Building transportation is a system capable of conveying people to heights in safety and comfort.
Hand powered lifts or hoists in various forms have been in use since the days of Pyramid construction in Egypt in 2600 BC
In china hand powered winches were used to draw water as far back as 236 BC
In 1853 Harper’s magazine remarked on the introduction of steam elevator by which an indolent or fatigued or aristocratic may be born up to the third, fourth or fifth floor
Same year Eisa Otis established a company to manufacture hoists and was able to demonstrate the new device in NEW YORK City
Today the lifts have the best safety record of nay form of transportation systems and its installation in buildings is accepted as an essential requirement.
Principle of interior circulation
GENERAL
It is important to consider the principles concerning vertical transportation to analyze the effectiveness of devices which provide vertical transportation’
The circulation of people in i the interior of a building is a complicated activity. It is effected by number of factors
· Mode:: horizontal and vertical movement
People will be generally be walking horizontally, except where the are using passenger conveyers. The will change mode from horizontal to vertical movement, in order to reach a higher or lower level. To do this they will use stairs, moving walks and ramps (Passenger conveyers, escalators or lifts)
· Movement Type: natural or mechanically assisted
People will move naturally when walking, and be mechanically assisted when using moving walks and ramps (Passenger conveyers, escalators or lifts)
· Complications: human behavior
The movement of people around building is complex – because humankind is complex. Individuals have their own concept of routes: there own purpose for travel: their own level of urgency: her own characteristic of age of age ,gender, culture, handicap etc. There is unpredictably in the human behavior
The interior circulation of a BUILDING MUST BE DESIGNED:
· To consider all circulation routes
These include principle and secondary circulation areas, escape routes, service routes and waiting areas
· To provide clear and obvious routes
Pedestrian should be able to see the route to take perhaps assisted by good color coded signs
· To ensure that the circulation patterns are rational
An example is the avoidance of pedestrians passing through a lift lobby, where other persons are waiting
· To ensure incompatible types of circulation do not coincide
This refers to goods trolleys being pushed across a pedestrian mall in a shopping center or sterile/no sterile movement in a hospital
· To minimize the movement of people and goods
This would bring associated activities together eg. Sales & marketing: personnel & training
The design and allocation of portals (entrances. doorways, gates etc),corridors, stairs and mechanical handling equipment (ramps , escalators. Lifts etc.) must be coordinated in such a way that
*`free flow of people goods and vehicles
* occupy the minimum allocation of space
* Bottle necks are prevented
The efficiency of the interior circulation is dependant of the building shape tall/slender and low/squat buildings are inefficient. The ideal shape IS COMPACT
The factors which effects the circulation efficiency are:
· The relative location of rooms
· The relationship of major spaces with entrances and mechanical elements
· The importance of journey undertaken
Human Factors
The physical dimensions of the human body obviously vary very widely, females are generally smaller than the males. The space an individual occupies depends on how the person is clothed and what they might be carrying.
A typical template is shown below and is considered to be an eclipse of dimensions 600 mm x 450 mm and occupying 0.21 m2.
LEVEL | Density |
Persons/ m2 | |
Desirable | 0.4 |
Comfortable | 1.0 |
Dense | 2.0 |
Crowding | 3.0 |
Crowded | 4.0 |
There are number of factors that effect pedestrian movement
1,0 Pedestrian dimensions
2.0 Pedestrian velocities
3,0 Uni-directional/ bi-directional flow
4.0 Cross flow
5.0 Patterns of waiting
6.0 Site & Environmental conditions
7.0 Statutory requirements
Desirable 0.4 persons/m2
allows individuals to walk more or less where they want to go orstand without any interference from other individuals
Comfortable 1.0 persons/m2
Allows individuals to walk with some deviations , without interference with other people
Dense 2.0 persons/m2
Individuals who are working must take care not to collide with other people
Crowding 3. 0 persons/m2
It is possible to walk as a shuffle
Crowded 4 .0 persons/m2
Walking is almost impossible
CIRCULATION
DEFINITION:
Circulation is the act of passing from place to place.
