Post on 24-Mar-2018
Nobuyuki MATSUI, Manager (B. Eng.(Civil), MSc(Civil), Welding Engineer(JWES1)
Nippon Steel & Sumitomo Metal
Southeast Asia Pte. Ltd. ,Singapore
Technical solutions by
Hat-type Steel Sheet Piles
for enhancing safety and productivity in construction
Today’s Topics
1. Outline of Hat-type steel sheet piles
2. Design Consideration for sheet pile in Eurocode
3. 4 point bending test for Hat type sheet pile
4. Combined Sheet Pile using HAT type sheet Pile
Types of steel sheet Piles
・Effective width is 900mm
(Maximum in the world as rolled piles)
・Direction of piling are same
・Slender and effective section
■ Characteristic of Hat-type sheet piles
400
900
・Type Ⅲ
・NS-SP-10H
U type
Hat type
Benefit of applying Hat-type sheet Piles
1.Rapid construction - Installed combined pile which has 900mm width sheet pile
2.Reduction of steel weight of walls - Slender section and 100% full sectional performance
3.Utility for any requirements - Assorted section type and high applicability
1.Rapid construction - Installed combined pile which has 900mm width sheet pile
2.Reduction of steel weight of walls - Slender section and 100% full sectional performance
3.Utility for any requirements - Assorted section type and high applicability
HAT type sheet piles can make construction affordable
HAT type sheet piles can make construction affordable
U-type steel sheet pile
U-Type Sheet Pile -Conventional type-
Robust
15
900
368
17
900
370
10.8
900
230
13.2
900
300
Slender/Compact/Affordable
1) Effective width is 900mm, the widest rolled sheet pile in the world. 2) Reduce the number of sheet piles, construction period and cost.
Hat-type steel sheet pile
■ Hat-Type Steel Sheet Pile
HAT-Type
U-Type
45% number of piles reduction
10H 25H
45H 50H
Temporary wall Quay wall
Retaining wall
Application of Hat-type steel sheet piles
River Revetment
900mm
600mm
400mm
Hat Type(Hat900)[10H]
U-wide Type(U600)[Ⅱw]
U Type(U400)[Ⅱ]
Neutral axis of each piles and that of interlocked wall are equivalent
900mm
600mm
400mm
Hat Type(Hat900)[10H]
U-wide Type(U600)[Ⅱw]
U Type(U400)[Ⅱ]
Neutral axis of each piles and that of interlocked wall are equivalent
U-type wall transmits longitudinal shear force to adjacent piles at interlocks. If the shear
force is not transmitted properly due to slippage at interlocks, moment capacity of the wall
should be reduced and the wall deflection will increase.
Hat-type wall is not necessary to be considered this effects because the interlocks are
located on the outermost part of the wall where the shear force is negligible
900mm
600mm
400mm
Hat Type(Hat900)[10H]
U-wide Type(U600)[Ⅱw]
U Type(U400)[Ⅱ]
Neutral axis of each piles and that of interlocked wall are equivalent
900mm
600mm
400mm
Hat Type(Hat900)[10H]
U-wide Type(U600)[Ⅱw]
U Type(U400)[Ⅱ]
Neutral axis of each piles and that of interlocked wall are equivalent
Interlock integrity of sheet pile
y1
y0
ey
M
T
T
鋼矢板1枚での
中立軸
実際の中立軸
STATE A
Neutral axis
of practical wall Neutral axis
of pile
STATE B PRACTICAL STATE
Slip at Joint
Types of steel sheet piles in Eurocode
■ Eurocode 3 - Design of Steel Structures- Part 5: Piling
10
where :
Wel is the elastic section modulus determined for a continuous wall;
Wpl is the plastic section modulus determined for a continuous wall;
γM0 Partial safety factor (=1.0)
βB is a reduction factor that account for a possible lack of shear force
transmission in the interlocks.
βB = 1.0 for Z-piles and triple U-piles
βB ≤ 1.0 for single and double U-piles
Class 1 or 2 Class 3
c,Rd pl y M0BM W f 0c,Rd el y MBM W f
Design moment resistance in the Eurocode
Reduction factor for U-type sheet piles
11
where:
I is the second moment of area of the continuous wall
E is Young’s modulus
βD is to account for the possible reduction due to insufficient shear force
transmission in the interlock.
