Load analysis and structural consideration

Load Analysis and Structural Considerations (HSTU,Dinajpur).

1. Load and types. Structure after load analysis . Load transfer . - Core and load analysis. -Floorings and types. -Basement and parking CONTENT

2. Load is the external forces acting on very small area on a perpendicular point of a supporting structural element. LOAD

3. GEOPHISICAL SOURCES OF BUILDING LOADS : MAN MADE

4. TYPES OF LOAD:

5. DIFFERENT TYPES OF LOAD:

6. DEAD LOAD: (gravity/static load) Dead load consists of self weight of structure (beam, column, slab & struts etc.) & equipment permanently attached to structure such as furniture load, home accessories etc.

7. LIVE LOAD : Loads caused by contents of objects within or on a building are called occupancy loads. This loads includes allowance for the weights of people, furniture, moveable partitions, mechanical equipment etc.

8. CONSTRUCTION LOADS Structural members may be subjected to loads larger than designed loads during erection of a building these loads called construction loads The weight of floor forms and newly placed slab, which in total may equal twice the floor load.

9. TYPES AND EFFECTS OF TEMPERATURE LOAD : TYPES OF COLUMN EXPOSURE inside Flange at wall line Partial exposure Full exposure TYPES AND EFFECTS OF TEMPERATURE-INDUCED MOVEMENT : COLUMN BENDING : DIFFERENTIAL MOVEMENT BETWEEN INTERIOR AND EXTERIOR COLUMNS. column temperature may vary from -20 F to 120 F depending on the locality . expansion Cold air contraction Warm air

10. WIND LOAD : (dynamic/lateral load) The mean wind velocity is generally increases with height . Wind is essentially the l arge scale horizontal movement of free air. It plays an important role in design of tall structure because it exerts loads on building.

11. WIND DIRECTION : Th e multidirectional displacement may be less than It would have been if the same airflow had encountered the building on only one face.

12. WIND TURBULENCE:

13. Wind pressure: The wind pressure originates from two components previously defined : mean velocity and gust velocity. since static mean velocities are averaged over longer periods of time, the resulting wind pressure are also average pressure and exert a steady deflection on the building.

14. SEISMIC LOAD : (dynamic/lateral load ) It is this wave motion that is known as earthquake., It is apparent that a fault which has suffered from earthquakes in the past is most likely subject to future disturbances. When earthquakes occur, a buildings undergoes dynamic motion. This is because the building is subjected to inertia forces that act in opposite direction to the acceleration of earthquake excitations. These inertia forces, called seismic loads Earthquake is one of the destructive events in the world.

15. When earthquakes occur, a buildings undergoes dynamic motion .

16. Earthquake shaking is random

17. Ground shaking dur ing earthquakes

18. Result of earthquake

19. Load Transfer :

20. Different shapes of buildings considered in the present study Shape:

21. Circular Shape Rectangular Shape Square Shape Triang ular Shape

22. Lateral , horizontal and vertical load transfer LOAD TRANSFER IN STRUCTURE

23. Bracing: It is a device used as a supporting beam in a building that imparts rigidity and steadies the structure. It is extremely stiff. It helps positioning, supporting, strengthening or restraining the member of a structural frame. The basic principles are as follows: ·Vertical K-bracing maybe used along the columns · Horizontal portal bracing may be applied along the beams .

