periods or accelerations can be defined in consecutive commands. For example:
~DEFSPEC, PERIH, 1.0, 2.0, 3.0
~DEFSPEC, PERIH, 4.0, 5.0
~DEFSPEC, SAH, 0.05, 0.10, 0.35, 0.35, 0.20
~DEFSPEC, SAH, 0.05, 0.15
~DEFSPEC, SAH, 0.03, 0.05, 0.25, 0.25, 0.10, 0.10
An empty PERIH command (all values null) will erase the defined horizontal spectra.
An empty PERIV command (all values null) will erase the defined vertical spectra.
Note
- It is possible to introduce, in only one step, all the necessary data to calculate the spectrum, according to the active seismic code, as shown below:
Eurocode No. 8: ~DEFSPEC, ALL, AG, SCLASS, SPTYPE, QH, QV, DMPRAT
Spanish code NCSE-94: ~DEFSPEC, ALL, AB, SCALSS, SPTYPE, TU, K, OMEGA, MU
Spanish code NCSE-02: ~DEFSPEC, ALL, AB, SCALSS, SPTYPE, RO, K, OMEGA, MU
Chinese code GB50011: ~DEFSPEC, ALL, AB, STYPE, GROUND, GROUP, DMPRAT, VFACT
Italian code IT3274: ~DEFSPEC, ALL, AG, SCLASS, SPTYPE, QH, QV, DMPRAT
AASHTO LRFD Bridge Design Specifications: ~DEFSPEC, ALL, A, SPROFILE, R, VFACT.
Greek code EAK 2000: ~DEFSPEC, ALL, SZONE, SCLASS, SPTYPE, Q, DMPRAT, GAMMA1, THETA
CALTRANS Seismic Design Criteria: ~DEFSPEC, ALL, A, SPROFILE, MODIF, DMPRAT, VFACT
1997 Uniform Building code: ~DEFSPEC, ALL, ZONE, SPROFILE, SPTYPE, SOURCE, DIST, VFACT
French code PS92: ~DEFSPEC, ALL, AN, SCLASS, SPTYPE, TAU, DMPRAT
Indian Standard IS1893: ~DEFSPEC, ALL, SZONE, STYPE, SPTYPE, I, R, DMPRAT
Menu Paths
Main Menu > CIVIL Seismic Design > Define Spectra> By Code
Main Menu > CIVIL Seismic Design > Define Spectra> Horiz. Period Table
Main Menu > CIVIL Seismic Design > Define Spectra> Horiz. Spectr. Values
Main Menu > CIVIL Seismic Design > Define Spectra> Delete Horiz. Spectra
Main Menu > CIVIL Seismic Design > Define Spectra> Vert. Period Table
Main Menu > CIVIL Seismic Design > Define Spectra> Vert. Spectr. Values
Main Menu > CIVIL Seismic Design > Define Spectra> Delete Vert. Spectra
¾¾¾¾¾¾¨¾¾¾¾¾¾