A REPORT ON STRUCTURAL AN AL YSI S AND DES I GN OF RE SIDENTI AL BUI LDI NG
Prepared For MR. Maha rudra
Pr epar ed By NAME: NEC NO: LSMC NO:
Submi tted T o L alitpur Sub-me tropo li tan City Offi ce, L alitpur
05 December 2016
TO WHOM IT MAY CONCERN
This report comprises the summary of the structural design of Residential Building. The report consists of design procedures adopted, assumptions made, and the input assign in the design. During design it is assumed that the client will completely followed the architectural as well as the structural design. It is also assumed that the construction will be supervised by a professional engineer. The designer will not be responsible if any alteration or change to the structural system is made by the client or contractor without the prior permission from the designer, or the alteration 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 the design weight of the floor and the total weight. The design calculations and derivations are limited to only to let the concerned people know the methodology adopted. However, the calculation may be provided to the client or the concerned authorities when needed, upon request.
………………………………. NAME: NEC NO: LSMC NO:
(DESIGNER)
Page | i
Table of Contents 1
Introduction ....................................................................................................... 6
1.1
General ................................................................................................................ 6
1.2
Salient Features ................................................................................................... 6
1.2.1
Project Information ......................................................................................... 6
1.2.2
Building Features ............................................................................................ 6
1.2.3
Site Condition.................................................................................................. 8
2
Analysis Technology and Methodology .......................................................... 8
2.1
General ................................................................................................................ 8
2.2
Codes and Standard used .................................................................................. 10
2.3
Software Used ................................................................................................... 10
3
Analysis ............................................................................................................ 11
3.1
Material properties ............................................................................................ 11
3.1.1
Concrete ........................................................................................................ 11
3.1.2
Reinforcement Steel ...................................................................................... 11
3.2
Section Properties ............................................................................................. 12
3.3
Loadings............................................................................................................ 12
3.3.1 3.3.2 3.4
Load Cases .................................................................................................... 12 Load Combination ......................................................................................... 13 Estimation of Load............................................................................................ 14
3.4.1
Unit Weight (Dead Load).............................................................................. 14
3.4.2
Live Load ...................................................................................................... 18
3.4.3
Seismic Load ................................................................................................. 19
4
Analysis Output...............................................................................................20
4.1
Seismic Coefficient Method ............................................................................. 20
4.2
Story Drift ......................................................................................................... 21
4.3
Modal time period and mass participation ........................................................ 22
5
Force Diagram................................................................................................. 23
5.1.1
Axial Force Diagram ..................................................................................... 23
5.1.2
Shear Force Diagram ..................................................................................... 24
5.1.3
Moment Diagram .......................................................................................... 26
5.2
Joint Reactions .................................................................................................. 27
6
Design of Structural Members (Sample Design) .......................................... 27
6.1
Design Input and Output ................................................................................... 27
6.1.1
Section Input Diagram .................................................................................. 27 Page | ii
6.1.2
Design Output Diagram ................................................................................ 29
6.2
Design of Slab ................................................................................................... 32
6.3
Design of Beam................................................. Error! Bookmark not defined.
6.4
Design of Column ............................................. Error! Bookmark not defined.
6.5
Design of Footing (Isolated) ............................. Error! Bookmark not defined.
7
References ........................................................................................................ 51
Page | iii
List of Figure Figure 1: Ground floor Plan of Building ..................... Error! Bookmark not defined. Figure 2: X-Section of Building .................................... Error! Bookmark not defined. Figure 3: 3D-Model of Building ................................................................................ 10 Figure 4: Frame Load (Wall Load) on Grid E-E .................................................... 17 Figure 5: Area Load (LL) on Floor Slab ..................... Error! Bookmark not defined. Figure 6: Area Load (Floor Finishing Load) on Floor Slab................................... 18 Figure 7: Distribution of Story shear (EQx)................ Error! Bookmark not defined. Figure 8: Story displacement (EQx)......................................................................... 22 Figure 9: Story displacement (EQy)......................................................................... 22 Figure 10: Envelope - Axial Force diagram: Grid 2-2............................................ 23 Figure 11: Envelope-Shear Force diagram: Grid 2-2............................................. 25 Figure 12: Envelope -Moment diagram: Grid 2-2 ................................................. 26 Figure 13: Joint Level and Reactions....................................................................... 27 Figure 14: Section Input in Frame along Grid 2-2 ................................................. 28 Figure 15: Section Input in First Floor ........................ Error! Bookmark not defined. Figure 16: Design Output in Frame along Grid 2-2 ............................................... 30 Figure 17: Design Output in First Floor ...................... Error! Bookmark not defined.
Page | iv
List of Table Table 1: Load Cases ................................................................................................... 12 Table 2: Load Combination ...................................................................................... 13 Table 3: Unit Weight of Materials............................................................................ 14 Table 4: Dead Load Calculation ............................................................................... 15 Table 5: Mass Source for Seismic Load ...................................................................20 Table 6: Fundamental Time period.......................................................................... 20 Table 7: Seismic coefficient and base shear............................................................. 21 Table 8: Beam reinforcement details ........................... Error! Bookmark not defined. Table 9: Summary of Design of Column................................................................. 34 Table 10: Summary of Design of Footing ............................................................... 46
Page | v
1
Introduction
1.1
General
This report presents the structure analysis and design of Residential cum Commercial Building. The building is Special Reinforced Concrete Moment Resisting Frame (SMRF) type of building. It is designed to meet both strength and serviceability requirements when subjected to gravity and earthquake loads. The analysis and design has been based on IS codes that are in practice in Nepal. This report consists of the design assumptions, design methodology, design inputs and outputs, and sample design of structural members. 1.2 1.2.1
1.2.2
Salient Features Project Information
Type of building
:
Commercial building
Location
:
Plinth Area
:
1046.13 square ft.
Total Floor Area
:
4973.82 square ft.