People flow like liquid, following the line of least resistance and great attraction.
CIRCULATION IN AN SHOPPING CENTER
As an example in case of a Shopping Center or Mall, the former must be enabled and latter encouraged..
The interior circulation of people in buildings is a complicated activity. Therefore the interior movement of people must be designed to consider all circulation routes to allow for the free flow of people, goods and vehicles with the minimal wastage of space and the prevention of bottle necks.
In case of an shopping center , however some of the good design criteria set out may be intentionally violated, as they are not necessarily conducive to the selling of goods. For instance, having attracted shoppers into a store, all routes except the exit from the store, may be clearly marked (Emergency exits exempted). The free flow of people may be deliberately reduced by the introduction of display stands along the routes offering goods for sale to encourage impulse buying. Circulation may be designed to be irrational, but not obviously so, for instance with regard to escalator layouts to cause shoppers to walk around part of a floor , in order to reach the next facility, thus presenting merchandise to prospective shoppers.
No two shopping centers have the same structure, population or circulation patterns. Most shopping centers are designed to occupy two levels and some times three. Two levels are generally considered and centers with three levels often have food courts at the upper or lower levels to form an attraction and contrast to the main sales areas.
THE TEORETICAL ASPECT OF HORIZONTAL MOVEMENT
The most likely people in a shopping center will be shoppers or tourists. The most practical unit of time to be used for this environment is one hour instead of one minute.
HANDLING CAPACITY OF CORRIDORS
The equation below indicates the capacity Cc in persons per minute with a straight corridor or mall as
Cc = 60.v.D.Wc
Where:
Cc = Corridor Mall handling capacity (persons per minute)
v = Average pedestrian speed (meters per second)
D = Average pedestrian density (persons per m2)
Wc = Effective Corridor width (meters)
For example the effective with of a 5.0 meter wide Mall will reduce 4.0 meter, if a row of people are seated along one side
PEDESTRIAN FLOW TABLE
Pedestrian speed and flow for stated pedestrian density
Type of Traffic | Free Flow Design density (o.3 person per m2) | Full Flow Design density (1.4 person per m2) | ||||
Speed (m/s) | Flow rate (Person/Min) | Flow rate (Person/h) | Speed (m/s) | Flow rate (Person/Min) | Flow rate (Person/h) | |
Commuters Working persons | 1.5 | 27 | 1620 | 1.0 | 84 | 5040 |
Individual shoppers | 1.3 | 23 | 1380 | 0.8 | 67 | 4020 |
Family groups Tourists | 1 | 18 | 1080 | 0.8 | 67 | 4020 |
School Children | 1.1 - 1.8 | 18 - 32 | 1080 -1920 | 0.7 - 1.1 | 59 - 92 | 3540 - 5520 |
Minimum width for corridors to accommodate various traffic
Type of traffic | Minimum corridor width (m) |
One – way traffic flow | 1.0 |
Two– way traffic flow | 2.0 |
Two men abreast | 1.2 |
Man with bag | 1.0 |
Porter with trolley | 1.0 |
Woman with pram | 0.8 |
Woman pram child along side | 1.2 |
Man on crutches | 0.9 |
Wheel chair | 0.8 |
STAIRWAY HANDLING CAPACITY
Stairway construction details such as riser height of 100mm to 180 mm and treads of 280mm to 360mm, and an inclination from 15o to 33o has been considered
Cs = 0.83.v.D.Ws
Where:
Cs = stairway handling capacity (persons per minute)
v = Average pedestrian speed on slope (meters / second)
D = Average pedestrian density (persons per m2)
Ws = Effective Stairway width (meters)
STAIRWAY PEDESTRIAN FLOW
Pedestrian speed and flow for stated pedestrian density
Type of Traffic | Free Flow Design density (o.6 person per m2) | Full Flow Design density (2.0 person per m2) | ||||
Speed (m/s) | Flow rate (Person/Min) | Flow rate (Person/h) | Speed (m/s) | Flow rate (Person/Min) | Flow rate (Person/h) | |
