Sunita Limbu 15 Design Report

ORIGINAL

Structural Analysis and Design Report of the Residential Building of Mrs. Sunita Limbu

Submitted by: Home Plans Consultancy (P.) Ltd. Dharan-12, Tel: 527270,

4 April 2017

Table of Contents 1.

BACKGROUND .......................................................................................................3

ASSUMPTIONS ..........................................................................................................................3 1.1 DESCRIPTIONS OF THE BUILDING ..........................................................................4 2.

NUMERICAL MODEL ............................................................................................5

2.1 MODELING .........................................................................................................................5 2.2 ANALYSIS ...........................................................................................................................8 2.3 DESIGN ............................................................................................................................10 3.

SUMMARY ...........................................................................................................12

4.

REFERENCES .......................................................................................................13

Summary This report comprises the summary of the structure design of residential building of Mrs. Sunita Limbu, ward no.-15, Dharan Sub-Metropolitan. The Report consists of design procedures adopted, assumptions made, the inputs made in the design. During design it is assumed that the construction will be supervised by a professional engineer. The designer will not be responsible if any alteration or changes to the structural system is made by the client or contractor without the prior written permission from the designer, or the alternations to the non-structural system is made such that the weight of each individual floor or the weight of the whole building is altered by more than 10% of design weight of each floor and the total weight. The design calculations and derivations are limited to only a minimum to let the concerned people know the methodology adopted. However, the calculations may be provided to the client or concerned authorities when needed, upon request. The building is newly designed conforming to 1994 Nepal National Building code, and expects underlying intent of Life Safety performance under design earthquake.

……………………. Mr. Sudeep K.C., M.Sc. in Structural Engineering NEC No. 5691 Civil “A” Category

Structural Analysis and Design Report of the Residential Building of Mrs. Sunita Limbu, ward no.-15

1. Background This report summarizes the structural analysis and design of building of Mrs. Sunita Limbu, ward no.-15. It has planned to utilize the building as a residential purpose except 2 rooms in ground floor which is for commercial purpose. The structural analysis in this building considers G+2 story with staircase cover (one floor for future extension). The aim of design is the achievement of an acceptable probability that structures being designed will perform satisfactorily during their intended life. With an appropriate degree of safety, they should sustain all the loads and deformations of normal construction and use and have adequate durability and adequate resistance to the effects of misuse and fire. Structural Analysis of the concerned building has been done in details with analysis and designs. The analysis and design has been based on the prevailing codes that are in practice in Nepal, the National Building code of Nepal (105:1994) and the IS code at places if required. This report consists of the design procedures adopted, the assumptions made, the inputs made in the design and the design output. Assumptions The following assumptions are taken into consideration in the seismic resistant analysis and design of structures: Adequate supervision and quality systems are provided during execution of the works. Construction is carried out by personnel having the appropriate skill and experience. Construction materials and products confirm to the pertinent codes and specifications. The structure is adequately maintained. The structure is used in accordance with the design brief. An earthquake is not likely to occur simultaneously with maximum flood, wind, waves or tides. Resonance as visualized under steady state sinusoidal excitation will not occur, as the small duration of earthquake is not enough to build up resonance amplitudes. Subsoil does not considerably settle or slide due to earthquake at the site of structure. This report is divided into three chapters. Chapter one begins with introductions and general description Chapter two comprises the numerical modeling, analysis and design; Chapter three presents the summary and recommendations

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Structural Analysis and Design Report of the Residential Building of Mrs. Sunita Limbu, ward no.-15

1.1 Descriptions of the building Following are the descriptions of the building based on architectural drawing study.

Figure: Typical Architectural Floor Plan Table 1: General description Building Owner

Mrs. Sunita Limbu

Location

ward no.-15,Dharan Sub-Metropolitan, Sunasari

Terrain type

Plain

Nos. of Blocks

One

Type of structure

Reinforced concrete frame building

No of stories

Three (one for future extension)

Plan configuration

Regular

West (Front) View

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Structural Analysis and Design Report of the Residential Building of Mrs. Sunita Limbu, ward no.-15

