STRUCTURAL MODEL VERIFICATION REPORT

Automated Structural Model Verification Tool for ETABS | SQVE-MV-ET-01 | Ver 1.0


Model File : D:\1-Tech\Software demo\1-Tall building\1-Tall building.EDB

Report Generated : 28-Mar-2026 20:09:51



1. INTRODUCTION

Model verification is a key step in structural quality assurance.


The Structural Model Verification Tool performs automated checks on selected parameters

of the ETABS model to assist engineers in reviewing model consistency and identifying

potential issues at an early stage.


This report presents the results of Phase-1 verification checks.

Additional automated checks will be incorporated in future versions of the tool

to further enhance the reliability of structural model review.



2. MASS SOURCE VERIFICATION

ℹ Note:

The following mass source multipliers correspond to different load patterns defined in the model.

The user should verify that appropriate scale factors are assigned,

and that no relevant load pattern is omitted from the mass source definition.


Mass Source Multipliers for different Load Patterns :

Dead : 1.00

Live : 0.50



ℹ Note:

For ready reference, the total dead load, live load, and reduced live load

considered in the structure are presented below.

These values help in verifying the magnitude of gravity loads

contributing to seismic mass.



Total Dead Load : 293340.69 kN

Total Live Load : 122880.00 kN

Reduced Live Load : 61440.00 kN


Total Gravity Load Used for Mass Calculation : 354780.69 kN


ℹ Note:

The structural mass calculated from applied gravity loads is compared

with the mass extracted from the ETABS joint mass table.

This comparison helps identify inconsistencies in mass modeling

or load application.


Calculated Structural Mass (from loads) : 36165208.23 kg

ETABS Mass Source (from Joint Mass Table) : 36177674.30 kg


ℹ Note:

Following shows the percentage difference between mass calculated from applied loads

and that obtained from joint masses.


Mass Difference : 0.03 %



✔ Result : PASS

Mass source definition appears consistent with applied loads in one of the directions.





3. MASS SOURCE DIRECTION CHECK

ℹ Note:

As per structural dynamics principles, seismic mass should be considered in all three translational directions (UX, UY, and UZ).

The following values show the total mass in each direction for ready reference and user verification.


Total UX Mass (kg) : 36177674.30

Total UY Mass (kg) : 36177674.30

Total UZ Mass (kg) : 0.00


⚠ WARNING : Vertical mass is absent.

➜ Recommendation : If vertical earthquake effects

are required to be considered as per the IS code provisions,

please enable vertical mass in the ETABS Mass Source definition.




4. STORY MASS CHECK

ℹ Note:

The following values represent story-wise seismic mass, taken as the maximum of mass values in UX, UY, and UZ directions.

Since mass is defined generally in three directions (UX, UY, and UZ), the maximum value among these is reported for each story.

The user should verify that the mass distribution is reasonable

and consistent across similar floors.


Story30 : 1045097.30 kg

Story29 : 1205922.40 kg

Story28 : 1205922.40 kg

Story27 : 1205922.40 kg

Story26 : 1205922.40 kg

Story25 : 1205922.40 kg

Story24 : 1205922.40 kg

Story23 : 1205922.40 kg

Story22 : 1205922.40 kg

Story21 : 1205922.40 kg

Story20 : 1205922.40 kg

Story19 : 1205922.40 kg

Story18 : 1205922.40 kg

Story17 : 1205922.40 kg

Story16 : 1205922.40 kg

Story15 : 1205922.40 kg

Story14 : 1205922.40 kg

Story13 : 1205922.40 kg

Story12 : 1205922.40 kg

Story11 : 1205922.40 kg

Story10 : 1205922.40 kg

Story9 : 1205922.40 kg

Story8 : 1205922.40 kg

Story7 : 1205922.40 kg

Story6 : 1205922.40 kg

Story5 : 1205922.40 kg

Story4 : 1205922.40 kg

Story3 : 1205922.40 kg

Story2 : 1205922.40 kg

Story1 : 1205922.40 kg

Base : 160827.40 kg




5. ADJACENT STORY MASS DIFFERENCE CHECK

ℹ Note:

For ready reference of the user, percentage difference in mass is also calculated for adjacent stories.

This provides an immediate indication of any inconsistencies in mass distribution.

Large variations may indicate modelling inconsistencies such as

missing loads, incorrect load assignment, or irregular geometry.


This will also help in identifying mass irregularities as per IS code provisions.