Total land Area
:
Floor area Ratio (FAR)
:
1.75
Land Coverage (%)
:
70
Building Features
The building has some special features which are listed below: Type of Building
:
Special RC Moment Resisting Frame Structure
Shape
:
Regular Rectangular Shape
Plinth level
:
As per architectural drawing
Roof floor Type
:
Accessible, Terrace
Walls
:
Brick walls
Footing Type
:
Isolated & Combined as per as Design
Depth of
:
Minimum 5 ft below ground level or as per site Page | 6
foundation
condition
Dimension
:
42’-10” X 38’-6”
Story Height
:
9’-5” (center to center)
Total Height
:
19.81 m
No of Story
:
Ground floor +Three Story
Figure 1 Ground Floor of Building Plan
Page | 7
Figure2 X Section of Building 1.2.3
2 2.1
Site Condition
Type of soil
:
Type II, Soft Soil as per IS-1893(Part 1):2000
Allowable bearing pressure
: 120 KN/m (Assumed)
Seismic Zone Factor
: 0.36 as per IS-1893(Part 1):2000
2
Analysis Technology and Methodology General
After completion of Architectural design, the layout of columns and beams are done without affecting the Architectural functions of building so far. Structure is Page | 8
modeled using finite element method. A three-dimensional beam element having 12 DOF with 6 DOFs at each node were used for modeling beams and columns in the building, while 24DOFs shell element with 6 DOFs at each node were used to model slab wall. The structure is analyzed by the linear elastic theory to calculate internal actions produced by anticipated design loads. The analysis is carried out using state of art three dimensional structural analysis programs like ETABS 2015. The design loads considered as per the relevant codes of practice comprise dead load due to permanent structures, live load due to occupancy of the structure and seismic load due to anticipated earthquake possible at the proposed location. A number of load combinations are considered to obtain the maximum values of design stresses. Following considerations is made during modeling, analysis and design.
The structures are Special Reinforced Concrete Moment Resisting Frame (SMRF) type. Beams and columns are considered as the structural load resisting elements. Although non-structural components like wall plaster, infill walls, floor finishing etc has comes effects on structural performance, they are considered only as loading.
For all structural elements, M20 grade concrete are used.
Centre-line dimensions are followed for modeling, analysis and design.
Floor slabs are assumed to be rigid in their own plane. The slab action has been modeled by rigid floor diaphragms. Slabs are also considered in modeling. Slab is modeled as shell element.
Beam and columns are modeled as frame elements.
The main beams rest centrally on columns to avoid local eccentricity.
Foundation is assumed to be fully rigid at the plinth level.
The beam-column joint is not modeled in detail.
Preliminary sizes of structural components are assumed by experience.
Seismic loads were considered acting in the horizontal direction (along either of the two orthogonal directions of building) and not along the vertical direction, since it is not considered to be significant for design of structural members suitable load combinations as suggested by IS 1893– 2002 are used.
Page | 9
Figure 1: 3D-Model of Building
2.2
Codes and Standard used
For the structural analysis and design, the following codes and standard are followed:
2.3
IS 456- 2000 Code of practice for plain and reinforced concrete IS 875-1987 Code of practice for design loads (other than earthquake) for buildings and structures IS 1893-2002 Criteria for Earthquake Resistant Design of Structures, IS 13920-1993 Code of practice for ductile detailing of reinforced concrete structures subjected to seismic forces NBC Nepal Building Code
Software Used
The following software is used for the structural analysis and design. ETABS 2015
For analysis and design of the structures Page | 10
For structural modeling of the present building, ETABS software was used. ETABS is a special purpose finite element analysis and design program developed specifically for building systems. With ETABS, models are defined logically floor-by-floor, column-by-column, bay-by-bay and wall-by-wall and not as a stream of non-descript nodes and elements as in general purpose programs. The software has very powerful numerical methods, design procedures and international design codes, all working from a single comprehensive database. At its core, it utilizes the same analysis engine as used by SAP2000. Among others, ETABS can do model generation, seismic and wind load generation, finite element-based linear and non-linear static and dynamic analysis, concrete frame design (column and beam) and shear wall design.
3
Analysis
3.1 3.1.1
Material properties Concrete
Column is designed for M20 grade of concrete. And all other components of plain and reinforced concrete unless specified in design are M20 grade. Modulus of Elasticity [E c]
2
= 5000 √fck N/mm (Cl. 6.2.3.1, IS 456:2000) 2
= 22360 N/mm for M20 grade
Poisson’s Ratio [U] Unit Weight
= 0.2 3
= 25 KN/m
2
Characteristic Strength [ƒck] = 20 N/mm for M20 grade 2
= 25 N/mm for M25 grade The structural design strength is derived from the characteristic strength multiplied by a coefficient 0.67 and divided by the material partial safety factor. The partial factor for concrete in flexure and axial load is 1.5.
3.1.2
Reinforcement Steel
Characteristic strength of high yield steel is taken as 415 MPa for main rebar and 415 MPa shear rebar and material partial safety factor is to be 1.15. Modulus of Elasticity [E s]
5
= 2x10 N/mm
2
Page | 11
Ratio [U] Poisson’s 3.2
= 0.3
Section Properties
Preliminary Size of Members
The preliminary sizes of Beam, Column, and Slab were chosen based on experience. Tie beam
: 230mm*230mm
Beam
: 230 mm x 350 mm
Column
: 350 mm x 350 mm
Slab Thickness : 125 mm During the analysis, beam and column are modeled as frame elements whereas slabs are modeled as area element. 3.3
Loadings
The following considerations are made during the loading on the structural model:
3.3.1
The loads distributed over the area are imposed on the area element and the loads distributed over the length are imposed on the frame elements whenever possible. Where such loading is not possible, equivalent conversion to different loading distribution is carried to load the model near the real case as far as possible. For lateral load, necessary calculations are performed to comply with the requirements of IS 1893-2000.
