Structural Engineers Forum of India

SEFI General Discussion :: RE: Some general view

vikram.jeet — Tue, 25 Aug 2026 06:48:11 GMT

Author: vikram.jeet
Posted: Tue Aug 25, 2026 6:48 am (GMT 0)

CONCRETE BLOCK FOUNDATION FOR  POLES, HIGH RAILINGS, SIGNAGES ETC

THIS FOUNDATION OF CONCRETE  BLOCK IS SUBJECT TO MOMENTS DUE TO HORZONTAL FORCES  ( WIND IN CASE OF POLES & SIGNAGES, , AND HORIZONTAL RAILING LOADS BASED ON NORMAL / OVERCROWDING) . BUT THE  DEAD WEIGHT OF STRUCTURE PROVIDING STABILITY IS NEGLIGIBLE, AND WT OF CONCRETE BLOCK CAN PROVIDE STABILITY BUT IT'S SIZE VIS A VIS LIGHT WT STRUCTURE, ALWAYS BECOME EYESORE TO ALL IN EXECUTION, AND EVEN DESIGNER HIMSELF ALWAYS SEEN FIGHTING WITH CALCULATIONS TO MINIMIZE THE SIZE.

RELIEF IN MOMENT IS GENERALLY TAKEN BY DESIGNER IN FORM OF PASSIVE ( LESS ACTIVE) SOIL RESISTANCE IN FRONT, BUT EVEN THEN, SUCH STRUCTURES DEMAND LARGER BLOCK SIZE THAN EXPECTED.

I THINK, IN SUCH SITUATIONS, IF PERMITTED BY THE PROOF CONSULTANT   ONE CAN ALWAYS CONSIDER SIDE FACE FRICTION PROVIDING SOME SMMOUNT OF STABILIZING MOMENT DUE TO DOWNWARD FRICTIONAL RESISTANCE . THE FORCE OF FRICTION = FRICTION COEFFICIENT *  HORIZONTAL EP AT REST * BLOCK DIMENSION ( SIDE) *2 ( BOTH SIDES) ,,  EP REST TAKEN SINCE SIDE FACE MOVEMENT NOT THERE IN THAT DIRECTION.

ALSO AT BACK OF WALL ( IN CASE ACTIVE PRESSURE TAKEN AS PER RANKINE) , THE FRICTION FORCE ON WALL EXERTED BY WEDGE  WT. HAVING  ANGLE ( 45 - PHI /2) WITH VERTICAL SURFACE OF BLOCK CAN BE TAKEN . IN CASE COULOMB THEORY USED, THEN ACTIVE EP PRESSURE AT BACK OF WALL INCLUDE THIS FRICTION .
THE FRICTION DOWN FORCE =  WEDGE WT. X  TAN PHI
( VALUE OF PHI BE TAKEN UNDER WET CONDITIONS AS 75% OF PHI)

PASSIVE LESS ACTIVE EP -  AT FRONT, THE BLOCK FOUNDATION IS STABILIZED BY PASSIVE EP, WHEREAS AT BACK OF WALL ACTIVE EP ACTING SIMULTANEOUSLY.

JUST DISCUSSED AS FOOD FOR THOUGHT ON STABILITY OF CONCRETE BLOCK FOUNDATION

SEFI General Discussion :: RE: Some general view

vikram.jeet — Sun, 23 Aug 2026 07:39:05 GMT

Author: vikram.jeet
Posted: Sun Aug 23, 2026 7:39 am (GMT 0)

QUANTITY SURVEY

STEEL STRUCTURES -  ON AN AVERAGE

FABRICATION AND ERECTION WORKS - LABOR OUTPUT

FABRICATION  - 20 KG PER MAN HOUR

ERECTION -   30 KG PER MAN HOUR

WELDER OUTPUT

ROD CONSUMPTION  -     5 KG  PER 8 HR SHIFT PER WELDER

WELD LENGTH  -  PER WELDER

FILLET  ( 4-6mm )  -  25 METERS  PER DAY OF 8 HOUR SHIFT

BUTT WELD ( SINGLE PASS) - 12.5 METERS PER DAY
MULTI PASSES -  3 METERS PER DAY

PIPE JOINTING - 6.25  METERS PER DAY

SEFI General Discussion :: Modal Participation

prabhat67 — Thu, 20 Aug 2026 04:37:13 GMT

Author: prabhat67
Subject: Modal Participation
Posted: Thu Aug 20, 2026 4:37 am (GMT 0)

I am reviewing a structure 35m hight with 12m grid in Mumbai. Due to some contraints the modal participation as recomended by code 65% is not achieved .. but many iterations we could achieve 60%. Is it mandatory and what is guideline in this scenario.

SEFI General Discussion :: [Sponsored Post] Stability & Torsional Warping: Why a 6 DOF Buckling Check Might Not Be Enough

admin — Tue, 18 Aug 2026 11:06:25 GMT

Author: admin
Subject: [Sponsored Post] Stability & Torsional Warping: Why a 6 DOF Buckling Check Might Not Be Enough
Posted: Tue Aug 18, 2026 11:06 am (GMT 0)

Hello everyone,

Continuing our introduction of Dlubal Software to the SEFI community, this week we want to talk about a blind spot that shows up often in steel hall and portal frame design: lateral-torsional buckling that a standard stability run does not catch.

Here is the pattern. You model a steel hall, run a stability analysis, and the standard 6 DOF solver returns a critical load factor for the governing load combination. In a lot of cases, that result points to in-plane or out-of-plane flexural buckling, and the check looks complete. But if the static analysis also shows bending moments in the main beams, there is a real lateral-torsional buckling risk that the 6 DOF solver alone will not flag.

