Changes in geotechnical engineering over the past 6000 years were summarized. Key changes included the development of specialized contractors for soil nails and ground anchors in the 1960s, and deep excavation projects in built-up urban areas. Major infrastructure projects in Singapore like the Kallang-Paya Lebar Expressway tunnel introduced complex construction methods near existing structures. Advances in soil investigation technology, analysis methods, and public expectations of safety following incidents have impacted the field. Looking ahead, projects will likely involve deeper excavations and more complex designs integrated across disciplines. Facing changes requires learning from others, mistakes, and a passion for continuous improvement.

1. CHANGES IN GEOTECHNICAL ENGINEERING
Chua Tong Seng
Managing Director, Kiso-Jiban Singapore Pte Ltd
GeoSS

2. CHANGES IN SINGAPORE
6000 year ago
Pre-Jurassic age
2013 - Future1960

3. Root of Trees: Geotechnical Engineering

4. CHANGES IN CAREER PATH
Knowledge & Happiness

5. Specialist Contractor
Soil Nails & Ground anchors Ground anchor and soil nails

6. Deep Excavation in Built-up Area

7. Geotechnical Consultant
Supervision & Analysis of KPE, Kallang Paya Lebar Expressway
Longest road tunnel in Singapore & South East Asia

8. KPE, Kallang Paya Lebar Expressway
One of the toughest projects in the world, The Straits Times, 2004

9. KPE Tunnel & Pelton Canal
36 ~ 55 m
10 m
5 m
~ 6 m
Song,2006
South Bound North Bound
18 – 27m canal

10. Blk
125
Blk
126
Blk
122
Blk
121
70m
Near Existing Structures & Tight Corridor
Chan,2006

11. HDB
Blk
HDB
Blk
Soft Soil
Old Alluvium
1m thick D/ Walls
South BoundNorth Bound
1m thick Cross-Wall using
Diaphragm Panel (7m c/c)0.8m thick Center D/ Wall
Sheet Pile + soldier piles
1.4m thick D/ Walls
Bored Pile
Soft Soil
Chan,2006
Cross Section
~RL70
~RL103

12. Blk
122
Blk
125 Construction of
Southbound Tunnel
Half Box Construction
First Stage
Song,2006
Cross-Wall @7m c/c

13. Blk
122
Blk
125
Excavation up to
formation level
(with Strutting System)
Half Box Construction
Second Stage
Song,2006
Completed tunnel

14. 2- Stage Construction (Half-box)
First Stage excavation: SB Second stage excavation: NB
SB
SB
NBSB

15. Construction is Imperfect (No Change)
• need to factor construction imperfection in
design
• close supervision together with finer
understanding of the geotechnical behaviour
through Analysis is important

16. Geotechnical Consultant
LTA, Circle Line Project, PPJ Station
North D-wall Construction Top Deck Slab Construction
P24

17. Cross-wall Section
Cross wall

18. Layout Plan
P20 P25P21 P22 P23 P24

19. Site Inspection of Cross-wall

20. UNIQUE METHODS

21. Across the Causeway: JB,Malaysia

22. Further North: Kuala Lumpur Limestone

23. Oversea Project: Philippine
25m

24. Middle East Project: Saudi Arabia

25. Features of Coralline Limestone

26. MEETING PEOPLE
Kepple Land International Limited
Keppel AlNumu Development Ltd
(A Keppel Land – SEDCO Joint Venture)
Saudi Diyar Consultants
Kiso-Jiban Consultants Co Ltd

27. CHANGES IN TECHNOLOGY
Some Observed Trends

28. Ground Anchors
60 T 150T

29. Reclamation
Method of Placing and Type of Materials

30. Shore Protection
Shallow: Armour Rocks Deeper: Caisson

31. Pile Load Testing
Anchors, Kentledge, Reaction Frame, Rapid Load Test, Proof Coring

32. SOIL INVESTIGATION
Borehole Image Processor, BIP
interesting and game changing

33. CHANGES IN METHOD OF ANALYSIS
Trends toward “finding the full picture myself”
2-D 3-DEmpirical
• i.e. Terzaghi
& Peck, 1967
• Based on
“what others
tell you”

34. Building Information Modeling, BIM
in Geotechnical Works
BIM, 4-D (time dimension) Holistic Approach including Analysis & Design

35. CHANGES IN LAWS & PUBLIC
EXPECTATION
Intersecting Trends

36. Impact of Nicoll Highway Collapse
Site photo KY Yong & SL Lee, 2008

37. Changes in Building Control (Amendment) Act 2007
• Any projects that involved:
• Deep excavation for depth >6m
• Foundations for buildings more than 30 storey
• Bored tunnel with diameter more than 2m
• Slope with height more than 6m
Require specialist PE(Geo) and specialist AC(Geo)
• New definition of Temporary buildings
• Does not include any earth retaining structure
• Temporary Works and Permanent Works are treated with
the same level of importance