Load Cases
The following load cases are used for the loading during analysis. Table 1: Load Cases
Page | 12
Load Name
Load Type
Description
Unit
Dead
Dead
Self-weight of the structure
KN/m
Wall
S. Dead
Wall Load
KN/m
Finish Partition
S. Dead
Floor Finish Load
S. Dead
LL Floor
Partition Wall Load
Live
Imposed Load
Remarks 2
On floor & roof beam
KN/m
2
KN/m
2
On floor slab
KN/m
2
On floor slab
KN/m
2
On terrace slab
On floor & roof slab
LL Terrace
Live
Imposed Load
EQX
Quake
Seismic Coefficient IS1893
X+0.05Y
EQY
Quake
Seismic Coefficient IS1893
Y+0.05X
3.3.2
Load Combination
The load combinations are based on IS 1893 -2000. The following load combinations are specified as per 1893 -2000: Static Load Combination: 1.5(DL + LL) Seismic Load Combination: 1.2(DL + LL ± EQ x ± EQy) 1.5(DL ± EQx ± EQy) 0.9 DL ±1.5 EQx ±1.5 EQy The following load combinations are used during analysis
Table 2: Load Combination
S.N Name
Type
1
1.5(DL + LL)
1.5(DL + LL)
2
1.2(DL + LL+ EQx)
1.2(DL + LL+ EQx)
3
1.2(DL + LL - EQx)
1.2(DL + LL - EQx)
4
1.2(DL + LL + EQy)
1.2(DL + LL + EQ y)
5
1.2(DL + LL - EQy)
1.2(DL + LL - EQy) Page | 13
3.4
6
1.5(DL + EQx)
1.5(DL + EQx)
7
1.5(DL - EQx)
1.5(DL - EQx)
8
1.5(DL + EQy)
1.5(DL + EQy)
9
1.5(DL - EQy)
1.5(DL - EQy)
10
0.9DL + 1.5EQx
0.9DL + 1.5EQx
11
0.9DL - 1.5EQx
0.9DL - 1.5EQx
12
0.9DL + 1.5EQy
0.9DL + 1.5EQy
13
0.9DL - 1.5EQy
0.9DL - 1.5EQy
Estimation of Load
The loads on the building are based on Indian codes of Practices. The unit weight of different structural and non-structural elements are derived from IS 875 Part 1 and presented in below Table 3. The load calculations are based on actual measured drawings. The selfweight of beams, columns and slabs are calculated by the program. Similarly the 2 imposed loads are applied on the slab as area load in KN/m and values of imposed loads are tabulated below. The weight of infill walls are calculated and applied on beams as line weight in KN/m. Partition wall load are assigned as uniformly distributed area load in slab as 2 area load in KN/m .
Floor finishing load are assigned as area load in slab.
Single type of Live load is assigned in each panel of slab.
3.4.1
A frame load is applied as parapet loading on the exterior frame of the roof level. The roof is assumed accessible and loaded with roof live load as per Indian Standard, IS 875 -1987(part2) but this load is not considered during seismic load.
Unit Weight (Dead Load)
Dead loads for analysis are calculated as per Indian Standard, IS 875 1987(part1). Unit weights of different material used are given below Table 3: Unit Weight of Materials
S.N
Type
Value
1
Reinforced Concrete
25 KN/m
3
Page | 14
3
2
Brick Masonry
16.5 KN/m
3
Screed
21.0 KN/m3
4
Marble
26.7 KN/m
5
Mosaic finish
23.1 KN/m
6
Plaster
20.4 KN/m
7
Steel Rebar
78.6 KN/m
3 3 3 3
Table 4: Dead Load Calculation
1 Unit Weights of materials Brick masonry Screed Mosaic Marble Reinforced Concrete cement plaster 2 Heights of Beams, Walls & Parapet Walls Depth of Beam
16.5 21 23.1 26.7 25 20.4
kN/m kN/m kN/m kN/m kN/m kN/m
0.350 m
Height of Building
2.870 m
Height of Parapet Wall Wall thickness
1.000 m 0.23 m
3 Dead Loads of Walls a) Dead load of 230 mm thick wall with inside and outside plaster 32.5 mm 1.587 KN/m Total Dead load of 230 mm thick wall with 25 % opening (Outer wall) with inside and outside plaster 32.5 mm 1.190 KN/m Total Dead load of 230 mm thick wall with 15% opening (Inner wall) with inside and outside plaster 32.5 mm 1.349 KN/m Total b) Dead load of 115 mm thick wall with inside and outside plaster 32.5 mm 1.587 KN/m Total Dead load of 115 mm thick wall with 25 % opening (Outer wall) with inside and outside plaster 32.5 mm 1.190 KN/m Total Dead load of 115 mm thick wall with 15% opening (Inner wall)
9.082 kN/m 10.669 KN/m 6.812 kN/m 8.002 KN/m 7.720 kN/m 9.069 KN/m 4.541 kN/m 6.128 KN/m 3.406 kN/m 4.596 KN/m 3.860 kN/m Page | 15
c)
with inside and outside plaster 32.5 mm 1.349 Dead load of parapet wall (230 mm thick) with inside and outside plaster 32.5 mm 0.663 Dead load of parapet wall (115 mm thick) with inside and outside plaster 32.5 mm 0.663
KN/m Total
5.209 KN/m 3.795 kN/m
KN/m Total
4.458 KN/m 1.898 kN/m
KN/m Total
2.561 KN/m
4 Floor Loads Thickness of slab Thickness of tile with plaster Thickness of Mosaic Thickness of Marble Thickness of Screed Thickness of Cement Plaster
0.125 0.025 0.020 0.020 0.040 0.0125
m m m m m m 2
Dead load of structural slab
3.125 kN/m
Dead load of Tile Dead load of Mosaic Dead load of Marble Dead load of screed Dead load of Cement Plaster Total dead load of Floor Finishes (Tile) Total dead load of Floor Finishes (Mosaic) Total dead load of Floor Finishes (Marble) Total dead load of Floor Finishes (Cement Punning)
0.510 0.462 0.534 0.840 0.255 1.350 1.302 1.374
Dead load of light partition walls
1.200 kN/m
kN/m kN/m kN/m kN/m 2 kN/m 2 kN/m 2 kN/m 2 kN/m 2
1.095 kN/m
2
Page | 16
Figure 2: Frame Load (Wall Load) on Grid E-E
Figure 5: Frame Load (Wall Load) on Grid 2-2
Page | 17
3.4.2
Live Load
