structural engineering calculations for ...asuc.thepremierguarantee.co.uk/documents/28295...lower...

DESIGN CALCULATION SHEET

Project Designed JS Date March 17 Project No: GA21713 16E, THE GREEN, DARTFORD, KENT, DA2 6JR Checked RM Date March 17 Sheet No. CALC/01

STRUCTURAL ENGINEERING CALCULATIONS

FOR UNDERPINNING

PILED RAFT FOUNDATION

AT

16E, THE GREEN

DARTFORD

DA2 6JR

ISSUE 1. 07th March 2017



CONTENTS

Description. Page No. Loadings Calc/03-04

Structural Statement Calc/05

Pile Loads Calc/06-09

Contours of Reinforcement Calc/10-13

Working Pile Load Table Calc/14

Punching Shear Checks Calc/15

Nib Reinforcement Checks Calc/15

Stooling Checks Calc/16-17

Appendix A: Input Loads Calc/A

Appendix B: AP Load Take Down Calc/B



Loadings (γf = 1.0) Abbey Pynford have summarised the superstructure loadings below in order to undertake our own load take down which is illustrated in the Appendix B. These loadings have then been applied at slab level within the Finite Element Analysis. All loads given are Unfactored.

1. Roof Loading (35˚ Pitch) Dead Load Tiles = 0.75 kN/m

2

Felt / Insulation / Battens = 0.05 kN/m2

Trussed Rafters = 0.25 kN/m2

1.05 kN/m2 allowing for 35

o roof pitch = 1.05/cos35 = 1.30 kN/m

2

+ Insulation, P.board & Skim = 0.30 kN/m

2

and Ceiling Joists DL = 1.60 kN/m

2

Live Load Roof allowance (No access) = 0.60((60-35)/30) = 0.50 kN/m

2

Services Allowance = 0.25 kN/m2

LL = 0.75 kN/m2

2. 1st

Floor Loadings (Domestic) Dead Load Floor Boards = 0.15 kN/m

2

Floor Joists = 0.20 kN/m2

P.board & Skim = 0.15 kN/m2

Partition Allowance = 1.00 kN/m2

DL = 1.50 kN/m2

Live Load Domestic Allowance = 1.50 kN/m

2

LL = 1.50 kN/m2

3. External Walls Cavity Birck / Block Wall Dead Load Internal finishes = 0.30 kN/m

2

Insulation = 0.10 kN/m2

102.5mm Brickwork = 2.10 kN/m2

100mm Blockwork = 1.50 kN/m2

DL = 4.0 kN/m2

4. Internal Walls

Internal Load Bearing Walls

Dead Load Internal finishes (on both side) = 0.50 kN/m

2

100mm Blockwork = 1.50 kN/m2

DL = 2.00 kN/m2



Bay window Dead Load Timber stud wall between first floor and ground floor windows & window allowance = 1.00 kN/ m

2

DL = 1.00 kN/m2

5. Ground Floor Loading (Domestic)

Dead Load 225mm R.C. Slab = 5.40 kN/m

2

75mm Screed = 1.80 kN/m2

75mm Insulation = 0.10 kN/m2

Partition allowance = 1.00 kN/m2

DL = 8.30 kN/m2

300mm R.C. Slab (where applicable) = 7.20 kN/m2

Live Load Domestic allowance = 1.50 kN/m

2

LL = 1.50 kN/m2



STRUCTURAL STATEMENT

THE PILED RAFT FOUNDATION WILL BE ANALYSED USING A FINITE ELEMENT PROGRAM CALLED 'SOFISTIK SLAB DESIGNER PROFESSIONAL'.