24. Braced Frame The effectiveness of the system, as characterized by a high ratio of stiffness to material quantity, is recognized for multistory building in the low to mid height range. Generally regarded as an exclusively steel system because the diagonal are inevitably subjected to tension for or to the other directions of lateral loading. Able to produce a laterally very stiff structure for a minimum of additional material, makes it an economical structural form for any height of buildings, up to the very tallest. Advantages: - Girders only participate minimally in the lateral bracing action Floor framing design is independent of its level in the structure Can be repetitive up the height of the building with obvious economy in design and fabrication. Disadvantages: Obstruct the internal planning and the locations of the windows and doors; for this reason, braced bent are usually incorporated internally along wall and partition lines, especially around elevator, stair, and service shaft. Diagonal connections are expensive to fabricate and erect

25. Type of High-Rise Structure Braced Frame Rigid Frame Structure Infilled Frame Structure Flat Plate and Flat Slab Structure Shear wall structure Coupled wall structure Wall-frame structure Framed tube structure The trussed tube Tube in tube or Hull core structure Bundled tube structure Core and Outrigger system Hybrid structure

26. Tubed mega frame Vertical tube mega column No central core That’s why all the load of the building re st on its perimeter

27. Load transfer in CCTV Tower China

28. Outrigger system central core with outriggers, connecting the core to the outer columns. the central contains either braced frame of shear wall. North east asia trade tower

29. Infilled Frame Structure Infilled serve also as external walls or internal partitions, the system is an economical way of stiffening and strengthening the structure. Consists of reinforce or steel column and girder frame with infills of brick work or concrete block works

30. Vertical displacement in infill frame structure :

31. Shear wall Concrete wall Punches are limited because of torsional and flexural rigidity In most cases lateral loads are carried by shear walls. Shear wall Gravity load and lateral load are ideally distributed. Also shear wall carries all lateral loads. Lateral load Gravity load

32. What is steel shear wall?

33. Diagrid system Here diagrid acts as a rigid shell and beam for support where rings are also used. lateral loads are introduced directly to the diagrid structure and immediately transferred into the triangulation system these loads are then handled in a similar manner to vertical Load paths are continuous and uninterrupted. Vertical gravity loads follow the structure of the tube from top to base along the diagonal members of said tube. Each diagonal can be viewed as continuous from top of tube to the bottom of the tube – this is one option for a load to follow to meet the ground Rings

34. Flat plate and flat slab structure flat plate is a two-way reinforced concrete framing system utilizing a slab of uniform thickness, the simplest of structural shapes flat slab is a two-way reinforced structural system that includes either drop panels or column capitals at columns to resist heavier loads and thus permit longer spans.  

35. Tube in tube structure: Bundle tube The inner and outer tube jointly resist the gravity and lateral loads . Bundle tube structure: This system easily resist the wind pressure and hold lateral loads. Tube in tube

36. Framed tube structure Gravity loads are distributed between the tubes and interior columns or walls Lateral loading acts at the perimeter.

37. STEPS OF FLOORING BASE-lay base coat of 100mm thick in the ratio of cement concrete 1:8:16 ( 1 part of cement,8 parts of fine sand & 16 parts of brick blast) or 1:4:8 on compaced earth under the floor. The base is same for all types of floors. FINISHING: then finishing of the floor is carried on, for different flooring materials. As we will discuss here the finishing of terrazzo,brick,stone & cement concrete floor

38. -Hard flooring -Sub flooring TYPES OF FLOORING Hard flooring Hard flooring (not to be confused  with (  "hardwood") is a family  of flooring  materials that includes concrete or  cement , ceramic  tile,glass tiles, and natural stone products.

39. Sub flooring The floor under the flooring is called the subfloor ,  which provides the support for the  flooring. Special   purpose subfloors  like floating floors, raised floors or sprung  floors  may  be  laid upon another underlying subfloor p rovides  the structural strength. Subfloors that are below grade  ( underground) or ground level  floors  in buildings

40. Basement and parking Generally b asements are common in tall buildings as carparks , storage of servicesand underground shopping centres . The Basement Parking space type refers to parking located below grade within an occupied building. The main purpose of constructing basements are : ( a )  to provide additional space , ( b )  as a form of buoyancy raft , ( c )  in some cases, basements may be needed for reducing net bearing  pressure by the removal of the soil. (d)  safe and efficient passage of automobiles as well as visitors to and from their vehicles Buoyancy raft

41. Function and attributes of basement Additional Structural Requirements : Below grade extension of the building structure to accommodate basement parking is required. This involves additional excavation, structural frame, floor slabs above, sloped vehicle access ramps, and basement perimeter walls and partitions separating parking from other building enclosed areas. Typical structural floor construction is 4000 PSI 6" concrete slab with welded wire fabric designed for a live load of 80 LBS/SF, and with a ramp slope of no more than 5.5%.