Young/middle Aged men | 0.9 | 27 | 1620 | 0.6 | 60 | 3600 |
Young/middle Aged Women | 0.7 | 21 | 1260 | 0.6 | 60 | 3600 |
Elderly people Family groups | o.5 | 15 | 900 | 0.4 | 40 | 2400 |
HANDLING CAPACITY OF ESCALATORS
Escalator provides Mechanical means of continuously moving pedestrians from one level to another. A number of factors effect the handling capacity
1. Speed
2. Step width (hip width)
3. Inclination
4. Boarding and alighting areas
The theoretical handling capacity of a Escalator is given by
Ce = 60.V.k.s
Where:
Ce = Escalator handling capacity (persons per minute)
V = Speed along the incline (meters per second)
k = Average density of people(persons per m2)
s = Number of Escalator steps per meter
HANDLING CAPACITY OF LIFTS
The recommended design density when sizing a lift car can be smaller. A uniform occupancy figure is taken as 0.21 m2 per person. Lifts cannot handle the traffic volumes handled by other facilities, and has a considerable throttling effect on pedestrian movement
The t handling capacity of a Lift is given
Cl = 3600.P/INT
Where:
Cl = Lift handling capacity (passengers / hour)
P = Number of passengers in the car
INT = Interval between lift arrivals at the main floor(s)
Passenger Design Occupancy in lits
The table below indicates the maximum number of passengers that can be accommodated in commonly used car size assuming an occupancy density of 4.8 persons per m2
Rated Capacity (Persons) | Rated Load (Kg) | maximum Area (m2) | Occupancy( persons) |
6 | 480 | 1.30 | 6.2 |
8 | 630 | 1.66 | 7.9 |
10 | 800 | 2.00 | 9.5 |
13 | 1000 | 2.40 | 11.4 |
16 | 1250 | 2.90 | 13.8 |
21 | 1600 | 3.56 | 16.9 |
26 | 2000 | 4.20 | 20.0 |
33 | 2500 | 5.00 | 23.8 |
Escalator Arrangements
1.0 Successive Escalators with one intermediate Exit
Here the escalators have an exit to one side into a floor landing allowing the passengers to leave the first escalator and others to join the second escalator The flow landing can be considered as of the exit area provided it is also unrestricted. If it provides an area of 12 m2 then a 4m inter escalator spacing would be suitable
2.0 Successive Escalators with Two intermediate Exit
Here the escalators have an exit on each side into a floor landing allowing passengers to leave the first escalator and others to join the second escalator. The floor landing can be considered part of the exit area, provided it is unrestricted. as in the earlier case a 4.9m landing depth might be suitable. However if there is a possibility of one person and it is most likely to use the escalator landing to cross from one side of the escalator to the other extra circulation space of 1.0 m wide (shaded area) should be provided. In this case the escalator spacing should be 5.0 m
3.0 Pair of Successive Escalators side by with one intermediate Exit
Here the escalators serve in both directions and provides all passengers leaving the first escalator joined the second escalator the situation would be similar to 3. Here the possibility of conflict is very great and separation of 5.0m is essential
4.0 Pair of Successive Escalators side by with one two Exit
As in the earlier case the passengers will leave the first escalator and join the second and others will leave at the floor landing. Pedestrians from either pair can thus cross into other pairs reserved space, thus increasing the possibility of conflict and thus the inter escalator spacing of 5.0m is essential. To arrest the conflict situation additional circulation space of 1.0m non shaded area would be provided.
Passenger conveyers
Passenger conveyers do not present as many problems as escalators as they are horizontal(Moving Walkways) or ramped (moving ramps).They are often wider ie. 1400mm. Usually the spacing will be considerable and more than that suggested for escalators as they are often used to move people along rather than upwards.