RFEM 6 addresses this with the Torsional Warping (7 DOF) add-on, used alongside the Structure Stability add-on:

Cross-section warping is added as a 7th degree of freedom directly in the same global model, so there is no separate program or re-modeling step
The calculation runs on the entire structure, so the stiffness of adjacent members and the defined support conditions are considered automatically
Warping is associated with individual members by default and assumed unhindered at member ends. If you need warping to transfer between connected members, you define a set of members, and if you need to represent actual end restraint, you use Member Transverse Stiffeners to define warp springs
Because the 7 DOF connection point sits at the cross-section centroid rather than the shear center used in the 6 DOF case, member eccentricities or rigid members are used to keep load application points consistent with the real structure

We would rather show how a specific problem gets solved than just describe features in the abstract, so: how are you currently checking for lateral-torsional buckling in your portal frame or industrial building designs? A separate hand calculation, a different software module, or something else?

Full details on RFEM 6, Structure Stability, and Torsional Warping: https://ad.sefindia.org/dlubal-torsional-warping-forum-w2

Want to see how these checks help you avoid the most common steel design mistakes and meet us for the first time in India? Join our free live webinar: "Top 7 Structural Steel Design Mistakes Every Engineer Should Avoid" August 20, 2026 | 16:00 � 17:00 IST | Free Presented by Rahul Telang

Register here: https://ad.sefindia.org/dlubal-webinar-forum-w2

Looking forward to the discussion.

Best regards,

Rahul Telang
Dlubal Software
r.telang@dlubal.com

Sponsor Contact and address : Phone: +91 9168875401 Email: r.telang@dlubal.com KODESK Co-working, 201, 2nd Floor, 45 Baner Street Pune, Maharashtra�411045

This is a sponsored Media Announcement [Advertisement]. Sponsor assumes responsibility for the content below. To communicate further in this regard, use the contact information provided within this message.

SEFI General Discussion :: RE: Support condition for a continiously Wall supported beam

vikram.jeet — Fri, 14 Aug 2026 23:19:56 GMT

Author: vikram.jeet
Posted: Fri Aug 14, 2026 11:19 pm (GMT 0)

Support condition for a BEAM embeded IN BK WORK FOR CONSIDERABLE LENGTH

EXTENT OF FIXITY DEPENDS ON
EMBEDDED LENGTH
BRICK WORK HEIGHT OVER IT AT SUPPORT

BUT FOR ALL PRACTICAL PURPOSES, BETTER ASSUME PARTIAL FIXITY
MID SPAN MOMENTS OF THE ORDER OF wL^2 / 10

Support Moments = wL^2 / 24 to w L^2/20

Accordingly, STAAD INPUT

SEFI General Discussion :: Support condition for a continiously Wall supported beam

hishamajmalpc — Fri, 14 Aug 2026 19:44:03 GMT

Author: hishamajmalpc
Subject: Support condition for a continiously Wall supported beam
Posted: Fri Aug 14, 2026 7:44 pm (GMT 0)

For a beam in a Load bearing structure supported on masonry wall for a considerable length and have masonry above its support also (as in continious lintel ), what will be the right support condition to assume? Any guidelines on choosing between fixity vs Simple support vs partial fixity?

SEFI General Discussion :: [Sponsored Post] Introducing Dlubal Software to the SEFI Community: Steel Design with RFEM 6 (incl. IS 800:2007)

admin — Tue, 11 Aug 2026 09:07:17 GMT

Author: admin
Subject: [Sponsored Post] Introducing Dlubal Software to the SEFI Community: Steel Design with RFEM 6 (incl. IS 800:2007)
Posted: Tue Aug 11, 2026 9:07 am (GMT 0)

Hello everyone,

We're Dlubal Software, introducing ourselves to the SEFI community as we expand into India.

A problem we hear often from structural engineers working on industrial buildings and warehouses: the main frame is hot-rolled steel, the purlins and girts are cold-formed, and checking both often means switching between separate tools or spreadsheets, with results that then need to be manually reconciled.

RFEM 6, our structural analysis and design software, addresses this with a modular approach:

One FE model for the full structure: frames, purlins, girts, connections, and foundations
The Steel Design add-on performs member checks for both hot-rolled and cold-formed sections directly on that model
Hot-rolled members are checked against IS 800:2007 (Indian Standard for General Construction in Steel), and cold-formed members against AISI S100
Additional standards are available too, including Eurocode 3 and AISC 360, useful for projects with an international customer or design partner
The same modular system extends to Steel Joints (connection design) and RSECTION (custom cross-sections) as a project grows in scope

Over the coming weeks we'll go deeper into stability and torsional warping, steel connection design, and cold-formed section design.

We'd rather start with something useful than a pure product pitch, so: what's the biggest friction point you run into when designing metal buildings today? Code compatibility, connection design, or something else? We'll try to address it in a future post.

You can find full details on RFEM 6 and the Steel Design add-on at https://ad.sefindia.org/dlubal.

If you'd like to see the workflow firsthand, we're hosting a free webinar: "Top 7 Structural Steel Design Mistakes Every Engineer Should Avoid."

Register here: https://ad.sefindia.org/dlubal-webinar-forum-w1

Looking forward to the discussion.

Best regards,

Rahul Telang
Dlubal Software
r.telang@dlubal.com

Sponsor Contact and address : Phone: +91 9168875401 Email: r.telang@dlubal.com KODESK Co-working, 201, 2nd Floor, 45 Baner Street Pune, Maharashtra�411045

This is a sponsored Media Announcement [Advertisement]. Sponsor assumes responsibility for the content below. To communicate further in this regard, use the contact information provided within this message.