38. Role of Specialist PE(Geo) and AC(Geo)
Building Control (Amendment No.2) Regulations 2008
• Specialist Professional Engineer (Geo)
– Determine the SI, namely type, extent (which shall include
quantity, layout, and depth) method of sampling, coring and
laboratory test results for the design and construction of earth
retaining structure including earth slope;
– Analyse the SI results and determine the geotechnical parameters
for the design of the earth retaining structure including
consideration of onerous water conditions, seepage pressures and
surcharge, earth, water, construction and accidental loadings;
– Determine and adopt appropriate method or model for the
analysis and design including the consideration of drained,
undrained and consolidation analyses, and appropriate drainage
conditions;
– Determine suitability of earth retaining structure types and
scheme, and the method and sequence of construction;
– Analyse the stability of the excavation work, taking into
consideration ground water, drainage and seepage conditions,
basal heave, hydraulic uplift and piping, and determine the ground
stabilisation or improvement works as appropriate;
– Determine allowable limits of ground deformation and changes in
ground water and piezometric levels, and measures to control
groundwater where required;
– Design tie-backs, soil or rock reinforcement, where applicable,
including the consideration of the structural and geotechnical
capacity;
– Ensure that drawings of the earth retaining structure, including
earth slope, are consist with the calculation relating to the
geotechnical aspects;
– Determine the instrumentation and monitoring of geotechnical
engineering parameters such as pore pressure, water table levels,
ground deformation and stresses including the consideration of
location, type and number of instruments, and frequency of
monitoring and reporting; and
– Assess monitoring results and sit condition to ensure that the
geotechnical aspects during construction are within design
assumptions and parameters at every critical stage of construction
and review or modify the design so as to ensure its adequacy as
appropriate.
• Specialist Accredited Checker AC (Geo)
– Review the adequacy of the SI, namely type, extent (which shall
include quantity, location and depth) and laboratory tests results
relating to the design and construction of the earth retaining
structure (inc earth slopes);
– Review SI results and the geotechnical parameters for the design
of the earth retaining structures, including consideration of
onerous water conditions, seepage pressures, surcharge, earth,
water, construction and accidental loadings;
– Review the method or model adopted for analysis and design,
including the consideration of drained, undrained and
consolidation analyses, and appropriate drainage conditions;
– Review suitability of earth retaining structure types and scheme,
and the method and sequence of construction to be applied;
– Review the stability of the excavation work, taking into
consideration groundwater, drainage and seepage conditions,
basal heave, hydraulic uplift and piping, and any ground
stabilisation or improvement works as appropriate;
– Review allowable limit of ground deformation and changes in
groundwater and piezometric levels, and measures to control
groundwater where required;
– Review the design of tie-backs, soil or rock reinforcement, where
applicable, including the consideration of the structural and
geotechnical capacity;
– Review the instrumentation and monitoring of geotechnical
engineering parameters (such as pore pressure, water table levels,
ground deformation and stresses) including the consideration of
location, type and number of instruments, and frequency of
monitoring and reporting;
– Review instrumentation and monitoring results and performance
of the earth retaining structure (including any earth slope), and
ground condition at the site to ensure tat there is no inadequacy in
the geotechnical aspects during the construction if carried out in
accordance with the plans of the underground buildings works;
and
– Review the adequacy of the founding or penetration depth of any
embedded earth retaining wall

39. WHAT LIES AHEAD OF US?
Inspirations to keep Spirit Up

40. Public Housing Project
12 &25 storey More than 40 storey

41. “Interaction and Iteration” to Integration
Plaxis 3D Foundation V2 ETABS V9.7
Initial spring constant
Loadings
Springs

42. Infrastructure Projects more Complex
Typical depth = 20-25m Deeper
Wen,2012

43. CHANGES IN TRADITIONS /
CUSTOMS

44. CHANGES IN HABITS
Plaxis Colour
Coding to
Improve
Productivity
and Efficiency
(QP,AC & BCA)

45. CHANGES IN PILING PRACTICES
Large Diameter
Piles with Bell-out

46. HOW DO WE COPE WITH
CHANGES?
Learn from Others

47. LEARN FROM MISTAKE
“Engineers shall hold
paramount the safety,
health and welfare of
the Public”, …
Prof R. Gilbert, USA

48. GeoSS-BCA Hong Kong Educational Visit
18-21 March 2012
• GeoSS
• BCA
• HDB
• Consultants
• Piling Specialists

49. GeoSS-BCA Taiwan Industry Learning Trip
17-20 March 2013

50. Passion, Passion, Passion
for things you do

51. Passionate about your Profession / Society
GeoSS-BCA-TGS, Taiwan, 2013 5YGEC, Japan, 2012

52. Empowering the Youth, SYGeoSS
• Founded on 25 May 2012
– Cham Wee Meng (Chairman)
– Lim Shiyi (Vice Chairman)
– Michelle Lew (Secretary)
– Dr. Yang Haibo (Treasurer)
– Goh Kok Hun
– Edward Koh Cho Meng
– Zhang Yunho
– Tran Vu Quoc

53. FACE THE CHANGES TOGETHER
Thank you
SYGeoSS Alumni Industry GeoSS
GeoSS