The magnitude of live load depends upon the type of occupancy of the building. These are to be chosen from code IS875:1987(part II) for various occupancies. The live load distribution varies with time. Hence each member is designed for worst combination of dead load and live loads. Live loads for residential cum commercial building are given above. Table 5: Live Load for Residential Building
S.N
Area type
Load
Unit
1
Rooms
2
KN/m
2
Terrace (Accessible)
1.5
KN/m
3
Staircase and Passage
3
KN/m
2
Figure 5: Area Load (Live Load) on Floor Slab
Page | 18
Figure 5: Area Load Floor finish on Floor Slab 3.4.3
Seismic Load
The seismic load is applied to the building with auto lateral load pattern in ETABS 2013 as per IS 1893-2000. This load case is assumed static linear and all the necessary data are given as per the following conditions. To determine the seismic load, it is considered that the country lies in the seismic zone V according to IS 1893:2000. The soil type is considered as soft with 5% damping to determine average response acceleration. The building is analyzed as moment resisting frame without consideration of infill wall. Therefore the fundamental time period T a is obtained by using the following formula: Ta = [Cl.7.6.2, IS 1893 -2002] Other factors considered for seismic load calculations are as follows Zone factor, Z = 0.36 for Zone V [Table 2, Cl6.4.2, IS 1893 -2002] Page | 19
Importance factor, I = 1.0 [Table 6, Cl6.4.2, IS 1893 -2002] Response Reduction Factor = 5 for special RC moment resisting frame (SMRF) [Table 6, Cl6.4.2, IS 1893 -2002] The seismic weight is determined based on the following mass source. (Table 6, Cl.7.9.2, IS 1893 (Part 1):2002)
Table 6: Mass Source for Seismic Load
4
S.N
Load Type
Scale Factor
1
Dead Load
1
2
Live Load <3
0.25
3
Live Load >3
0.50
4
Roof Live Load
Nil
Analysis Output The analysis results are discussed in this chapter. Both seismic coefficient and
response spectrum methods are used. The major discussion are focused on the eccentricity, story shear, inter story drift, maximum displacement and base shear along two orthogonal directions. The column and beam size and reinforcement are then checked. 4.1
Seismic Coefficient Method
The fundamental time period of the building as per IS code 1893: 2002, clause 7.6.2, total seismic weight and base shear in both orthogonal directions are given in Table 7. This result will be used to compare and scale the base shear from response spectrum method. Table 7: Fundamental Time period
Direction
Time period (sec)
X
0.71
Y
0.71
Page | 20
Based on program/software calculated seismic coefficient, base shear and storey shear are as shown in the Table 8 and to calculate these parameters, the following equation has been used as per code. The coefficient is given by,
And, base shear is given by,
These values in both the orthogonal direction are tabulated in the Table 8 below. Table 8: Seismic coefficient and base shear
Seismic Weight (KN)
4.2
6571.66
Direction
X
Y
Seismic Coefficient
0.06
0.06
Vb (KN)
394.3
394.3
Story Drift
As per Cl. no. 7.11.1 of IS 1893-2002, the story drift in any story due to specified design lateral force with partial load factor of 1.0, shall not exceed 0.004 times the story height. In this building the story drift is limited to 52.4 mm. From the analysis the displacements of the mass center of various floors are obtained and are shown in along with story drift.
Page | 21
Figure 3: Story displacement (EQx)
Figure 4: Story displacement (EQy)
It is seen that drift does not exceed the code prescribed value of 0.004 times story height (i.e. permissible story displacement is 52.4 mm). Thus the drift check seems to comply with the safety value mentioned in the code. 4.3
Modal time period and mass participation
IS 1893: 2002 clause 7.8.4.2 states that number of modes to be used in the analysis should be such that the sum total of modal masses of all modes Page | 22
considered is at least 90 percent of the total seismic mass of the structure. Analysis was carried out for first 12 modes so that the mass participation satisfies this criterion in both orthogonal directions.
5
Force Diagram The output of forces obtained from ETABS analysis for Envelope have presented below as a sample only. The output forces are axial force, Shear force and Momnts.
5.1.1
Axial Force Diagram
Figure 5: Envelope - Axial Force diagram: Grid E-E
Page | 23
Figure 11: Envelope - Axial Force diagram: Grid 2-2
5.1.2
Shear Force Diagram
Page | 24
Figure 12: Envelope-Shear Force diagram: Grid E-E
Figure 13: Envelope-Shear Force diagram: Grid 2-2
Page | 25
5.1.3
Moment Diagram
Figure 6: Envelope -Moment diagram: Grid E-E
Figure1 5: Envelope -Moment diagram: Grid 2-2
Page | 26
5.2
Joint Reactions
The reactions at the support of column for load combination of (DL + LL) are as follows:
Figure 7: Joint Level and Reactions 6
Design of Structural Members (Sample Design)
6.1 6.1.1
Design Input and Output Section Input Diagram
Page | 27
Figure 17 Section Input in Frame along Grid E-E
Figure 18 Section Input in Frame along Grid 2-2
Page | 28