THE PROGRAM HAS THE FOLLOWING FEATURES:-

A. INPUT OF RAFT DETAILS IN AUTOCAD 2011 ENVIRONMENT.

B. LOADING DRAWN IN AUTOCAD ENVIRONMENT AND READ BY F.E. SOFTWARE.

C. SPRING SUPPORT FACILITY FOR PILES.

D. AUTOMATIC MESHING OF THE SLAB TO FORM FINITE ELEMENT MESH WITH EDITING FACILITY.

E. CALCULATION OF MX, MY, AND MXY AND SHEAR FORCES AT CORNERS OF ELEMENTS.

F. CALCULATION OF PRINCIPAL FORCES AT CORNERS OF ELEMENTS.

G. RESOLUTION OF PRINCIPAL FORCES INTO REBAR DIRECTIONS.

H. CALCULATION OF CONTOURS OF REINFORCEMENT REQUIRED TOP AND BOTTOM EACH WAY IN TERMS OF mm2/m.

I. AUTOMATIC PATTERN LOADING FACILITY TO ENSURE WORST CASE FORCES ARE OBTAINED.

J. CALCULATION OF SUPPORT FORCES.

K. DESIGN CODE SELECTION: BS8110

THE FOLLOWING PARAMETERS WILL BE USED:-

o fcu = 35 N/mm2

o MINIMUM TOP REINFORCEMENT = H12–200 T1 & T2 o MINIMUM BOTTOM REINFORCEMENT = H12–200 B1 & B2 o TOP COVER = 35mm o BOTTOM COVER = 40mm o PILE DIAMETER = 200mm o 1% OF PILE DIAMETER = 2.0mm o PILE SAFE WORKING LOAD = 166 kN o PILE SPRING STIFFNESS = 166/2.0*10

-3 = 83000 kN/m

(EQUIVALENT TO A VERTICAL ELASTIC DISPLACEMNT OF 1% OF PILE SIZE AT S.W.L.)

o SLAB THICKNESS = 225mm with a 300mm thickening around the perimeter



Maximum Working Pile Load



Minimum Working Pile Load



Maximum Ultimate Pile Loads



Minimum Ultimate Pile Loads



Upper Principal Reinforcement T1 (Design Case 1 where punching shear checks are turned on)



Upper Cross Reinforcement T2 (Design Case 1 where punching shear checks are turned on)



Lower Principal Reinforcement B1 (Design Case 1 where punching shear checks are turned on)



Lower Cross Reinforcement B2

(Design Case 1 where punching shear checks are turned on)



Working Pile Loads (kN)

Pile Ref (Refer to GA’s) Max

Load (kN)

P01 161

P02 116

P03 107

P04 136

P05 143

P06 148

P07 151

P08 167

P09 136

P10 150

P11 119

P12 108

P13 122

P14 100

P15 108

P16 74

P17 96



Overall punching shear checks

Punching Shear checks are included within the FE Analysis, as such the reinforcement quantities on the relevant calculation pages have already been enhanced to suit.

Nib reinforcement check (Refer to the drawings for slab edge details).

By providing a minimum 225mm deep nib with worst case outer brick wall loading of:- Pult = 1.4(56) +1.6(0.0) = 78.40 kN/m (Say 79 kN/m)

Design Shear Stress, v = 𝑃𝑢𝑙𝑡

𝑏𝑑 =

79000

1000×178 = 0.443N/mm

2

Minimum reinforcement to be provided is H12@200, So 100𝐴𝑠

𝑏𝑑 =

100×566

1000×178 = 0.318

Therefore vc = 0.591 N/mm2 > 0.443N/mm

2 so OK

Provide H12@200 U–Bars to nibs, 35mm top cover.

Project: Designed JS Date Mar-17 Project No. GA21713

Checked RM Date Mar-17 Sheet No. CALC/16

Stool Design (External Wall )

For Section: 42.4CHS4 235 Hot Finished

Section Properties

D = 42.4 mm ry = 1.36 cmt = 4.0 mm Le = 500 mm

Ag = 4.83 cm2 py = 235 N/mm

2

z = 4.24 cm3 Spacing = 0.700 m

Loadingpdead = 35.00 kN/m ɣf=1 p live = 5.00 kN/m ɣf=1

pult = 0.7m x (1.4 x 35 + 1.6 x 5) = 39.9 kN

Compression Check

λ=Le/ry = 36.76

pc = 201 N/mm2

(From Strut Curve a Table 24 BS5950)