Example Bulk transit system
With bulk transit systems large number of passengers arrive simultaneously. To handle such a situation it is necessary to spread the load by introducing something for the passengers to do before they reach the mechanical handling equipment. A good technique is to make them walk a reasonable distance. If possible some sale points should be introduced along the platform to further delay the arrival of passengers to the escalators.
THE PRINCIPLES OF LIFT DESIGN
1.0 The Need For Lifts
Lifts are installed into buildings to satisfy the vertical transportation needs of their occupants and visitors. They are necessary to provide a comfortable means of transportation to the different levels of the building. In some countries some of this requirement are written into statutory requirements.
2.0 Human Constraints
The lift system has to be acceptable to the travelling public
The most important requirement the public demands is the safety. This very important o that the passenger will feel confident about the way they are handled. But the passengers are human and are subject to constrains which fall into two categories; physiological and psychological, the body and the mind
2.1.1 Physiological constraints
The effects of the movement of the body limits the manner in which a passenger may be moved in a vertical plane. The human body is uncomfortable if its internal organs are caused to move within the body frame. This occurs when the body is subjected to acceleration and deceleration and the magnitude of the effect is depends on the age, physical and mental health and also whether he is prepared to experience a sudden movement.
Note that there is no limit to the velocity at which the passenger may traveling an enclosed lift car, as speed is not noticeable to the passenger. But the value of acceleration/deceleration (rate of change of velocity) should be limited to about one eighth of g or 1.5 m/s2 and the value of jerk ( rate of change of acceleration) to 2.0 m/s2
The effect of the acceleration of 1/8 g on a body weighing 80 kg in an upward direction is that it then weighs 90 kg. Likewise the same body subjected to a deceleration, while traveling in an upward direction would weigh 70 kg.
(a) Acceleration profile, note maximum 1.5 m/s2
(b) Velocity profile: note maximum speed 1.5 m/s
(c) Distance travelled; note total distance 3.0 m
It is the jerk value sometimes called shock which causes the most discomfort. If the value of the jerk exceeds 2.0 m/s2 for any length of time, even tenth of a second, discomfort will be experienced. Where as the velocity and acceleration/deceleration profiles be specified and controlled in drive systems, jerk cannot. Constant values of jerk requires that acceleration/deceleration profiles increase/decrease at a constant rate, and this is not always possible.
2.1.2 Psychological constraints
A passenger expects a good service from a lift system. But an individual passenger expects different grade of service at different times and locations. This can be categorized as the passenger’s waiting time constraint. In generally the average waiting time in an office blocks should not exceed 30 sec and in an residential block it should not exceed 60 sec. Waiting time is the prime psychological constraint.
TRAFFIC PLANNING AND SELECTION OF LIFTS
The figure -1 illustrates possible traffic pattern in an office building. It shows the number of up landing calls and down landing calls registered during the working day.
Start of the day there are a larger than average number of calls. These are due to building occupants arriving to start work, and are known as morning up peak.
Similarly, later in the day large down landing calls will be there, due to workers leaving the building and is called the evening down peak
ESTIMATION OF POPULATION
Lettable Area = 90 – 95% of gross area
Usable Area = 70 – 75% of gross area
Building Type | Estimated Population | |
Hotel | 1.5 - 1.9 persons/room | |
Flats | 1.5 - 1.9 persons/bed room | |
Hospital | 3.0 persons/bed space | |
School | 0.8 - 1.2 m2 net area/pupil | |
Office(Multiple Tenancy) | ||
Regular | 10 - 12 m2 net area/person | |
Prestige | 15 - 18 m2 net area/person | |
Office(Single Tenancy) | ||
Regular | 8 - 10 m2 net area/person | |
Prestige | 12 - 20 m2 net area/person |
ESTIMATION OF ARRIVAL TIME
The following table gives guidance for a variety of buildings based on surveys and experience of the population to be accommodated.