Figure 8: Section Input in Ground Floor
6.1.2
Design Output Diagram
Page | 29
Figure 9: Design Output in Frame along Grid E-E
Page | 30
Figure21: Design Output in Frame along Grid 2-2
Figure23: Design Output in First Floor
Page | 31
6.2
Design of Slab
DESIGN OF TWO WAY SLAB:
1 General Data: Depth of slab : Grade of Concrete : Grade of Steel : Effective cover: Effective depth of slab : Effective length: Shoter span: Longer span:
(D) (fck)
125 mm 20 N/mm2
(fy) (d') (d)
500 N/mm2 20 mm 105 mm
(lx) (ly)
4.49 m 4.87 m
2.0 Loading:
3.125 KN/m
2
(ODL)
2 KN/m
2
Live Load:
(LL)
2 KN/m
2
Total Load:
(w)
7.125 KN/m
2
Factored Load:
(wu)
10.68 KN/m
2
Dead Load: Other Dead Load:
(DL)
3.0 Type of slab:
1.107 Type:
Two way Slab
4.0 Calculation of Moments: Moment coefficient: Type of Slab Panel:
Short span coefficient: Support Mid Span Long span coefficient: Support Mid Span Moments: Short span moments: Support Mid Span
4
αx S M
0.053 0.040
αy S M
0.047 0.035
S M
11.52 8.69
KN-m KN-m Page | 32
Long span moments: Support Mid Span 5.0
S M
10.12 KN-m 7.54 KN-m
Check depth for maximum Moments: Maximum moments: Mu Moment coefficient: k
effective depth:
d
11.526 0.138 65 OK
KN-m < 105 mm
6.0 Calculation of reinforcement: 6.1 For shorter span
Mim'm reinforcement Design moment: Neutral axis depth : Area of steel required: Area of steel provided:
For longer span Effective depth
Mim'm reinforcement Design moment: Neutral axis depth : Area of steel required: Area of steel provided:
(Ast)min Mx x Ast Ø S
327 mm 8 mm 150 mm
2
Ast
336 mm
2
Pt
0.32 %
d (Ast)min Mx x
97 mm 2
117 mm 10.127 KN-m 16 mm
Ast Ø S
311 mm 8 mm 150 mm
2
Ast
336 mm
2
Pt 7.0
2
126 mm 11.526 KN-m 17 mm
0.347 %
Check for shear stress:
Maximum shear force:
Vu
23.99 KN
Shear Stress:
tv
2
β
0.229 N/mm 7.257
Concrete Shear Strength: Shear Strength factor:
tc K
0.399 N/mm 1.3
2
Shear Strength of Slab:
tc
'
0.518 > 0.229 N/mm2 OK Page | 33
8.0 Check for development length:
Ultimate moment Capacity: Maximum Shear Force:
M1 V
11.89 KN-m 23.99 KN
Bond Stress:
tbd
1.92 N/mm
Development length:
Ld
377 mm
Anchorage length: Available length:
L0
105 mm 750 OK
2
> Ld
8.0 Check for deflection:
length to eff. Depth ratio:
l/d
α β ϒ δ λ Coefficient:
42.76 23 1 2.000 1
for fs =
and P =t 1 46.00 O.K
234.25 N/mm 0.32 %
Page | 34
2
6.2
Design of Beam (Ground Beam A-B-5 X Direction)
ETABS 2015 Concrete Frame Design IS 456:2000 Beam Section Design
Beam Element Details Type: Ductile Frame (Summary) Level Element Section ID Combo ID Station Loc
Story1
Beam 350*230
B19
UDCon7
Length (mm)
LLRF
6798.9
1
6623.9
Section Properties b (mm) h (mm) bf(mm) 230 350 230
d s(mm) 0
d ct(mm) 30
d
cb
(mm) 30
Material Properties Ec(MPa) f
22360.68
ck
(MPa)
27.58
Lt.Wt Factor (Unitless) 1
fy(MPa) f
413.69
ys
(MPa)
413.69
Design Code Parameters ɣC
ɣS
1.5
1.15
Factored Forces and Moments Factored Factored Factored Factored Mu3 Tu Vu2 Pu kN-m kN-m kN kN -96.1357 0.1114 66.7442 0 Design Moments, Mu3 & Mt
Page | 35
Factored Factored Positive Negative Moment Mt Moment Moment kN-m kN-m kN-m kN-m -96.1357 0.1653 0 -96.301 Design Moment and Flexural Reinforcement for Moment, M u3 & Tu Design Design -Moment +Moment Minimum Required -Moment +Moment Rebar Rebar Rebar Rebar
Top (+2 Axis) Bottom (-2 Axis)
kN-m -96.301
kN-m
mm² 1039
mm² 0
mm² 1039
mm² 260
0
519
0
67
519
Shear Force and Reinforcement for Shear, Vu2 & Tu Shear Ve kN 87.2234
Shear Vc kN 54.0464
Shear Vs kN 38.3579
Shear Vp kN 33.9899
Rebar Asv /s mm²/m 333.22
Torsion Force and Torsion Reinforcement for Torsion, T u & VU2 Tu Vu kN-m kN 0.7447 64.476
6.3
Core b1 mm 190
Core d1 mm 310
Rebar Asvt /s mm²/m 266.42
Design of Beam (Ground Beam 1-4-F-G Y Direction) ETABS 2015 Concrete Frame Design IS 456:2000 Beam Section Design
Page | 36
Beam Element Details Type: Ductile Frame (Summary) Length Level Element Section ID Combo ID Station Loc LLRF (mm) Beam Story1 B15 UDCon10 175 4511.9 1 350*230 Section Properties b (mm) h (mm) bf(mm) 230 350 230
d s(mm) 0
d ct(mm) 30
d
cb
(mm) 30
Material Properties Ec(MPa) f
22360.68
ck
(MPa)
Lt.Wt Factor (Unitless)
27.58
fy(MPa) f
1
413.69
ys
(MPa)
413.69
Design Code Parameters ɣC
ɣS
1.5
1.15
Factored Forces and Moments Factored Factored Factored Factored Mu3 Tu Vu2 Pu kN-m kN-m kN kN -96.2489 2.4386 78.5173 0.0783 Design Moments, Mu3 & Mt Factored Factored Positive Negative Moment Mt Moment Moment kN-m kN-m kN-m kN-m -96.2489 3.6173 0 -99.8662 Design Moment and Flexural Reinforcement for Moment, M u3 & Tu
Page | 37
Design Design -Moment +Moment Minimum Required -Moment +Moment Rebar Rebar Rebar Rebar kN-m kN-m mm² mm² mm² mm²
Top (+2 Axis) Bottom (-2 Axis)
-99.8662 0
1073
0
1073
268
537
0
102
537
Shear Force and Reinforcement for Shear, V & T Shear Ve kN 96.5561
Shear Vc kN 54.6695
Shear Vs kN 69.2863
Shear Vp kN 55.3635
u2
u
Rebar Asv /s mm²/m 601.9
Torsion Force and Torsion Reinforcement for Torsion, T u & VU2 Tu Vu Core b1 kN-m kN mm 3.9387 72.7703 190
Core d1 mm 310
Rebar Asvt /s mm²/m 446.92
Page | 38
Table 9: Beam reinforcement details Beam Reinforcement Detail Reinforcement
S.N.