Pc=pc*Ag = 97.0 kN > 39.9 kN

Therefore Compression Check OK

Bending Check

e = 0.01 m

Mult=Pult*e = 0.399 kNm

Mb=pyz = 0.9964 kNm > 0.4 kN/m

Therefore Bending Check OK

Combined Bending and Axial Load CheckPult/Pc + Mult/Mb < 1

0.411 + 0.400 < 1

0.812 < 1

Therefore Combined Load Check OK

Bearing Stress on BrickworkBrickwork Quality: = 3.4 N/mm

2

Mortar Quality: = 3.5

Allowable Bearing: = 1.46 N/mm2

= 0.031 m2

= 1.30 N/mm2 < 1.46 N/mm

2

Therefore Bearing Check OK

16E, The Green, Dartford, Kent, DA2 6JR

Single Stooled

NOTE: Stools to be 42.4CHS4.0 with 300x300mm plates @ 700mm c/cs. Tighter spacing is to

be used around the heavily loaded corners as indicated on the drawing.

0.10 x 0.30

Bearing Stress

300 x 300mm Plates

No Padstone

1.5fk/ɣm

fk

ɣm

Bearing Area:

Project: Designed JS Date Mar-17 Project No. GA21713

Checked RM Date Mar-17 Sheet No. CALC/17

Stool Design (Internal Wall )

For Section: 42.4CHS4 235 Hot Finished

Section Properties

D = 42.4 mm ry = 1.36 cm

t = 4.0 mm Le = 500 mm

Ag = 4.83 cm2 py = 235 N/mm

2

z = 4.24 cm3 Spacing = 0.800 m

Loadingpdead = 23.90 kN/m ɣf=1 p live = 10.10 kN/m ɣf=1

pult = 0.8m x (1.4 x 23.9 + 1.6 x 10.1) = 39.7 kN

Compression Check

λ=Le/ry = 36.76

pc = 201 N/mm2

(From Strut Curve a Table 24 BS5950)

Pc=pc*Ag = 97.0 kN > 39.7 kN

Therefore Compression Check OK

Bending Check

e = 0.01 m

Mult=Pult*e = 0.397 kNm

Mb=pyz = 0.9964 kNm > 0.4 kN/m

Therefore Bending Check OK

Combined Bending and Axial Load CheckPult/Pc + Mult/Mb < 1

0.409 + 0.398 < 1

0.808 < 1

Therefore Combined Load Check OK

Bearing Stress on BrickworkBrickwork Quality: = 3.4 N/mm

2

Mortar Quality: = 3.5

Allowable Bearing: = 1.46 N/mm2

= 0.031 m2

= 1.30 N/mm2 < 1.46 N/mm

2

Therefore Bearing Check OK

16E, The Green, Dartford, Kent, DA2 6JR

Single Stooled

Note : Stools to be 42.4CHS4.0 with 300x300mm plates @ 800mm c/cs.

0.10 x 0.30

Bearing Stress

300 x 300mm Plates

No Padstone

1.5fk/ɣm

fk

ɣm

Bearing Area:


Project Designed JS Date March 17 Project No: GA21713 16E, THE GREEN, DARTFORD, KENT, DA2 6JR Checked RM Date March 17 Sheet No: CALC/APPA/01

APPENDIX A (Input loads to FE model)



Self Weight of Slab (kN/m2)



Finishes on Slab (kN/m2)



Imposed Load on Slab (kN/m2)



Ground Floor Partition Allowance (kN/m2)



Roof Load - Dead (kN/m)



Roof Load - Live (kN/m)



Roof Point Load - Dead (kN/m)



Roof Point Load – Live (kN/m)



First Floor – Dead (kN/m)



First Floor Load – Live (kN/m)



First Floor Point Load – Dead (kN/m)



First Floor Point Load – Live (kN/m)



Ground Floor Loading – Dead (kN/m)


Project Designed MA Date May 2016 Project No: GA21259

47. OAKHILL AVENUE, PINNER – HA5 3DL Checked MJ Date May 2016 Sheet No. CALC/APPB/01

APPENDIX B (Abbey Pynford’s Load Takedown)

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