Building Type | Arrival rate | Interval (s) |
Hotel | 10 - 15 % | 30 - 50 |
Flats | 5 - 7 % | 40 - 90 |
Hospital | 8 - 10 % | 30 - 50 |
School | 15 - 25 % | 30 - 50 |
Office(Multiple Tenancy) | ||
Regular | 11 - 15 % | 25 - 30 |
Prestige | 15 - 17 % | 20 - 25 |
Office(Single Tenancy) | ||
Regular | 15% | 25 - 30 |
Prestige | 15 - 17 % | 20 - 25 |
PROBABLE QUALITY OF SERVICE IN OFFICE BUILDINGS
Actual average passenger waiting times would be the best indicator of the quality of service.
Interval (s) | Quality of |
Service | |
≤ 20 | Excellent |
25 | Very Good |
30 | Good |
40 | Poor |
≥ 50 | Unsatisfactory |
Following is a useful rule of thumb for the general level of service provided by a single lift serving several floors.
· Excellent service one lift for 3 floors
· Average service one lift for 4 floors
· Poor service one lift for 5 floors
Calculation of up peak performance
The up peak traffic pattern characterized by passengers arriving at the min terminal for transportation to upper floors. The lift system usually arranged to bring all cars successively to the main terminal to load the passengers and take them to their destination.
Calculation method
1. Round trip around the building; the round trip time (RTT)
2. A suitable number of lifts are then selected to provide a
Suitable up peak interval (UPPINT)
3. Up peak handling capacity (UPPHC)
RTT = 2Htv + (S+1)ts + 2Ptp
RTT - round trip time ( s)
H - average highest call reversal floor
S - average number of stops
P - average number of passengers carried
tv - time to transit two adjacent floors at contract(rated)
speeds (s)
ts - time consumed when making a sop (s)
tp - average passenger transfer time (entry or exit0 (s)
Calculation of up peak interval
In an installation of one car the RTT is equal to the up peak interval (UPPINT). For a system with L number of cars, the up peak interval is given by the following equation
UPPINT = RTT
L
UPPINT - UP PEAK INTERVAL (s)
RTT - ROUND TRIP TIME (S)
L - NUMBER OF CARS
Calculation of the Up Peak Handling Capacity
UPPHC is defined as the number of persons that can be transported from the main terminal to the upper floors of the building during the worst five minutes (300 sec.) of the Up Peak activity
UPPHC = (300 XP)
UPPINT
From the earlier equation
UPPINT = RTT
L
Therefore UPPHC = (300 XPxL)
RTT
UPPHC - UP PEAK HANDLING CAPACITY
UPPINT - UP PEAK INTERVAL (s)
RTT - ROUND TRIP TIME (S)
L - NUMBER OF CARS
Calculation of Average Number of Persons
P = 0.8 X Cc
Cc = Rated Capacity of the Car
Typical Lift Dynamics | |||
Lift Travel (m) | Rated Speed (m/S) | Accelration (m/s2) | Single Floor Flight Time (s) |
< 20 | <1.00 | 0.4 | 10.0 |
20 | 1.00 | o.4 - 0.7 | 7.9 |
32 | 1.60 | 0.7 - 0.8 | 6.0 |
50 | 2.50 | 1.0 | 5.5 |
63 | 3.00 | 1.2 | 5.0 |
100 | 5.00 | 1.2 | 4.5 |
120 | 6.00 | 1.2 | 4.5 |
>120 | > 6.00 | 1.2 | 4.5 |
Typical door closing & opening times | ||||||
Door Type | Closing and Opening times (s) for stated Door Width (m) | |||||
Closing | Opening (normal) | Opening (advanced) | ||||
0.8 | 1.1 | 0.8 | 1.1 | 0.8 | 1.1 | |
Side | 3.0 | 4.0 | 2.5 | 3.0 | 1.0 | 1.5 |
Center | 2.0 | 3.0 | 2.0 | 2.5 | 0.5 | 0.8 |
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