42. Importancs of basement

43. CORE: The core of a multistory building that integrates functions and service needs for established occupants. Such areas are normally composed of toilet facilities, elevator banks, janitors’ closet, utilities, mechanical facilities, smoke shafts and stair. 25% - 30% of the total circulation area. Core also known as facade envelope is a spatial element for load-bearing high-rise building system • Vertical circulation • Configuration • Floor-plate design • Function of Service Core • Service core types & placement • Service Core & Building Economy • Elevator design & configuration • Population density • Traffic analysis • Quality of ride • Service-core layout & space requirements Core wall

44. There are two principles of core design arrangement . the first is providing effective and conveninet vertical transportation system. The second is creating intact , flexible and consistently high quality space that can be occupied which can be adapted into the structural system. Shanghai tower design. Shenzhen pingan financial center

45. INTERIOR STRUCTURES EXTERIOR STRUCTURES

46. Vertical Circulation • Cores = service cores = risers • Contains : – Elevator shafts. – Elevator lobbies. – Main & escape stairways, ramp. – Riser-ducts. – Toilets. – Other service rooms. • Elevators = MAIN vertical circulation system. Configuration At initial design stage, designer DETERMINES: • Buildable net rentable areas (NRA) • Gross floor areas (GFA) • Typical & atypical floor-plates • Prepare a diagram + propose elevator configuration: • No. of banks • No. of stops • Transfer floor(s)

47. Function of Service Core Simply state that service is defined as those part of a building that consists of the service lift, fire stair , Toilet, service riser duct . Element of Service : TOILET FIRE STAIR. SERVICE/FIRE ELEVATOR RISER DUCT 1 . TOILET 2. PLUMBING 3. DUCTING 4. SERVICE/FIRE LIFT 5. FIRE STAIR

48. Structure of Core If the building structure been R.C.C , the core structure should be shear wall. In this case core structure may not be steel structure. If the building structure been steel , the core structure should be steel structure. In this case core structure may be R.C.C structure. If the building structure been Composite ,the core structure should be shear wall. In this case core structure may not be steel structure

49. diagonal connection vertical connection

50. Typology of core central core Split core End core Atrium core configuration plan Single tenant Double tenant Multiple tenant

51. Core design Service Core & Building Economy • Minimization of material costs • Optimization of core geometry • Minimization of core area • Minimization of construction time

52. POSITION OF CORE: should be located on the east & west side of the building. With both cores on hot sides, they provide Buffer zone. should be on the periphery of the usable floor space. Because-- Mechanical lighting Mechanical ventilation cvvcv Cantilevered system Slabs are supported by the core individually. Suspended system cvvcv slabs are suspended at the top of the core, so loads of all floor act from the top of the core.

53. central core : LOAD TRANSFER core

54. Spilt core : core core

55. Off center core : core

56. Service-core layout & space requirements :

57. Benefits of a peripheral core position: • No fire-fighting pressurization duct is needed • Good view out • Natural ventilation • Natural sunlight • A safer building in the event of total power failure • Solar-buffers & energy savings Service-core layout & space requirements : • Elevator car sizes & shapes • Elevator door types & sizes - common widths 1.1 m or 1.2m • Elevator shafts - are according to car shapes & sizes, and door sizes. Sufficient air around cars & counterweights should be provided to minimize buffeting & air-borne noise during operation. • Elevator core & lobby planning - ‘outward facing’ elevators VS ‘inward facing’ elevators.

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