Vertical configuration

Regular

Position of the building block

Erected coinciding along property line at South side

Building dimension

Refer attached drawing

Storey height

10’ 0” all floors

Total Plinth Area

770.50 sq ft

Foundation, Column, Beam, Slab etc.,

Refer to table 2, Under the heading Member Properties

2. Numerical Model 2.1 Modeling The analysis has been carried out with the most popular and reliable structural analysis software “ETABS 2016”. All the models are built up in 3-Dimensions and actual 3-D analysis is performed ETABS 2016 is based on Finite Element Method. Modulus of elasticity and poison’s ratio for the materials used are taken accordingly. Beams and columns are modeled as frame (line) elements with sufficient and appropriate meshing. The section properties used are based on preliminary section sizing with consideration for deflection, minimum sizing specified and serviceability. The buildings are modeled as a series of load resisting elements. The lateral loads to be applied on the buildings are based on the Nepal National Building Code. The study is performed for seismic region Dharanu (z = 1) as per NBC 105: 1994. The building sadopted consist fo reinforced concrete and brick masonry elements. The frames are assumed to be firmly fixed at the bottom and the soil-structure interaction is neglected. Table : Model data of the buildings Structure

SMRF

Number of stories

G+2 and staircase cover

Type of building use

Residential

Seismic gap

N/A

Foundation type

Strap and Isolated

Seismic zone

Dharan

Material Properties Young’s modulus of M20 concrete, E

22.36x 105 KN/m2

Grade fo concrete

For all structural elements M20

Grade fo steel

Fe 500 for all

Density of reinforced concrete

25 KN/m3

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Structural Analysis and Design Report of the Residential Building of Mrs. Sunita Limbu, ward no.-15

19.0 KN/m3

Density of brick masonry Menber Properties Thickness of floor slab

130mm

Beam size

250mm x 350mm

Column size

350mm x 350mm

Thickness of wall

230mm and 115mm

Deaed Load Intensities 2 kN/m2

Floor finishes and other Live Load Intensities

3.0 kN/m2 , 2.0 kN/m2 , 1.50 kN/m2

Staircase-verandah, Rooms, Roof

The laod cases/Combinations considered in the seimic analysis are as per IS 1893- 2002. Earthquake LL on slab as per Cl. 10.2, NBC 105:1994

Base Shear Calculation as per NBC 105: 1994 Seismic zone Seismic Zone factor

Dharan Z

cl 8.1.6, fig 8.2

Type of Building Importance factor

1 All other

I

cl 8.1.7, table 8.1

1.0 Ductile Moment Resisting Frame

Structural performance factor

K

cl 8.1.8, table 8.2

1.0

Height of the building

h

12.192

Dimension of the building Along X

Dx

6.710

Dimension of the building Along Y Time period of the building along X,

Dy Tx= 0.09h/√Dx

Time period of the building along Y

Ty= 0.09h/√Dy

Lateral load resisting system

cl 7.3 cl 7.3

Soil type Cx

Basic seismic coefficient along Y Design Horizontal Seismic Coefficient along X

Cy

Seismic Wt of the Building Base Shear

0.349 Sub Soil Type II

Basic seismic coefficient along X

Design Horizontal Seismic Coefficient along Y

9.910 0.424

cl 8.1.4, fig 8.1 cl 8.1.4, fig 8.1

0.080

Cdx = CZIK

cl 8.1.1

0.080 0.080

Cdy = CZIK W

cl 8.1.1

0.080

VB

Page 6 of 19

2923.8537 Cl 7.5.3 Ah W

233.9083

Structural Analysis and Design Report of the Residential Building of Mrs. Sunita Limbu, ward no.-15

Load Combination as per NBC 105:1994, as bellows,

Fig: 3-D view of the building in ETABS 2016

Fig: 2-D (Plan) view of the building in ETABS 2016

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Structural Analysis and Design Report of the Residential Building of Mrs. Sunita Limbu, ward no.-15

Fig: 2-D (Elevation) view of the building in ETABS 2016

Fig: 2-D (Elevation) view of the building in ETABS 2016

2.2 Analysis Three dimensional Static Linear Analysis has been carried out using the standard software ETABS 2016.The structure is assumed to be fixed at the foundation level. The brick wall is considered as the filler wall only. The beams are modeled as rectangurlar beams. The flange effect of the beams has been neglected. Center to center dimension of the structure has been considered in the analysis. The rigid end effect has also been considered in the analysis. Following tables summarizes the analysis output of the modelled structure.