Base <-> Story1 : 86.66 %

Story1 <-> Story2 : 0.00 %

Story2 <-> Story3 : 0.00 %

Story3 <-> Story4 : 0.00 %

Story4 <-> Story5 : 0.00 %

Story5 <-> Story6 : 0.00 %

Story6 <-> Story7 : 0.00 %

Story7 <-> Story8 : 0.00 %

Story8 <-> Story9 : 0.00 %

Story9 <-> Story10 : 0.00 %

Story10 <-> Story11 : 0.00 %

Story11 <-> Story12 : 0.00 %

Story12 <-> Story13 : 0.00 %

Story13 <-> Story14 : 0.00 %

Story14 <-> Story15 : 0.00 %

Story15 <-> Story16 : 0.00 %

Story16 <-> Story17 : 0.00 %

Story17 <-> Story18 : 0.00 %

Story18 <-> Story19 : 0.00 %

Story19 <-> Story20 : 0.00 %

Story20 <-> Story21 : 0.00 %

Story21 <-> Story22 : 0.00 %

Story22 <-> Story23 : 0.00 %

Story23 <-> Story24 : 0.00 %

Story24 <-> Story25 : 0.00 %

Story25 <-> Story26 : 0.00 %

Story26 <-> Story27 : 0.00 %

Story27 <-> Story28 : 0.00 %

Story28 <-> Story29 : 0.00 %

Story29 <-> Story30 : 13.34 %



6. SEISMIC LOAD PATTERNS | IS 1893 (PART 1)- 2016

ℹ Note:

The following seismic load patterns are defined in the model

and are listed below for user reference.


In the subsequent sections, the total applied seismic load in the model

will be cross-checked for verification.


Detected 'Seismic' Load Pattern : EQX

Detected 'Seismic' Load Pattern : EQy

Detected 'Seismic' Load Pattern : RSX

Detected 'Seismic' Load Pattern : RSY



7. MAXIMUM BASE SHEAR

ℹ Note:

The following values represent the maximum base shear in X, Y, and Z directions,

extracted from all seismic load cases in the model.


These are envelope values and do not correspond to any single load case,

but represent the maximum response observed in each direction.


Vx(max) : 9432.46 kN

Vy(max) : 8476.88 kN

Vz(max) : 0.00 kN


ℹ Note:

The total gravity load reported below represents the sum of total dead load

and reduced live load considered for seismic mass calculation in the above sections.


Total Gravity Load (W) : 354780.69 kN



8. RATIO OF BASE SHEAR TO GRAVITY LOAD

ℹ Note:

The following values represent the ratio of maximum base shear to total gravity load,

as calculated in the above sections.


These percentages indicate the magnitude of seismic forces applied in the model

relative to the total vertical load of the structure.


This ratio provides a quick understanding of the proportion of lateral forces

acting on the structure with respect to gravity loads.


These values may also be cross-checked manually using the seismic coefficient

as per IS 1893, given by (Z/2) × (I/R) × (Sa/g),

based on the fundamental time period of the structure.


Vx(max) / W : 0.0266 (2.66 %)

Vy(max) / W : 0.0239 (2.39 %)

Vz(max) / W : 0.0000 (0.00 %)



9. RESPONSE SPECTRUM LOAD CASES DETECTED

ℹ Note:

The following response spectrum load cases are identified in the model.


In the subsequent sections, the base shear obtained from these load cases

will be reviewed, and scaling of the response spectrum loads will be checked.


Response Spectrum Load Case : RSX

Response Spectrum Load Case : RSY



10. MAXIMUM BASE SHEAR FOR RESPONSE SPECTRUM LOADS

ℹ Note:

The following values represent the maximum base shear obtained

from all defined response spectrum load cases in the model.


These are envelope values, indicating the maximum response

in X, Y, and Z directions across different response spectrum load cases,

and do not correspond to any individual load case.


Vx(RS max) : 4976.00 kN

Vy(RS max) : 4876.64 kN

Vz(RS max) : 0.00 kN




11. RESPONSE SPECTRUM SCALING CHECK

ℹ Note:

In this section, the maximum base shear obtained from response spectrum load cases

is compared with the maximum base shear from equivalent static analysis.


Based on this comparison, the response spectrum scaling check is performed.


This check is essential to ensure proper consideration of seismic forces,


Static Base Shear X : 9432.46 kN

Static Base Shear Y : 8476.88 kN


Response Spectrum Base Shear X : 4976.00 kN

Response Spectrum Base Shear Y : 4876.64 kN


Scaling Check Criterion :

Response spectrum base shear should not be

less than equivalent static base shear.


⚠ WARNING : Response spectrum scaling not satisfied.

➜ Recommendation : Apply a suitable scale factor so that the response spectrum base shear

is not less than the equivalent static base shear as per code requirements.

The scaled response spectrum forces should be used only for strength design.


Response spectrum load cases defined exclusively for drift evaluation

do not require scaling, provided they are not used for strength design.




12. VERTICAL SEISMIC FORCE CHECK

ℹ Note:

In this section, a check is performed to verify whether vertical seismic force is considered in the model.


⚠ WARNING:Vertical seismic force not detected.

➜ Recommendation : Check whether vertical earthquake load

is required as per IS 1893.



13. 65% MASS PARTICIPATION CHECK | TORSION MODE CHECK

ℹ Note:

In this section, the mass participation of initial translational modes

in X and Y directions is evaluated.


The position of torsional mode shapes is also reviewed

with respect to the translational mode shapes

to identify any irregular behavior.


ℹ Note:

Classification of modes :

Mode classification is performed based on mass participation

in translational (UX, UY) and rotational (RZ) directions.


Pure Translational Mode :

A mode is classified as a pure translational mode when

mass participation is dominant in a single translational direction

(UX or UY), while participation in rotational direction (RZ)

and the other translational direction remains negligible.


