1. Building Construction 11
Dr Nabil El-Sawalhi
Associate professor
Engineering Projects Management

2. Stairs and Ramps
For access between floors and different levels in buildings a ladder, stair or ramp is used.
Lifts and escalators are also used for vertical circulation
Ladders
A ladder is made as a series of narrow horizontal steps (rungs), fixed between two uprights of wood or metal, on which a person usually ascends (climbs up) or descends (climbs down) facing the ladder.
A ladder may be fixed in an upright, vertical position or more usually at a slight angle to the vertical for ease of use

4. Stairs
A stair, or stairway, is the name given to a set of steps formed or constructed to make it possible to pass to another level on foot by putting one foot after the other on alternate steps to climb up or down the stair.
A stair may be formed as a series of steps rising in one direction between floors as a straight flight of steps.
More usually, a stair is formed as two or more straight flights of steps arranged to make a quarter or half turn at intermediate landings between floors.

5. Ramps
A ramp is a surface, sloping uniformly as an inclined plane, linking different levels. A ramp is formed or constructed at a slope of at least 1 in 20
The advantage of a ramp is that it allows relatively easy and safe access for wheelchairs and pushchairs and may be less daunting than a staircase to people with reduced mobility.

7. Functional requirements
The primary functional requirement of a stair or ramp is:
❑ To allow vertical movement, safely, from one level to another
Additional functions and performance requirements include:
❑ Strength and stability
❑ Ease of use
❑ Fire safety
❑ Control of impact sound
❑ Safety in use
❑ Avoiding traps
❑ Durability
❑ Aesthetics

8. Terms and definitions Flight
an uninterrupted series of steps between floors or between floor and landing, or between landing and landing.
A flight should have no more than 16 risers.
Small changes in height are not always obvious to users
single steps should not be used because they represent a trip hazard.
The rise and going of each step in one flight and in flights and landings between floors should be consistent.
Variations in the rise of steps will interrupt the user’s rhythm and might cause the user to trip and fall.

9. Treads and risers
The horizontal surface of a step is described as the tread, and the vertical or near vertical face as the riser.
the minimum and maximum rise and going varying depending on use:
❑ Private stair (in a domestic dwelling) would have a pitch range between 150 mm and 220 mm, with a going dimension between 220 mm and 300 mm.
❑ Utility stair. This also has a minimum rise of 150 mm, but a shallower maximum rise of 190 mm to accommodate heavier use.
The goings are larger compared to a private stair to facilitate ease of use, with a minimum of 250 mm to a maximum of 400 mm.

12. General access stair
As the use becomes more varied the maximum rise is reduced, with a minimum rise of 150 mm and a maximum of 170 mm. The going is the same range as the utility stair, from 250 mm to 400 mm.

13. Pitch To set out a stair, it is necessary to select a suitable rise and adjust it, if necessary, to the height from floor to floor so that the rise of each step is the same, floor to floor, and then either select a suitable going or use the formula
2Rises + 1Going = between 60 and 62.5 cm, to determine the going.

14. Headroom
For people and for moving goods and furniture, a minimum headroom of 2 m, measured vertically, is recommended between the pitch line of the stair and the underside of the stairs, landings and floors above the stair as illustrated in Figure 9.6.
Handrails
The general requirement for handrails is that there should be at least one handrail on a stairway. If the stairway is greater than 1 m, two handrails are required.
The height of the handrails should be between 900 and 1 m. Where the stair acts as a gangway greater than 1.8 m wide, a handrail should be used to divide the stairway (Figure 9.7 and Figure 9.8).

17. تشييد مباني 10

20. Landings
The position and general arrangement of landings to stairs are illustrated in Figure 9.10, Figure 9.11 and Figure 9.12.
The maximum number of risers in any flight is 16 (12 for disabled use), after which a landing must be provided.
The landing provides a position for the stair user to rest, if necessary, before continuing up or down the stairs

24. Types of stair
The three basic ways in which stairs with parallel treads are planned are illustrated in Figure These are a straight-flight stair, a quarter-turn stair and a half-turn stair.
Straight-flight stair
A straight-flight stair rises from floor to floor in one direction with or without an intermediate landing, hence the name. It is usually the most economical use of a stair.