1
Type of beam
Tie beam
Size of beam
Dir
At support Top
Bottom
Top
Bottom
X-dir
3-12ØR
3-12ØR
3-12ØR
3-12ØR
Y-dir
3-12ØR
3-12ØR
3-12ØR
3-12ØR
3-16ØR
2-16ØR
230*230
X-dir 2
Main beam
At center
2-20ØE+2-16ØR
3-16ØR
230*350 Y-dir
3-16ØR 2-20ØE+2-16ØR
2-16ØR
3-16ØR
Page | 39
6.4
Design of Column(Ground D-3) ETABS 2015 Concrete Frame Design IS 456:2000 Column Section Design
Column Element Details Type: Ductile Frame (Summary) Level Element
Story2
Section ID Combo ID Station Loc
Column 350*350
C10
UDCon9
0
Length (mm)
LLRF
2844.8
0.801
Section Properties b (mm) h (mm) dc (mm)
350
350
65.2
Cover (Torsion) (mm) 28.1
Material Properties Ec(MPa) f
22360.68
ck
(MPa)
27.58
Lt.Wt Factor (Unitless) 1
fy(MPa) f
413.69
ys
(MPa)
413.69
Design Code Parameters
Design Pu kN
928.2852
ɣC
ɣS
1.5
1.15
Axial Force and Biaxial Moment Design For P u , Mu2 , Mu3 Rebar Design Mu2 Design Mu3 Minimum M2 Minimum M3 Area kN-m kN-m kN-m kN-m mm² 88.8077 100.3549 18.5657 18.5657 4254
Rebar % %
3.47
Axial Force and Biaxial Moment Factors
Page | 40
Major Bend(M3) Minor Bend(M2)
K Factor Length Unitless mm
Initial Moment kN-m
Additional Moment kN-m
Minimum Moment kN-m
3.305575 2494.8
6.339
81.7892
18.5657
1.419206 2494.8
35.5231
0
18.5657
Shear Design for V Shear Vu Shear Vc Shear kN kN kN Major, Vu2 0 126.9456 39.8653 Minor, V58.9787 126.9456 39.8653 u3
,V u2 Vs
u3
Shear Vp Rebar Asv /s kN mm²/m 0 389.18 0 389.18
Joint Shear Check/Design Joint Shear Shear Force VTop kN kN
Major Shear, Vu2 Minor Shear, Vu3
Shear Vu,Tot kN
Shear Vc kN
Joint Area cm²
Shear Ratio Unitless
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
(1.1) Beam/Column Capacity Ratio Major Ratio N/A
Minor Ratio N/A
Additional Moment Reduction Factor k (IS 39.7.1.1) Ag cm²
Asc cm²
1225
42.5
Puz Pb Pu k kN kN kN Unitless 2839.824 731.992 928.285 0.906875 9 3 2
Additional Moment (IS 39.7.1) Consider Length Ma Factor
Major Bending (M3 ) Minor Bending (M2 )
Section Depth (mm)
KL/Dept KL/Dept KL/Dept Ma h h h Moment (kNRatio Limit Exceeded m)
Yes
0.877
350
23.562
12
Yes
90.188
Yes
0.877
350
10.116
12
No
0
Page | 41
Notes: N/A: Not Applicable N/C: Not Calculated N/N: Not Needed
Page | 42
Table 10: Summary of Design of Column
Grid S.N. Location 1 A-5 2 B-3 3 B-6 4 C-2 5 C-3 6 D-1 7 D-2 8 E-1 9 E-2 10 E-3 11 E-4 12 f-1 13 G-2 14 G-3 15 H-3
Column Size 350 x 350 350 x 350 350 x 350 350 x 350 350 x 350 350 x 350 350 x 350 350 x 350 350 x 350 350 x 350 350 x 350 350 x 350 350 x 350 350 x 350 350 x 350
Ground Floor and first floor 5-20Ø+5-25Ø 5-20Ø+5-25Ø 5-20Ø+5-25Ø 5-20Ø+5-25Ø 5-20Ø+5-25Ø 10-20Ø 10-20Ø 10-20Ø 10-20Ø 5-20Ø+5-25Ø 5-20Ø+5-25Ø 10-20Ø 5-20Ø+5-25Ø 5-20Ø+5-25Ø 5-20Ø+5-25Ø
Second and Third floor 10-16Ø 10-16Ø 10-16Ø 10-16Ø 10-16Ø 10-16Ø 10-16Ø 10-16Ø 10-16Ø 10-16Ø 10-16Ø 10-16Ø 10-16Ø 10-16Ø 10-16Ø
Fourth Floor
Top Floor
5-16Ø+5-12Ø 5-16Ø+5-12Ø 5-16Ø+5-12Ø 5-16Ø+5-12Ø 5-16Ø+5-12Ø 5-16Ø+5-12Ø 5-16Ø+5-12Ø 5-16Ø+5-12Ø 5-16Ø+5-12Ø 5-16Ø+5-12Ø 5-16Ø+5-12Ø 5-16Ø+5-12Ø 5-16Ø+5-12Ø 5-16Ø+5-12Ø 5-16Ø+5-12Ø
10-12Ø 10-12Ø 10-12Ø 10-12Ø 10-12Ø 10-12Ø 10-12Ø 10-12Ø 10-12Ø 10-12Ø 10-12Ø
Stirrups 8mm Ø stirrups @
Remark
100 mm C/C (at top and bottom) & @ 150 mm C/C (at mid height) in all columns
10-12Ø
Page | 43
6.5
Design of Footing
Sample De sign of i solated footi ng (F 3).
