Designing of Building Structure: Activities that can adversely impact business
Designing of building structure for
any building includes designing columns, foundation, stilt floor,
beams, slabs, retaining walls, levels, column schedules, staircases, terraces,
Sewage Treatment Plant, harvesting pits, façade areas of any building
Characteristics of a Robust building structure are:
Inputs that contribute to making a good structure
design include the following:
1 Proposing the right choice of strong
materials in terms of specifications while optimizing costs:
Types of materials for use |
Key specifications of building
materials (as required by customers and National/international Quality
standards) |
TMT bars, Structural steel, etc |
strength, elongation, fatigue resistance,
etc |
Cement |
setting time, strength, moisture, density,
fineness, chemicals, etc |
RMC |
workability, mechanical strength, density,
durability, etc. |
Shuttering materials |
strength, durability, rigidity, etc |
Scaffolding materials |
compression strength, tensile properties, etc. |
Applicable hardware |
size tolerances, the material used, etc |
Joineries |
strength, flexibility, toughness,
appearances, etc |
And so on |
|
2
Incorporating, in Structure related design
& drawings, good practices for construction or & installation of the
following as per applicable Quality standards:
i)Sub-structure
· Excavating
· Dewatering
· Earthmoving
· Preparing PCC
· Preparing RMC
· Bending & preparing TMT
bars
· Constructing & laying the standard
foundation
· Laying the piled foundation
· Waterproofing,
·
Concreting & masonry work in foundations
ii) Superstructure
·
Scaffolding
·
Shuttering
·
Constructing frameworks for all columns, beams, etc
·
Constructing upper floor
·
Constructing roof structure
·
Constructing stairs/ramps
·
Constructing external walls
·
Constructing external windows &external doors
·
Internal walls & partitions
·
Internal doors
·
And so on
3 Essential technical steps/activities to facilitate building quality in the designing process for Structure include:
· Drawing grids
· Defining materials
· Defining
section properties
· Drawing objects in the structural engineering
models
· Developing plans and elevations
· Defining & Selecting loads
· Soil-Structurer Interaction
· Structural Dynamics
· Earthquake analysis
· Wind and seismic loads as per National standards
· Value engineering
And so on
Software like ETAB
can facilitate carrying out such activities accurately &
efficiently.
Validation of design
Validation of developed design by carrying out
structural analysis by an independent proof consultant is desirable, and the scope
usually includes:
· Linear Static and Dynamic Analysis of RCC
Structures, Design and Detailing of RCC Beams, Columns, Slabs, and Foundations,
Composite deck and Parametric Modelling, Modal Frequency of a Structure, Wind
Loads on RCC structure, FEM Analysis, and Design
and so, on
Seven stages for creating the design
of Structure
Design activities vary considerably from
company to company, but generally, there are seven stages
to designing the Structure for
buildings, as below. Whatever designing processes and software are used, designing
must result in developing Robust designs by accomplishing the following:
·
Build designs
that are comprehensive, accurate
·
Contributes to building
quality in construction by incorporating national and international quality
standards in BOQ/material specifications and construction processes
·
Integrates
statutory and safety requirements in the designs and drawings
·
Optimise project
costs
·
Enables efficient
delivery of designs & drawings
·
Incorporates
maker-checker step in each design stage through the implementation of segregation of duties concept
The seven stages are:
1.
Developing Concept Design
2.
Vetting of design
3.
Developing GFC and specifications
4.
Tender development
5.
Obtaining a Structural stability certificate
6.
Making Cost estimates for the entire Structure
7.
Issuing “As-built drawings.”
In the activities listed
below, those marked ‘*’ reflect those activities which can have adverse
statutory implications.
Stage 1 activities that
can adversely impact business
·
Not obtaining and
not incorporating inputs (like Purpose
of building, Features of Structure, Structural safety requirements
vis-à-vis zone in which building is to be constructed, Overall dimensions and
FAR, overall building Plan and elevation, etc.)
from other interfacing functions like selling,
architects, and construction into the Structure design
· Not
assigning competent designers*
· Using
unlicensed software while developing a concept design for Structure *
· Making
compromises while vetting structure design, by skipping or compromising on structure
designs and drawings aspects such as below.
· Tolerances
on specifications of materials and workmanship
· Statutory code-related requirements for Structure
*
· National
and international standards for quality
· Raw
Material (TMT bars, Cement, or RMC) sizes and specifications,
the
lower factor of safety*
· Proposing
low cost /low strength raw materials
· Bribing
mandatory Agencies which approve the structure design calculations
relevant for issuing structural stability certificates*
Stage 2 activities that can adversely impact business
· Colluding
the principal architect and proof consultant to accept the consultancy design
work with incorrect design calculations (e.g., TMT bars sizes and Grades like
Fe415, Fe 550, RMC (M20, M30, M40, etc., Cement-OPC 43, OPC 53, PPC, etc.) in
return for some favours.
· Assigning
the same designer to validate the design, who initially developed it, thus not
implementing the segregation of duties concept*
Stage 3 activities that can adversely impact business
· Making GFC drawings that are not aligned to
design calculations
· Architect
Insisting on specific brands of TMT bars and Cement or RMC in collaboration
with vendors of brands and getting financial favours. *
· Compromising
specifications for developing samples in collaboration with vendor/contractor.
·
Releasing of
design and drawings and issuing these to structure contractor at a site
without any control
·
Not shredding or
deleting waste designs/drawings and misuse of this
Stage 4 activities that can adversely impact business
· Making
tenders that are not comprehensive vis-à-vis technical specifications or are
deliberately stated vaguely for subsequent manipulations amongst the architect
and contractor with ulterior motives.
· In
the tender, the Structural Engineer/architect includes names and brands of
specific materials only for pre-identified /preferred vendors of the Structural
Engineer/Architect in return for commission/kickback from such vendors. *
· Architect recommending only a single source
for many BOQ materials and thus leaving very few options with the project
materials team to negotiate prices aggressively in return for commission
/kickback to an architect from such vendors. *
· Inspection requirements concerning inputs such
as TMT bars, Cement, and RMC are not comprehensive
· Tender
drawings not incorporating applicable quality standards for all works, and applicable
Statutory requirements, particularly w.r.t safety. *
Stage 5 activities that can
adversely impact business
· Bribing
the certifying officials to get a Structural Stability Certificate in
due course. *
Stage 6 activities that can adversely impact business
· Computing costs based on thumb rules rather
than the first principal basis vis a vis costs of TMT bars, Cost of Cement,
Cost of RMC, and other structural elements relevant as also costs of
shuttering, cost of scaffolding, costs of joinery, etc. and cost of
labour/fabrication for each part of the Structure, floor wise, and each
building.
Stage 7 activities that can adversely impact business
·
Preparing “As-built drawings” shown as
aligned to Structure Stability certificate, but actual physical construction of
the built-up Structure is in deviation to the “as-built drawings” in terms of
TMT Bar sizes, RMC, safety factor and construction materials used, etc.