Mixed Mode :

A mode is classified as a mixed mode when there is

significant mass participation in translational direction(s)

along with noticeable participation in rotational direction (RZ),

or when participation is distributed across multiple directions.


Torsional Mode :

A mode is classified as a torsional mode when mass participation

is dominant in rotational direction (RZ), while participation

in translational directions (UX and UY) is negligible.


Other Modes :

Modes having negligible mass participation in both

translational and rotational directions are classified

as 'Other' modes in this document.


Mode Classification Summary :

Mode 1 → Mixed (Translation + Torsion) | 3.75 sec

Mode 2 → Mixed (Translationa X & Y) | 3.2 sec

Mode 3 → Mixed (Translation + Torsion) | 2.27 sec


First three translational modes used :

Mode 1

Mode 2

Mode 3


Cumulative participation :

UX : 0.68*100 (%)

UY : 0.71*100 (%)



✔ Result: PASS

65% of mass participation is achieved

in both the directions.


⚠ WARNING: Mixed mode detected among early modes.

➜ Recommendation : Review the plan stiffness distribution,

mass–stiffness eccentricity, structural symmetry,

and diaphragm modelling to minimize unintended

torsional response in the structure.



14. CLOSELY SPACED MODES CHECK

ℹ Note:

In the following section, the closely spaced modes check is performed

considering only the first three mode shapes.


However, if higher modes exhibit significant mass participation,

they should also be reviewed for potential closely spaced behavior.



Modes considered :

Mode 1 : 3.75 sec

Mode 2 : 3.2 sec

Mode 3 : 2.27 sec


Required minimum separation : 10%


✔ Result: PASS

Message : Modal separation greater than 10%.



15. 90% MASS PARTICIPATION CHECK

ℹ Note:

In this section, the cumulative mass participation in X, Y, and Z directions

is evaluated.


A minimum mass participation of 90% is required in each direction

as per code recommendations.


Mass participation has a direct influence on the accuracy of seismic force estimation,

and hence it is essential to achieve at least 90% participation in all directions.


Further recommendations are provided based on the results of this check.


Total modes considered : 30

Maximum frequency achieved : 11.27 Hz

Modal analysis type : Eigenvalue Analysis


Cumulative Mass Participation :

UX : 98 %

UY : 98 %

UZ : 0 %


Minimum required : 90%


Number of modes required to reach 90% mass :

UX : Mode 10

UY : Mode 9

UZ : Mode | Not reached


⚠ WARNING: Vertical seismic force is absent.

➜ Recommendation :

Verify whether vertical seismic force is required as per IS 1893 provisions.


If applicable, ensure that vertical mass is included in the Mass Source definition

by enabling the 'Include Vertical Mass' option in the model.


If vertical mass is already enabled, consider increasing the number of modes

to ensure adequate mass participation in the vertical direction.




16. TORSIONAL ECCENTRICITY CHECK RESULTS

ℹ Note:

IS 1893 Torsional Eccentricity Requirement :

As per IS 1893 (Part 1)-2016, torsional effects

shall be considered using two eccentricity

conditions for each horizontal direction.


Therefore, a minimum of two response spectrum

load cases in X direction and two load cases

in Y direction should be defined to represent

positive and negative torsional eccentricity.


To account for eccentricity as per IS code,

override diaphragm eccentricity values must

be specified in the software.


In this section, a check is performed to verify

whether the required override eccentricity

values have been properly defined in the model.


Response Spectrum Cases Detected :

RS Case : RSX

RS Case : RSY



⚠ WARNING : Torsional eccentricity override not detected

for Response spectrum load case in X direction.

⚠ WARNING : Torsional eccentricity override not detected

for Response spectrum load case in Y direction.



17. SUMMARY OF WARNINGS

ℹ Note:

This section provides a consolidated summary of all warnings

identified in the report for quick reference.


Each warning listed below corresponds to a specific check

performed by this application.

For detailed explanation, associated calculations, and

recommended actions, refer to the respective sections

in the report.


⚠ 1. WARNING : Vertical mass is absent.

⚠ 2. WARNING : Response spectrum scaling not satisfied.

⚠ 3. WARNING:Vertical seismic force not detected.

⚠ 4. WARNING: Mixed mode detected among early modes.

⚠ 5. WARNING: Vertical seismic force is absent.

⚠ 6. WARNING : Torsional eccentricity override not detected

⚠ 7. WARNING : Torsional eccentricity override not detected



18. IMPORTANT NOTE

This report provides a quick automated review of selected aspects of the ETABS structural model.

The information presented here is intended only as preliminary guidance to help identify

potential areas that may require further attention during model review.


This tool does NOT replace a detailed engineering review of the structural model.

Only a limited set of checks are currently implemented, and engineering judgement

should always be exercised while interpreting the results.


The purpose of this tool is to assist engineers in identifying critical modeling aspects

and to help focus attention on specific areas of the model.


The logic implemented in this tool will continue to be refined and expanded

based on feedback received from practicing engineers.


For suggestions, queries, or feedback, please contact :

apps@sqveconsultants.com





Total processing time of modal verification tool : 1.187 seconds