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Structural Analysis and Design Report of the Residential Building of Mrs. Sunita Limbu, ward no.-15

Table: Auto seismic –User coefficients Load Pattern

Type

Direction

Bottom Story

Top Story

C

K

Weight Used

Base Shear

kN

kN

EQ_X

Seismic

X

Story3

Base

0.08

1

2923.8537

233.9083

EQ_Y

Seismic

Y

Story3

Base

0.08

1

2923.8537

233.9083

Table: Model Load Participation ratio Item Type

Case

Static %

Item

Dynamic %

Modal

Acceleration

UX

98.53

86.4

Modal

Acceleration

UY

98.45

86.46

Modal

Acceleration

UZ

61.41

9.54

Table: Model Participating Mass Ratio Period Case

Mode

UX

UY

UZ

Sum UX

Sum UY

Sum UZ

sec Modal

1

0.715

0.85

0.00

0.00

0.85

0.00

0.00

Modal

2

0.696

0.00

0.77

0.00

0.86

0.77

0.00

Modal

3

0.633

0.00

0.09

0.00

0.86

0.86

0.00

Modal

4

0.305

0.00

0.00

0.00

0.86

0.86

0.00

Modal

5

0.304

0.00

0.00

0.02

0.86

0.86

0.02

Modal

6

0.301

0.00

0.00

0.01

0.86

0.86

0.04

Modal

7

0.268

0.00

0.00

0.00

0.86

0.86

0.04

Modal

8

0.268

0.00

0.00

0.02

0.86

0.86

0.06

Modal

9

0.265

0.00

0.00

0.01

0.86

0.86

0.07

Modal

10

0.253

0.00

0.00

0.00

0.86

0.86

0.07

Modal

11

0.253

0.00

0.00

0.02

0.86

0.86

0.09

Modal

12

0.25

0.00

0.00

0.01

0.86

0.86

0.10

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Structural Analysis and Design Report of the Residential Building of Mrs. Sunita Limbu, ward no.-15

2.3 Design The aim of structural design is the achievement of an acceptable probability that structures being design will perform satisfactorily during their intended life with an appropriate degree of safety, they should sustain all the loads and deformations of normal construction and use and have adequate durability and adequate resistance to the effect of misuse and fire. Therefore, Limit state method is used for the design of RCC elements. The design is based on IS: 456-2000, SP16, IS: 1893-2002, and Reinforced Concrete Designer’s Handbook are extensively used in the process of design. Foundation design is carried out to satisfy strength and stability requirements. The space frame is considered as a special moment resisting frame (SMRF) with a special detailing to provide ductile behavior at every joint between beams and columns and in other parts to get ductility and comply with the requirements given in IS 13920:1993, Hand book on Concrete Reinforcement and Detailing SP: 34 and NBC 201:1994. The provision of shear reinforcement is sufficient so that shear failure mode is avoided moreover there will be failure in flexure since this is more ductile. Hence the design philosophy of “Strong Column and weak beam”. Bearing capacity of the soil was assumed to be 150 kN/m2. Raft foundation is adopted. Durable M20 concrete has been used in the foundation which is in contact with the soil. Ductile detailing has been extensively adopted while detailing. The design out put has been presented in the form of structural drawing. 2.3.1 Summary of Design For all Floor Slab Provide the Thickness of the Slab = 130 mm Bottom Main bar in X-direction = 8 mm Ø @ 150 mm c /c Bottom Main bar in Y-direction= 8 mm Ø @ 150 mm c /c Top Main bar in X-direction = 8 mm Ø @ 150 mm c /c Top Main bar in Y-direction= 8 mm Ø @ 150 mm c /c Section of columns & Reinforcement Details S.N.

COLUMN SIZE

COLUMN NAME/Grids

Ground Floor & First floor

Remaining floor to roof

1

300mm X300mm

Column C-1

4#16mmØ + 4#12mmØ

8#12mmØ

(Remaining)

Ties 4 legged 8mmØ@ 100mm and 150 mm at centers (refer Structural Drawings)

Stirrups 2

300mm X300mm

Column C-2

8#16mmØ

4#16mmØ + 4#12mmØ

(B-1, B-2, B-3)

Ties 4 legged 8mmØ@ 100mm and 150 mm at centers (refer Structural Drawings)

Stirrups For all details, Refer submitted Structural Drawing

It is recommended that the mix design of concrete should be carried out to conform the desired strength as per IS 456-2000. Page 10 of 19

Structural Analysis and Design Report of the Residential Building of Mrs. Sunita Limbu, ward no.-15

Details of Floor Beams

Floor name

Size (BXD)

Grid

Top bar

Bottom bar

(mm) additional bars Foundation/Plinth beam

230x230

All

Ground Floor Beams and First floor 230X350 Beams

All

All

Roof Beams and Staircase cover

230X350

main bars

additional bars

main bars

3# 12mmØ

3# 12mmØ

1#12mmØ

2# 16mmØ

2# 16mmØ

1#12mmØ

2# 12mmØ

2# 12mmØ

Stirrups 2 legged, 8mmØ@ 100mm and 150 mm at centers (refer Structural Drawings) For all details, Refer submitted Structural Drawing It is recommended that the mix design of concrete should be carried out to conform the desired strength as per IS 456-2000. Summary of Details of Foundation

S.N. Foundation Symbol

d D Depth of LxXLy (mm) (mm) Foundation (mm) (mm)

Reinforcement

1.

