Assignment 3

ASSIGNMENT 3 49115 FAÇADE ENGINEERING 1

QUESTION-1

SHASHANK SHEKHAR MISHRA 22/04/y Student Id: 12174710




QUESTION-2

Good practice dictates that professional should design enough leeway into detail to

allow acceptable tolerances.

Tolerances are the maximum permissible deviation, which in the construction is

around +/- 25mm. But, in the façade installation the glazing unit are so accurate that

there is tolerance of only 2-3 mm. So accommodate these tolerances are important for

the proper functioning of structure and curtain wall as a whole unit.

In order to accommodate these tolerances we have to calculate, check the correct

value and verify wether possible to install the façade without any failure.

The bracket and fixing along with channel cast-in concrete are the major component

in façade installation and used for accommodating the erection tolerances.

Bracket and fixing are used to attach the curtain walls to the supporting structure and

transfer the horizontal and vertical forces to the structure without any failure. Support

bracket is responsible for vertical tolerances where as restraint connection limits the

horizontal force on curtain wall.

All brackets provide adjustment in three directions to overcome dimensional

variation.

Halfen channel is in-caste concrete channel and the fastening system is fixed with bolts

to this component that is almost totally submerged by the concrete of the floor slab

and moreover allows the horizontal in-plane tolerances control of the façade.

Support bracket has to resist against every loads that the façade is subjected to, from

its self-weight and variable loads until the horizontal wind and seismic loads.

Consequently its verification is the most important one in the fastening system

analysis. Furthermore, its slotted holes, it allows the horizontal out-of-plane tolerances

control of the façade. It must be adjusted to correct any misalignment within 2mm limit.

The packers can be used for the installation of the façade bracket for the correct placement where the

built slab is lower than designed slab.

The vertical channel in the fastening system directly attached to the mullion in the

façade. It allows the vertical tolerances control of each unit, through the fastening or the loosening of

the vertical screw that passes in it and acts on the hook component.

The permissible limit of movements and tolerances present at time of construction is

checked and treated by adjusting bracket and channel to correct any misalignment.



The vertical joints must accommodate the horizontal movement whereas vertical

movement must be counter by the horizontal joints.

Sometimes greater or smaller manufacturing tolerance are requires, the specification

of each and every member are clearly stated on the specification order. There also

provision to accept the unit under the permissible tolerance for installation purpose.

As Façade consultant, the accommodation of tolerance is good and save money but

we have to sure about doing work, the predicted consequences and the cost related

responsibilities are clearly defined before fixing these type of work.

The figure below show how bracket accommodate movement.



QUESTION-3

QUESTION-3

The base structure will continue to undergo displacement during the life of the

building due to variation in live load and of the concrete structural elements.

Curtain wall system looks simpler to the laymen but it is more complex thing to

install. For achieving structural adequacy, which is prime motive in the construction

industry, it has to be accommodating all the movements due to loads acting on

building and thermal effects. Because structural failure may jeopardize human life,

the structural integrity of the wall may be said to be the primary concern in its design.

Long-term movement in the building, which our façade needs to accommodate:



ACCORDING TO NSSS:

Maximum Permissible horizontal Deflection= Span/250



VERTICAL DEFLECTION

VERTICAL DEFLECTION-

MAXIMUM DEFLECTION = 25 mm

MAXIMUM COLUMNN SHOERTENING = 2.2mm

LIVE LOAD= 5mm

Dead Load= 4mm

Above are the maximum and provided values; these are the permissible deflection

which our bracket and joints need to counter.



THERMAL EFFECTS

Temperature creates two kinds of problems due to solar heat in curtain wall design

that is the expansion and contraction of materials and the necessity to control the

passage of heat through the wall.

Thermal movement of cladding due to temperature fluctuation= +3.8mm/-3mm.

MAXIMUM OPENING AND CLOSING MOVEMENT = -/+ 32 mm.

A most important consideration in designing aluminum curtain wall is necessary to

ample provision for movement. No building is a static thing, and this goes double for

metal curtain wall. Movement is constantly taking place, such as movement within the

wall components themselves, relative movement between the components, and

relative movement between the wall and building frame to which it is attached. These

movements are caused not only by temperature changes, but by wind action, by

gravity forces and by deformations or displacements in the building frame. To

disregard such movements in designing the wall is an urgent invitation to trouble.



QUESTION-4

DESIGN FOR GLASS:


ASSIGNMENT 3 49115 FAÇADE ENGINEERING

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DESIGN FOR MULLION



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Male Mullion

FEMALE MULLION



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QUESTION 5

DOCUMENT YOUR DESIGN



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Documents

Assignment 3