1. Build a 40 tones cement silo at narrow space
Author : Chandra Manik
Date : October 2016
Build a 40 tones cement silo at narrow
space
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2. Table of contents
1. Objective
2. Project risks
3. Technical consideration to build cement silo
4. Summary and result
5. Appendix
Appendix 1-Foundation using bore pile
Appendix 2-Stress analysis 3D Model
Appendix 3-On site erection method
Build a 40 tones cement silo at narrow
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3. 1. Project objective
The project objective is to build a 40 tones cement silo without technically disturb the
existing equipments nearby. The location of this new silo is 5 meters c/c to existing
silo with limited space available for mechanized erection and installation. The silo is
designed by utilizing the load cell to measure the cement weight for easier daily
reporting on cement consumption.
Build a 40 tones cement silo at narrow
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4. 2. Project risks
Build a 40 tones cement silo at narrow
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NO RISK RISK LEVEL MITIGATION ACTIONS
P E S R
1 Foundation
Soil must stable 6 10 40 2400 High Perform soil test and seek advices for civil engineer
Water must drained 2 10 30 600 High Provide submersible pump during construction
2 Steel Structure
Safety factor 4 to 6 2 6 40 480 High Do analysis using manual calculation or
finite element method
Welding quality 6 10 30 1800 High Hire only certified welder and check work
result regularly
3 Loadcell
Loadcell capacity 1 6 7 42 Medium Choose a loadcell with total capacity 2 times
of total load. Example : silo dead load 40 tns
Using 4 loadcell then each loadcell at least 20 tns
capacity, in total become 80 tonnes versus 45 tns
4 Erection & Installation
Silo inclination 6 6 15 540 High Check and perform field measurement to ensure
silo inclination
R (Risk index) = P (probability) * E ( exposure) * S (Severity)

5. 3. Technical consideration to build cement silo
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ITEMS WHAT TO DO
Foundation 1. Perform soil test
2. Consult the foundation depth and foundation type to be use with civil work consultant
Steel Structure 1. Design the steel structure with safety factor in the range 4 to 6
2. Do stress analysis using finite element method using static or buckling condition
Loadcell 1. Total loadcell capacity at least 2 times of silo capacity
2. Location of loadcell is best above center gravity of silo or at least coicident
Erection & Installation 1. Using hoist crane if space is possible
2. Using onsite construction for narrow space as shown in this presentation

6. 4. Summary and result
Build a 40 tones cement silo at narrow
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ITEMS WHAT TO DO
Foundation 1. Soil test performed on field and the result being used to build foundation
2. Foundation spesification shown at appendix 1, 18 meter depth and 1 meter bore pile
Steel Structure 1. Stress analysis simulation using finite element method showing a good result
with safety factor from 4 to 60 with displacement maximum 1.6 mm and elongation 0.02%
Loadcell 1. Dead load of silo is 45 tonnes, using 4 load cells with each loadcell has 20 tonnes capacity
Erection & Installation 1. On site erection as shown in appendix 3 was succesfull

7. Build a 40 tones cement silo at narrow
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APPENDIX

8. Appendix 1- Foundation using bore pile
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The bore pile foundation with depth 18
meters & diameter 1 m.The foundation cap
depth 1.5 m. Bore pile using reinforced steel
diameter 19 mm ( following Indonesian
Standard)

9. Appendix 2- Stress analysis 3D Model
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10. Appendix 2- Stress analysis load and assumptions
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Load is distributed equally at
four support as shown at the
left right. The load amount as
below :
1. Silo main body load 4.4
tonnes
2. Cement material load
maximum 40 tonnes
3. Total load 44.4, rounded to
45 tonnes.
4. 45 toness converted to
weight (multiply gravity 9,8
m/s2) become 441 kN.
5. Each support receive load
110,25 kNAssumptions :
1. Static analisys
2. Buckling effect not included due to software
license liitation

11. Appendix 2- Stress analysis fixtures location
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The four legs bottom surface where
anchors bolt attached are assigned
as fixtures and fix.

12. Appendix 2- Stress analysis mesh and material
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Mesh type is blended curvature with 8
nodes Jacobian. Total nodes 350k and
aspect ratio 221. Material is AISI 1202
with yield strength 3.51 * E+8 N/m2

13. Appendix 2- Stress distirbution on silo structure
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In general, stress
distirbution is higher at
the top section but still
half of yield strength
and getting smaller at
the lower section
(near the structure
foundation).

