www.sefindia.org

[jaswant_n_arlekar]

Dear Colleagues:

Welcome to the e-conference for Discussion on New BIS document SSD-II 06 (19914) : REQUIREMENTS FOR STRUCTURAL DESIGN AND PROOF CHECKING CONSULTANCY SERVICES FOR STRUCTURES.


The topic of this thread is:
Applicability of the standard




The country has a very large spectrum of types of designs (buildings, industrial structures, bridges, tunnels, dams, roads, etc.). The expertise required for these varied applications are significantly different. 

Should this standard acknowledge the variation in applications and types of construction to enable informed decision by the Owner? 



I will be moderating the discussions of this topic/thread. I request you to send/post inputs as close as possible to the topic/thread. This will help in the final compilation and consolidation of the discussions. 


Thank you, and looking for a spirited and effective e-conference.


Jaswant N. Arlekar 

Posted via Email

[JVCSNL]

Should this standard acknowledge the variation in applications and types of construction to enable informed decision by the Owner?


The answer to this question is yes. Each industry has its own peculiar requirements and not all engineers are expert in each of the engineering application. Hence, prior or similar experience is necessary while appointing the consultant.  

Possible grouping can be as follows: (https://www.sefindia.org/forum/viewtopic.php?t=78 was discussed about possible grouping of services at that time)

+ Non Plant Structures * Residential buildings, administration offices, canteen buildings, etc, upto 2 storey

+ Residential and commercial complexes : Structures with more than 4 stories comprising of elevators, HVAC systems, central water and drainage management, security, safety requirements

+ Industrial sheds * This category would cover structural steel storage sheds (with trusses or portals), small crane and monorails, cold storage etc.

+ Industrial structures * Plant Engineering - This category would allow to design most industrial structures like boilers, power houses, cooling towers, pipe racks and many similar structures subjected to normal, wind and seismic loading

+ Equipment/Machine Foundations * This category would comprise of critical analysis of important equipment foundation needing static and/or dynamic analysis. Even structures which need detailed and extensive seismic analysis should be listed here.

+ Transportation structures * Bridges, fly-overs, tunnels etc.

+ Hydraulic structures * canals, aqueduct, canal siphons, canal head works,

+ Structures of high importance * Dams, weirs etc.

Best Regards,

Jignesh V Chokshi

[vikram.jeet]

Applicability :
Standard to be made applicable for all structures without any exception.

Category 1 STRUCTURES
( To be designed by Prime consultant along with site visits at construction stages , AND  Proof Consultant to check along with site visits with prime consultant , so that both share responsibility)

Category 1 structures are as under :
All major structures like Bridges , small Bridges and Culverts,
  All School   Buildings , Buildings of Assembly ,  Public Buildings  Tall/ small , Residential buildings above two storeys ,
Water /Sewage / Effluent treatment Plants , OH Tanks , Underground water reservoirs , Pumping stations of water and sewage
Hydropower structures  , Dams and reservoirs
Tunnel works
Industrial structures , Power stations , Steel plants etc

All precast constructions
Low cost housing schemes for reasons of economy


More important structures can be added in list  

CATEGORY 2 STRUCTURES
( Must be designed by a competent structural engineer /  Consultant / Expert along with site visits  However proof checking  can be  optional  / skipped)

Category 2 Structures are as under  :
Buildings upto two storey height
Boundary walls
Service structures like septic tanks /soak pits
Signage structures supporting works
All sheet type roof sheds
Retaining walls

CATEGORY 3 STRUCTURES - ADDITIONS ALTERATIONS HAVING STRUCTURAL IMPACT IN EXISTING STRUCTURES
(Must be designed by a competent  structural engineer / expert / Consultant  and  to be carried with his inspection visits at site plus Proof checking on large span works  shall be essential . Proof check on small spans upto 4.5 m can be skipped.)

[vikram.jeet]

Role of Geo tech Consultant , it's soil report and recommendations need also to be addressed,  and who will proof check soil reports , which is very essential for any project safety as also economy.
We are concentrating only on str design part   but if soil report is shabby , design efforts thru prime as also proof Consultant suffer .

A proof checking GEOTECH CONSULTANT SHALL ALSO BE THERE WHO VISIT EVEN DURING FIELD INVESTIGATION , LAB TESTS , AND ALSO VETT THE SOIL REPORT GIVEN BY GEOTECH MAIN AGENCY
This will also avoid cooking of readings during field  investigations and  Lab tests.

[abhishek_prajapati]

Dear Ma'am / Sir,

Code has defined the Traditional Mode in Cl.2.1 but in further clauses it is silent about the applicability of PDC / PC for Traditional Mode.

Since the Code is not giving any information about Traditional Mode, it is understood that PDC / PC is not required for Traditional Mode.

Please clarify.

Regards

Abhishek

[Jayant Lakhlani]

Dear SEFIans

Greetings that BIS has decided to address the important issue like ‘Proof Checking of Structural Design’. Also, congratulations to SEFI for organising this E-conf.

In this mail, focus is on ‘Applicability of the standard with respect to proof checking of structural design’. The format adopted is code clause followed by views on the same.

Foreword:
The need for proof checking of structural designs has been recognized as an essential step for reinforcing the need for public safety in tandem with the rapid advancement on engineering and the fast pace of development that is happening in the country. Adding confidence and reducing risk through such a procedure is essential since it provides for risk mitigation on account of errors in the design stage and thus ensures better safety.