A)
Given Data
Size of column B=c D=c Column Load (V) = Bearing Capacity (qa) = Grade of Concrete (fck) = Grade of Steel (f y)= B)
Calculation of size of footing wt. of foundation = Total Load (P)=
350 mm 350 mm 659.54 KN 120 KN/m2 20 Mpa 500 Mpa
65.954 KN 725.49 KN 2
Area of footing = 6.046 m *Note: Taking the ratio of width and length of footing same as that of column dimensions Size of footing L= B= Provided (L) = Provided (B) =
C)
m m m m
Upward reaction (q') =
158.29 KN/m
Max'm B.M. =
91.46 KN-m
Calculation for depth of footing
B.M. = depth (d)= Provided depth (d) = D)
2.45 2.45 2.5 2.5
2
0.134 fckbd 184.73 mm 350 Mm
Check for Shear
Per. Shear Strength (τc) =
0.25√fck 1.118 N/mm
2
a) Punching shear depth (d)=
Punching shear(τ'V) = Provided depth (d) = Overall Depth (D)=
350 mm 1.01 N/mm
2
Revise depth 350 mm 400 mm
Page | 44
2
Punching shear(τ'V) =
0.748 N/mm Ok b) One way Shear (Calculation for no shear reinforcement) depth (d) = 350 mm Max'm S.F. = 114.76 KN
One way Shear (τv) = Provided Ast =
β= Concrete Shear strength (τc)=
0.328 N/mm 0.25
2
%
9.29 0.359 N/mm
2
Ok
Ast = E)
875 mm
2
Calculation for reinforcement
A = st A required = st Provided, Size = Spacing =
630 mm
2 2
875 mm 12 mm dia 125 mm c/c 2
st AProvided=
904.779 mm Ok Area of Steel Along width B.M. = 91.46 KN-m
A = st Provided, Size = Spacing = Provided= Ast
F)
2
875 mm 12 mm dia 125 mm c/c 905 mm Ok
2
Development Length
Bond stress(τbd)= Development length (Ld)= Available Ld along length =
1.920 N/mm2 680 mm 1025 mm Ok
G)
Load Transfer from Column to Footing
Nominal bearing stress in column =
4.917 N/mm
2
Page | 45
Allowable bearing stress =
0.45*fck 9.000 N/mm2 0.000 kN
Now Excess load =
Area of steel required As = 0 mm2 Minimum Ast = 0.5% of column area 450 mm
2
450 mm2
Thus, area of steel for dowel bars = Now Bar extended Nos 5 5
dia 20 25
Ast 1570.7 2454.2 2
Available Ast for load transfer =
4025 mm
Thus no additional dowel bars are required to transfer load Additional Ast = No dowel bars are needed
Combine Footing Design
A )
Given Data
Column Size of column Bc = Dc = Column Load (working load)(V) = Distance bet'n column =
m
0.35 232.667
m KN 1.524 KN/m
120
2
Grade of Concrete (fck) =
20
Mpa
Grade of Steel (f y)=
500
Mpa
Calculation of size of footing wt. of foundation = Total Load (P)=
70.6993 777.693
KN KN
6.481
m
1.023
m
Bearing Capacity (qa) =
B )
1 0.35
Column
Area of footing = C.G. of loads from center of Column1 =
Projection Available = C.G. of loads from outer face of
Column 1 1 2.023
2 0.35 0.35 474.327 m
m m KN
2
m m
Column 2 1
m
Page | 46
footing = Total Footing Length ,L = Size of footing width of footing = Adopted width,b = Actual Area (A) = Upward reaction (w) = C )
3.524
m
11.56 ft
1.839 2.000
m m
6.034 ft 6.562 ft
6.481 163.637
m KN/m
Design of Slab Based on maximun bending monent at interior i) part Shear force at left edge(V1)= 0 Shear force at Column1 just left (V2)= 163.637 Shear force at Column1 just right (V3)= -185.36 Shear force at left edge(V4)= 0 Shear force at Column2 just right (V5)= 163.637 Shear force at Column2 just left (V6)= -547.85 Position of zero SF from left edge= 1.38528 Position of maxm BM from left edge= 1.38528 Maximum Bending moment(Mmax)= 92.2204
B.M. = 0.134 eff. depth required (d)= 200 ii) Maximum projection of slab = 0.825 Effective depth for maximum bending moment
2
KN KN KN KN KN KN m m KN-m fckbd2 mm m
Max'm B.M. =
55.688
KNm/m
B.M. = eff. depth required (d)=
0.134 143
fckbd mm
135.001 0.200 11.61
KN %
2
ii) Effective depth for maximum shear force
Max'm S.F. = Assumed, Ast =
β=
N/mm
Shear strength of concrete(τc) = eff. depth required (d)= eff. depth provided (d)= Overall depth (D) =
0.326 413.804 400 450
2
mm mm mm
iii ) Reinforcement Page | 47
a) For max'm B.M.
B.M. = =
Ast
)min= (Ast b) For max'm S.F. =
Ast Required, = Ast
55.688 327 480
800 800
Provided, Size =
2
mm mm
mm
125 905
iv ) Transverse Reinforcement From Empirical Relation Hogging Moment = Sagging Moment =
2
2
mm
12
Spacing = Provided= Ast
KN-m
mm OK
2
mm dia mm C/C 2
19.003 15.836
kN-m kN-m
0.134 83 OK
fckbd mm
Check for depth B.M. = eff. depth required (d)=
2
Reinforcement Bottom, = Ast
480
mm
Provided, Size =
12
Spacing =
125
Provided= Ast = Top, Ast
905 480
Provided, Size =
mm 12
Spacing = Provided= Ast
mm OK
125 905
mm OK
2
mm dia mm C/C 2
2
mm dia mm C/C 2
V) Check for punching Shear
Page | 48
=
0.25√fc Per. Shear Strength (τc) Max'm S.F. = Punching shear(τ'V) =
k 711.49
1.118 KN N/mm
0.791 OK
2
2
N/mm
Page | 49
Table 11: Summary of Design of Footing
Footing Details Soft Soil: Bearing Capacity = 120 KN/m
Footing Type:
Grid Location
Isolated Footing (F3)
Foundation Plan
Concrete Grade: M20
Steel Grade: Fe500
Thickness (in)
Reinforcement Detail
LXB (Ft-in)
Edge (d1)
Overall (D)
E-2G-2-H-3
8 ’0”X8’0”
8”
16”
12mm Ø @ 5" c/c
Isolated Footing (F3)
D-1,E-1,F-1
6’0”X6’0”
8”
16”
12mm Ø @ 5" c/c
Combined footing (F2)
A-B-5,6,B-C,3,C-D,2E-3-4
6’0”X11’6”
8”
16”
12mm Ø @ 5" c/c
Staircase slab
Both ways
12mm Ø @ 5" c/c Main bar and
10mmɸ@150mm distribution
Page | 50
7
References
IS 456- 2000 Code of practice for plain and reinforced concrete
IS 875-1987 Code of practice for design loads (other than earthquake) for buildings and structures
IS 1893-2002 Criteria for Earthquake Resistant Design of Structures,
IS 13920-1993 Code of practice for ductile detailing of reinforced concrete structures subjected to seismic forces
NBC Nepal Building Code
Design of Reinforced Concrete Structure – A.K. Jain
Limit State Design of Substructure- Swami sharan
ETABS manual V 13
Page | 51
STRUCTURAL DESIGN (Type B) Building Elements
As Per Submitted Design
Remarks
General
Building Structure Type
Frame Structure
Number of story applied for permit (in No’s)
6
Number of story considered in structure design (in No’s)
6
If Computer Aided Design (CAD) is used, please State the name of the software package
ETABS 2015
Number of story considered in structure design provision for further extension Total height (h) 0f structure with extension (in m)
No.