25. تشييد مباني 10

26. تشييد مباني 10

28. Quarter-turn stair
A quarter-turn stair rises to a landing between two floors, turns through 90° and then rises to the floor above, hence ‘quarter turn’. The quarter-turn landing is sometimes replaced with winders for further economy in the use of space.
Half-turn or dog-leg stair
A half-turn stair rises to a landing between floors, turns through 180° and then rises parallel to the lower flight to the floor above, hence ‘half turn’. The landing is described as a half-space or half-turn landing

29. Stair well
Stairs are sometimes described as ‘open-well stairs’. The description refers to a space or well between flights. A half-turn or dog-leg stair can be arranged with no space between the flights or with a space or well between them, and this arrangement is sometimes described as an open-well stair. A quarter-turn stair can also be arranged with a space or well between the flights

30. Geometrical stairs
Geometrical stairs are constructed with treads that are tapered on plan, with the tapered treads around a centre support as a spiral (helical) stair, an open-well circular stair or as an ellipse on part of an ellipse on plan, as illustrated in Figure 9.14

32. STAIR LAYOUT AND STAIR PLAN
I n preparing a stair layout, we first determine the floor-to-floor height and then calculate the number of risers and treads. Assume that the floor-to-floor height in a building is 3.2m.
Assume further that we would like the riser height to be approximately 15cm. Dividing 320 by 15 gives us the number of risers:
Number of risers = 320/ 15 = 31.3
Because the number of risers must be a whole number, assume 21 risers. Dividing 320cm. by 21 gives the exact riser height, From the tread-riser relationship given earlier, the tread width is (or 62) - 2(15.2) = 29.5 to 32cm. We will use a tread width of 30cm. Assume further that a U-shaped stair is desired and the width of the stair is 120cm. By code, the minimum width of the landing must be the same

33. Example
The stair well internal Dim 5.4x2.6m
The height of floor 4.2 m

34. خطوات التصمیم:
Asume the hight of the riser (15-19cm) .let take it 16cm
Number of risers
n = (420/16) = => 26
Take round figure 26
Adjust the hight of floor or the hieght of the riser
تشييد مباني 10

35. Adjested hieght of floor H = 16 * 26 = 416 Cm.Or,
Adjusted hieght of riser
R = (420 / 26) = Cm.
تشييد مباني 10

36. 5. تقسیم الدرجات على الشواحط یجب أن یحقق أمرین رئیسیین، الأول ھو الوصول بالمستخدم إلى النقطة المراد الوصول إلیھا، والثاني التحقق من وجود مسافات كافیة بین البسطات، فمثلاً:
اقتراح 13 درجة لكل شاحط بدءاً من مدخل بئر الدرج قد یحقق مسافة كافیة بین البسطات وخاصةً أنه یجعل البسطة الأولى في الطرف المقابل للمدخل، وبالتالي تزداد المسافة الرأسیة بین المدخل والبسطة التالیة، وھو أمر مفضل، إلا أن ھذا النظام لا یوصل المستخدم للنقطة المطلوبة (المخرج) !!
تشييد مباني 10

37. اقتراح ترك ممر من المدخل حتى الجانب المقابل من بئر الدرج ثم بدء الصعود على الدرج ب 13 درجة لكل شاحط، وھذا الاقتراح یمكن أن یوصل المستخدم للنقطة المطلوبة، إلا أنه یجعل المسافة الرأسیة بین البسطة الأولى والمدخل صغیرة جداً.
6. بعد فشل محاولة التفكیر بشاحطین یمكن تجربة ثلاثة شواحط، ویمكن تقسیمھا (على سبیل المثال لا الحصر كما يلى: أ)
ب) 8- 9 – 9
ج) – 10
د) – 8
ه) – 12
تشييد مباني 10

38. مناقشة الخیارات:
كل الخیارات السابقة تحقق شرط الوصول إلى النقطة المطلوبة، وبالتالي یتم التركیز على قضیة المسافة بین البسطتین، وأمور أخرى.
من ناحیة المسافة بین البسطتین، فإن أصغر مسافة تتواجد في الخیار الأخیر (12+2) اى 14 درجة بین البسطتین وبالتالي فإن الارتفاع 16*14 = 224 وباستبعاد 14 سم تقريبا هي سمك البلاطة، تصبح المسافة الصافیة بین البسطتین 210 سم وھي اصغر مسافة مسموح
بھا بین بسطتین، بمعنى أن كل الخیارات الموجودة اجتازت ھذا الشرط. وبالتالي یكون القرار ھنا مبنیاً على نظرة أدق لوضع الدرج وظروفه، وبناءً على ذلك یتم اختیار أفضل الأفضل كما سیأتي.
تشييد مباني 10

39. بعد تقریر عدد الدرجات في كل شاحط ننتقل إلى خطوة اختیار طول الشاحط وعرض البسطات، ویفضل أن یكون عرض البسطات واحداً، وألا یقل عن عرض الشاحط بأي حال من الأحوال.
للحصول على طول الشاحط یجب معرفة عرض الدرجة N و من ثم التطبيق في العلاقة
L = N (n – 1)
حیث L هي طول الشاحط
ملاحظة: تم طرح 1 من عدد الدرجات في العلاقة الاخيرة لان الدرجة الاخيرة تعتبر ضمن البسطة . مما سبق دراستة نحصل على قسمة N للشاحط الثاني كمثال
تشييد مباني 10

40. 2R + N = 60 – 62, (Choose 62) 32 + N = 62 N = 30 Cm.
L = 30 (10 – 1) = 270 Cm.
تشييد مباني 10