A-1, A-2, A-3, A4, B-4, C-1, C-2, C-3, C-4

200

400

2000

1500x1500

12mmØ@150mm C/C both ways

2.

B-1, B-2, B-3

200

400

2000

1500X2000 12mmØ@150mm C/C both ways

Floor name

Size (BXD)

Grid

Top bar

Bottom bar

(mm) additional bars Strap Beams

300x400

Refer drawing

main bars 3#16mmØ

additional bars

main bars 3# 16mmØ

Stirrups 3 legged, 8mmØ@ 150mm at centers (refer Structural Drawings) Page 11 of 19

Structural Analysis and Design Report of the Residential Building of Mrs. Sunita Limbu, ward no.-15

3. Summary This report is outcome of structural analysis and design of the residential building of Mrs. Sunita Limbu, ward no.-15, Dharan Sub-Metropolitan. Three dimensional static linear analysis has been carried out using the standard software ETABS 2016. The design of the members has been done as per philosophy of limit state method. For the design of the members IS 456: 2000 and aid SP 16 has been extensively used. Ductile detailing has been extensively adopted while detailing. The design out put has been presented in the form of structural drawing. Building which are properly planned, designed and constructed has a good capacity to withstand earthquakes. Past earthquakes have shown that well designed buildings have withstood earthquakes well. Earthquake resistant design of the building costs money. The total cost of the building may be increase. The owners of the building should bear this in mind and be mentally prepared to invest this extra cost.

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Structural Analysis and Design Report of the Residential Building of Mrs. Sunita Limbu, ward no.-15

4. References IS : 456-200 : Code of Practice for Plain and Reinforced Concrete IS 875n(Parts 1-5) : Code of Practice for Design Loads (Other than Earthquake) for Buildings and Structures (second revision) o Part 1 – Dead Loads o Part 2 – Imposed Loads NBC 105 : 1994 : Seismic Design of Buildings in Nepal IS : 1893- 2002 : Criteria for Earthquake Resistant Design of Structures IS 13920 – 1993: Ductile Detailing of Reinforced Concrete Structures Subjected to Seismic Forces – Code of Practice SP: 16- 1980 : Design Aids for Reinforced Concrete to IS : 456-1978 SP : 34- 1987: Handbook on Concrete Reinforcement Detailing Jain, A.K. Reinforced Concrete, Limit State Design, fifth edition, Nem Chand and Bros, Roorkee,1999 Sinha, S.N. Reinforced Concrete Design, Second edition, Tata McGraw Hill Publishing Company Ltd, New Delhi, 1996 Pillai, U.C. and Menon,.D. Reinforced Concrete Design, Second edition, Tata McGraw Hill Publishing Company Ltd, New Delhi,2003.

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Structural Analysis and Design Report of the Residential Building of Mrs. Sunita Limbu, ward no.-15

Annex A: Typical Design ETABS 2016 Concrete Frame Design IS 456:2000 Column Section Design

Column Element Details Type: Ductile Frame (Summary) Level

Element

Unique Name

Section ID

Combo ID

Station Loc

Length (mm)

LLRF

Story1

C18

24

COL

DL+L1.3LL-1.25EX

0

3048

0.624

Section Properties b (mm)

h (mm)

dc (mm)

Cover (Torsion) (mm)

300

300

58

30

Material Properties Ec (MPa)

fck (MPa)

Lt.Wt Factor (Unitless)

fy (MPa)

fys (MPa)

22360.68

20

1

500

500

Design Code Parameters ɣC

ɣS

1.5

1.15

Axial Force and Biaxial Moment Design For Pu , Mu2 , Mu3 Design Pu kN

Design Mu2 kN-m

Design Mu3 kN-m

Minimum M2 kN-m

Minimum M3 kN-m

Rebar Area mm²

Rebar % %

438.8145

8.7763

-51.1988

8.7763

8.7763

1439

1.6

Axial Force and Biaxial Moment Factors K Factor Unitless

Length mm

Initial Moment kN-m

Additional Moment kN-m

Minimum Moment kN-m

Major Bend(M3)