14. Appendix 2- Critical stress distribution on silo structure
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The maximum stress
location is at loadcell
support, almost half of
the material yield
strength. Additional
ribs at the joint will
make this support
more safer.

15. Appendix 2- Safety factor distribution of silo structure
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Overall safety factor is
high with maximum
65. The lowest is 3.9
located where the
loadcell attached.
Adding more ribs will
increase the safety at
this location.

16. Appendix 2- Critical safety factor distribution of silo structure
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A close zoom
showing the area
where its safety
factor in the range
3.9 to 10.

17. Appendix 2- Displacement distribution of silo structure
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Stee structure
displacement is in
the range of yield
strength. Maximum
displacement is 1.36
mm at the top
section of structure.

18. Appendix 2 - Magnified zoom on high displacement on silo
structure
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A closer zoom showing
the are where structure
displament is high ( 1.3
mm).

19. Appendix 2- Elongation distribution of silo structure
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Elongation is one of
the critical properties of
material before it
reaches ultimate point.
The ultimate point
material mostly at 0.2%
elongation. Based on
the simulation,
maximum elongation
here is 0.028% located
at silo loadcell support.

20. Appedix 2-Magnified elongation of silo structure
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A closer look on
maximum elongation
of steel structure.

21. Appendix 3- On site erection method
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After foundation mature and
the pile cap strength has been
measured and meet quality
with strength 250 kgf/cm2 then
raise 3 main coloumb of the H
beam 300 x 300 and then joint
them with bracing per design
as shown at left picture
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22. Appendix 3- On site erection method
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Weld the silo main body
(circular shell ) directly at the
center of silo structure. Raise
the finished shell and then joint
with next circular shell. To
supper this activity, a hoist at
top side of coulomb is needed.
The welding shall follow the
American Standard or
Indonesian standard . Welding
shall be performed V but joint
both inside and outside of
circular shell.
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23. Appendix 3- On site erection method
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As shown, almost finish shell
joint of silo. At this stage
careful must be provided to
ensure the shell will not
collapse to other side. .
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24. Appendix 3- On site erection method
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The final stage of joint has
been reached. Add circular ring
to increase the strength of joint
between adjacent shell. Also all
bracing at 4 columns has been
welded.
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25. Appendix 3 - On site erection method
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At shown, the final stage has been reached. The
silo straightness must be measured and its contact
joint for load cell must be lock securely. Next step
will be installing the screw conveyors, filters and
pressure relief valve
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26. Appendix 3- On site erection method
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Silo now in finishing stage, as
shown far left pictures
complete with maintenance
deck.
The pictures at the right is load
cell with jacking housing for
easy maintenance, this image
was taken after 2 years in
service, due to close to sea the
rusty is growing faster. Need
repainting with marine
application on structure to
reduce the rusty.
At bottom side is contact joint
of load cell .

27. References
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1. Solidworks 2016, Linear stress analysis, viewed 4 October 2016,
http://www.solidworks.com/sw/products/simulation/stress-analysis.htm
2. Marklew, CM. Silo weighing. Bulk 96 design seminar.
3. Carson, J.W., Jenkyn,R.T. Load development and structural consideration in silo
design. Reliable flow of particulate solid II, August 1993
4. Scale manufacturer assosication, Loadcell application and test guideline, Ohio 2010

28. THANK YOU !
You can reach the autor at below :
chandr4_mnk@yahoo.com
chandramanik777@gmail.com
About the author :
Graduated from Mechanical Engineering Faculty of
Institute Technology of Bandung (ITB). At final year of
education focusing on fluid mechanic topic related to
Kaplan turbine performance, laminar and turbulent flow
in piping, positive displacement compressor and wind
turbine design. Finally choosing the topic on design of
centrifugal pump by utilizing Computational Fluid
Dynamic-Fluent as thesis for final exam.
More than 12 years experiences in various disciplines of
Engineering covering : Project Management, New
product development, Operation Management,
Continuous Development, Machine Maintenance.
Have been working in Global company such as :
SANYO Indonesia, KSB Indonesia and Monier
International membership for Project Management
Institute (www.pmi.org) . Manufacturing Engineering
Society ( www.sme.org) . American Society for Quality
(www.asq.org) .
Build a 40 tones cement silo at narrow
space
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