JL – The clause emphasizes need for structural design proof checking and intends to reduce the risk through implementation of such procedure. But, suggested content of the standard does not seem to fulfil this intent, as discussed below.


Cl. 2.1 Build and Deliver Mode (Traditional Mode) — The delivery mode in which the owner is responsible for providing the preliminary design and drawings, technical specifications, Bill of Quantities (BOQ), and detailed designs and drawings to the constructor for the execution of the works.
NOTE — The constructor is responsible to build and deliver.

JL – This mode is widely prevalent in private sector building construction (Residential / Commercial / Others) wherein a builder / developer is in a role of owner. In this sector, structural design proof checking is rarely exercised and PDC appointed by the owner is believed to follow all the statutory and regulatory requirements, including design standards. But the design prepared remains like a black box which is opened only if any mishap occurs.


Cl. 2.4 Design, Build and Deliver Mode — The delivery mode in which the owner provides the detailed scope, performance specifications and design basis report at the time of bidding to the constructor.
NOTE — The design and execution shall be responsibility of constructor.

JL – This mode is mainly prevalent in government / public sector construction (Buildings / Bridges / Water and Sewage Treatment Plants / Water tanks / Pumping stations / Tunnels) wherein a government organisation is in a role of owner. In this sector, majority of the projects are subjected to structural design proof checking. PDC is appointed by the constructor and PC is appointed by the owner.

Here, in light of above two clauses, I would like to mention that, during 2001 earthquake, in the city of Ahmedabad, 70 framed structured buildings totally collapsed and approximately 750 lives were lost. All these buildings were engineered buildings, with PDC appointed for them. All the codes required for earthquake resistant design were prevalent on date and it was a wishful belief that all the buildings are designed following them. But due to lack of proof checking of structural design, PDC were inclined to disrespect the codal requirements for various reasons and the consequence was devastating. Today, after 22 years, the situation in the private sector is not much different.

On the contrary, the loss of life and properties in the public sector construction was minimal, mainly due to implementation of design codes through a system of structural design proof checking.

So, effective structural design proof checking system, in the private sector, is need of the day.

Cl. 5.1 The owner may appoint a PC for proof checking of the structural design of the structures prepared by PDC.
JL – Here, appointment of a PC has been left to discretion of the owner. This will not make the structural design proof checking mandatory and intent of the code shall be marred.
Structural design proof checking should be made mandatory for all public as well as private sector constructions. In public sector, this is already followed for almost all constructions. In private sector, certain small constructions can be relieved from this provision and for remaining, proof checking system can be adopted for randomly selected projects, if does not become possible for all of them.

Cl. 5.2 The PC shall in all cases be always appointed by the owner so that the PC is never subservient to the Constructor/ CDC.
JL- For delivery mode as per cl. 2.4, the owner should appoint the PC. But for delivery mode as per cl. 2.1, the appointment of PC should not be done by the owner but should be done by local authority approving the project.


Cl. 6.1 Model 1— Owner Appointed PDC and PC
The owner shall directly appoint both the PDC and the PC for structural designing and for proof checking, respectively. The Good for Construction (GFC) drawings shall be issued by the PDC to the owner after approval by the PC as shown in Fig.1.
JL- As discussed for cl. 5.2, when a PDC is appointed by owner, the PC should be appointed by project approving authority.

These are my views to take a step towards effective implementation of a good proof checking system. If such effective proof checking system is there, all the requirements and responsibilities of PDC shall automatically be fulfilled.

Regards.

Jayant Lakhlani
For
Lakhlani Associates



From: jaswant_n_arlekar <forum@sefindia.org>
Sent: 29 August 2022 08:08 AM
To: econf@sefindia.org
Subject: [ECONF] Applicability of the standard



Dear Colleagues:

Welcome to the e-conference for Discussion on New BIS document SSD-II 06 (19914) : REQUIREMENTS FOR STRUCTURAL DESIGN AND PROOF CHECKING CONSULTANCY SERVICES FOR STRUCTURES.


The topic of this thread is:
Applicability of the standard




The country has a very large spectrum of types of designs (buildings, industrial structures, bridges, tunnels, dams, roads, etc.). The expertise required for these varied applications are significantly different.

Should this standard acknowledge the variation in applications and types of construction to enable informed decision by the Owner?



I will be moderating the discussions of this topic/thread. I request you to send/post inputs as close as possible to the topic/thread. This will help in the final compilation and consolidation of the discussions.


Thank you, and looking for a spirited and effective e-conference.


Jaswant N. Arlekar

Posted via Email

[VPandya]

Dear Er . Vikram Jeet,
Iin Inda I noticed that Geotech report do not have Settlement calculations of RAFT Foundation and Pile Foundation sellement calculations . TO BRING THE POINT HOME I GIVE THIS EXAMPLE , HOW IMPORTANT GEOTECH REPORT IS TO THE STRUCTURE :

58 STORIES BUILDING  ( LEANING TOWER SAN FRANCISCO ) IN CITY OF SAN FRANCISCO , CA , USA .

We have discussed this failure in SEFI . Soil Report should be good and recommendations followed or you need about 1 million dollar  fo fix it. Thank God no one died .

I gave seen Structural Engineers on a project in India reading SOIL BORING LOG to find out SAFE BEARING pressure , this should be given by Geotech Consultant . He should do the Raft settlements calculations based on the FOUNDATION REACTIONS given by PDC . In USA geotech report have one or two pages with title  " FOUNDATION  DESIGN ."

Regards,

Vaudeo Pandya  P.E.
Structural Engineer

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