0.68861

2698

-20.4795

0

8.7763

Minor Bend(M2)

0.681536

2698

-2.5929

0

8.7763

Shear Design for Vu2 , Vu3 Shear Vu kN

Shear Vc kN

Shear Vs kN

Shear Vp kN

Rebar Asv /s mm²/m

Major, Vu2

39.2919

67.29

29.0396

39.2919

332.53

Minor, Vu3

37.7918

67.29

29.0396

37.7918

332.53

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Structural Analysis and Design Report of the Residential Building of Mrs. Sunita Limbu, ward no.-15

Joint Shear Check/Design Joint Shear Force kN

Shear VTop kN

Shear Vu,Tot kN

Shear Vc kN

Joint Area cm²

Shear Ratio Unitless

Major Shear, Vu2

N/A

N/A

N/A

N/A

N/A

N/A

Minor Shear, Vu3

N/A

N/A

N/A

N/A

N/A

N/A

(1.1) Beam/Column Capacity Ratio Major Ratio

Minor Ratio

N/A

N/A

Additional Moment Reduction Factor k (IS 39.7.1.1) Ag cm²

Asc cm²

Puz kN

Pb kN

Pu kN

k Unitless

900

14.4

1349.7619

277.9229

438.8145

0.849892

Consider Ma

Length Factor

Section Depth (mm)

KL/Depth Ratio

KL/Depth Limit

KL/Depth Exceeded

Ma Moment (kN-m)

Major Bending (M3 )

No

0.885

300

6.193

12

No

0

Minor Bending (M2 )

No

0.885

300

6.129

12

No

0

Additional Moment (IS 39.7.1)

Notes: N/A: Not Applicable N/C: Not Calculated N/N: Not Needed

ETABS 2016 Concrete Frame Design IS 456:2000 Beam Section Design

Beam Element Details Type: Ductile Frame (Summary) Level

Element

Unique Name

Section ID

Combo ID

Station Loc

Length (mm)

LLRF

Story1

B39

14

BM

DL+L1.3LL-1.25EX

150

3200

1

Section Properties

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Structural Analysis and Design Report of the Residential Building of Mrs. Sunita Limbu, ward no.-15

b (mm)

h (mm)

bf (mm)

ds (mm)

dct (mm)

dcb (mm)

230

350

230

0

33

33

Material Properties Ec (MPa)

fck (MPa)

Lt.Wt Factor (Unitless)

fy (MPa)

fys (MPa)

22360.68

20

1

500

500

Design Code Parameters ɣC

ɣS

1.5

1.15

Factored Forces and Moments Factored Mu3 kN-m

Factored Tu kN-m

Factored Vu2 kN

Factored Pu kN

-53.5541

1.0211

52.3086

0.0266

Design Moments, Mu3 & Mt Factored Moment kN-m

Factored Mt kN-m

Positive Moment kN-m

Negative Moment kN-m

-53.5541

1.5147

0

-55.0688

Design Moment and Flexural Reinforcement for Moment, Mu3 & Tu Design -Moment kN-m Top

(+2 Axis)

Design +Moment kN-m

-Moment Rebar mm²

+Moment Rebar mm²

Minimum Rebar mm²

Required Rebar mm²

446

0

446

173

223

0

0

223

-55.0688

Bottom (-2 Axis)

0

Shear Force and Reinforcement for Shear, Vu2 & Tu Shear Ve kN

Shear Vc kN

Shear Vs kN

Shear Vp kN

Rebar Asv /s mm²/m

69.9136

37.5914

39.4254

46.3913

344.64

Torsion Force and Torsion Reinforcement for Torsion, Tu & VU2 Tu kN-m

Vu kN

Core b1 mm

Core d1 mm

Rebar Asvt /s mm²/m

1.0211

52.3086

184

304

241.31

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Structural Analysis and Design Report of the Residential Building of Mrs. Sunita Limbu, ward no.-15

Annex B: Software Design Out put

Figure showing rebars along grid 1-1, 2-2, ETABS 2016

Figure showing rebars along grid 3-3, 4-4, ETABS 2016

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Structural Analysis and Design Report of the Residential Building of Mrs. Sunita Limbu, ward no.-15

Figure showing rebars in beams at first floor level and second floor level, ETABS 2016

Figure showing rebars in beams at third floor level and stair cover level, ETABS 2016

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