19.82 m
NBC 101-1994 MATERIALS SPECIFICATIONS
Materials to be used in structure (tick the listed materials that will be used in structure element
RCC (Reinforcement Bar)
NBC 102-1994 UNIT WEIGHT of MATERIALS
Specified the design unit weight of
7850
materials: Steel (In kg/m^3) Specified the design unit weight of materials:RCC (In kg/m^3)
2500
Specified the design unit weight of materials: Brick Masonry (In kg/m^3)
1920
NBC 103-1994 OCCUPANCY LOAD (Imposed Load)
Page | 52
For Residential Buildings
Occupancy Load (Uniformly Distributed load in KN/m^2) for Rooms and Kitchen
2
Occupancy Load (Uniformly Distributed load in kN/m^2) for Staircase
3
Occupancy Load (Uniformly Distributed load in kN/m^2) for Balcony
3
NBC 104-1994 Wind load
Wind Zone
N/A
Basic wind speed (in m/s) NBC 105-1994 Seismic Design of Buildings in Ne pal
Seismic Coefficient Approach Method adopted for earthquake resistant design
seismic
Adopted Code for Seismic Design
IS 1893
Subsoil category
Type II (Soft)
Seismic Weight (W) (in kN)
1893
6571.66
Fundamental Time Period of the building 0.71 along X (Tx)(in Seconds) Fundamental Time Period of the building 0.71 along Y(Ty)(in Seconds) Response reduction factor (R)
5
Seismic zoning factor (Z)
0.36
Importance Factor (I)
1
Spectral acceleration coefficient (S a/g) along X
2.5
Spectral acceleration coefficient (S a/g) along Y
2.5
Page | 53
Design Horizontal Seismic Coefficient Along X (Ah)
0.06
Design Horizontal Seismic Coefficient Along Y (Ah)
0.06
Base Shear(VB) for Seismic Coefficient Along X 394.3 Base Shear(VB) for Seismic Coefficient Along Y 394.3 Base Shear Generated through dynamic Analysis Along X (if response spectrum method used)
N/A
Due to seismic coefficient
Base Shear Generated through dynamic Analysis Along Y (if response spectrum method used)
N/A
Adopted Base Shear multiplication Factor Along X(if response spectrum method used)
N/A
Adopted Base Shear multiplication Factor Along Y(if response spectrum method used) Base Shear after Scale Factor Along X Base Shear after Scale Factor Along Y 6.34 Maximum Inter-story Drift mm Corresponding Story height for Maximum Inter Story Drift (h) NBC 106-1994 Snow Load
2.87 m no
Snowfall type or condition No snowfall Elevation of construction site (in m) Design Depth of snow (in cm) Design Density of snow (in g/cm )
Page | 54
NBC 107-1994 Provisional Recommendation on Fire safety
Have you considered fire safety requirement?
Yes No
no
NBC 108-1994 Site Consideration for Seismic Hazards
Whether Distance of construction site from toe/beginning of downward slope is within 50m?
Yes No
Whether Distance of construction site from river bank is within 50m?
Yes No
no
Availability of soil test report
Yes No
no
Yes No
yes
no
NBC 114-1994 Construction Safety
Are you sure that all safety measures will be fulfilled in the construction site as per this code?
Safety hard hat Safety goggles Safety wares used
Safety boots
yes
Safety belts First aid facility Structural Data for Framed RCC Structure NBC 110-1994 Plain and Reinforced Concrete
M20 M25 Concrete grade in structure
Reinforcement Steel Grade
M20 for All
Fe-415 Fe-500
Fe415 for all
Slab design
Page | 55
1 short side discontinuous 2 adjacent side continuous
1 short side discontinuous
Boundary condition of slab
Effective Thickness of slab (d) (in mm)
105
Is code
4490 Short span of Critical slab panel (L) (in mm)
mm Calculated short span to effective depth ratio 42.76 (L/d) for the corresponding slab Basic (L/d) ratio
23
Required modification factor for reinforcement
tension
1.85
Required Tension Percentage (%) for reinforcement
reinforcement (Ast) short span bottom 0.32
Provided Percentage
reinforcement (A st) short span bottom 0.32
Tension (%) for
reinforcement Actual Modification factor for reinforcement
tension
1.6
Check for Critical beam
Effective depth of beam (d) (in mm)
310
Page | 56
Critical span (L) (in mm)
4970 One side discontinuous
Support condition Both side continuous Basic (L/d) ratio
23
Calculated critical span to effective depth ratio 16.03 (L/d) for corresponding slab Check for Critical Column
Critical column height
2.870 m 350*350
Minimum size of column (mm x mm)
Yes No
Short column effect considered or not
Minimum area Provided (%) Design Philosophy
yes
of longitudinal reinforcement 1.0 Limit state method
Limit state method
Load Combinations
1: DL
1.5
1: LL
1.5
2: DL
1.5
2: EQ
1.5
3: DL
1.2
3: LL
1.2
3: EQ
1.2
4: DL
0.9
4: EQ
1.5
Page | 57
Whether sample design calculations of foundations, columns, beams and slabs are submitted
Type of Foundations
Depth of foundation from ground level to the 1.5 bottom of footing (in m)
Yes No
yes
Isolated & Combined
1.5
Page | 58