βD = 1.0 for Z-piles and triple U-piles
βD ≤ 1.0 for single and double U-piles
The numerical value for βB and βD are given in the National Annex.
eff DEI EI
Reduction factor for U-type sheet piles
Design effective flexural stiffness in the Eurocode
12
Type of U-pile unit
Number of structural
support levels
Reduction factor βB and βD
Highly unfavorable conditions
Unfavorable conditions
Favorable conditions
βB βD βB βD βB βD
Singles or uncrimped doubles
0 0.40 0.30 0.50 0.35 0.60 0.40
1 0.55 0.35 0.60 0.40 0.70 0.45
> 1 0.65 0.45 0.70 0.50 0.80 0.55
Crimped or welded doubles
0 0.70 0.60 0.75 0.65 0.80 0.70
1 0.80 0.70 0.85 0.75 0.95 0.80
> 1 0.90 0.80 0.95 0.85 1.00 0.90
Reduction factor for U-type sheet piles
Reduction factor for U-type sheet piles in the National Annex
13
Interlocks not treated with sealants or lubricants
• βB may be increased by 0.05 (to a maximum value of 1.0)
• βD may be increased by 0.05 (to a maximum value of 1.0)
Welding near the wall top
• βB may be increased by 0.1, 0.15 or 0.2 respectively for highly
unfavorable, unfavorable and favorable conditions ( to a maximum
value of 1.0)
• βD may be increased by 0.15, 0.2 or 0.25 respectively for highly
unfavorable, unfavorable and favorable conditions ( to a maximum
value of 1.0)
Reduction factor for U-type sheet piles
Countermeasures for enhancing the reduction factor
0
10000
20000
30000
40000
50000
60000
70000
80 120 160 200 240
Unit weight per 1m wall width (kg/m2)
10H
25H
ⅡⅢ
Ⅳ
ⅤL
Mo
me
nt
of
Iners
ia p
er
1m
wa
ll w
idth
(m3
/m)
45H
50H
Influence of interlock integrity
▽36%
▽34%
▽23% Joint efficiency
=0.6
Hat type sheet pile can be reduce the steel weight
Recommendation to Hat-type sheet piles
Similar with Z-type piles, for a wall using Hat-type steel piles, the
reduction factors are NOT required (βB = 1.0 , βD
= 1.0 ) because
interlocks are located at the most outer edge of the wall, which
means that the shear force does not occur in the interlocks.
• Place : Nanyang Technological University
(Supervised by Dr. Chiew Sing-Ping)
• Machinery : 100t Compression machine
• Specimen : Hat-type sheet pile (10H×2 piles)
(Manufactured in Japan)
• Measurement: Load, Displacement, Strain
Structural Test Plan (NTU in Singapore)
P/2
2300 1000 1000 2300
P/2
Type NS-SP-10H
Grade SYW295
Pile Length(m) 8
Moment of Inertia
(cm4/2piles)18,860
Section Modulus
(cm3/2piles)1,624
Material Yield Strength
(MPa)295
• Dimension
Behavior of Hat-type (NTU in Singapore)
• The flexural behavior exceeding yield strength could be verified.
• There is no evidence of any slippage at the interlock between
the 2 piles.
■ After the loading on the sheet piles
Interlocking position after
the loading
Bending Test Results (NTU in Singapore)
• Flexural rigidity in elastic range was equivalent to the theoretical one
• The section kept elastic by its calculated plastic load
0
100
200
300
400
500
600
700
800
0 50 100 150 200 250
Lo
ad
(kN
)
Vertical displacement at center(mm)
Theoritical Elastic line
Tested curve
NTU FEM(ABAQUS)
Pmax=694kN
Calculated Plastic Load
Calculated Yield Load
■ Load-Deflection behavior
0
50
100
150
200
250
-4000 -3000 -2000 -1000 0 1000 2000 3000 4000
strain at Center(μ)
201kN
402kN
601kN
Strain was distributed from above to bottom and the value become 0 at neutral line so the Navier hypothesis is applicable
■ Strain distribution along cross section at center
Neutral Line
Arrangement of strain gages
Bending Test Results (NTU in Singapore)
Additional concerns of sheet piles
Hat type sheet pile can be evaluated as Class2 section in Eurocode
• In case of Hat-type sheet pile
(for SYW295)
Sectional performance of Hat-type
1. It was verified that strength exceeded its design value
• Flexural rigidity in elastic range was equivalent to the theoretical one
• After the yielding, plastic behavior can be obtained without the decline of
strength by buckling
2. Hat type sheet pile can be expected 100% of its sectional
performance.
• There is no evidence of any slippage at the interlock between the 2 piles.
3. Based on above results, Hat-type sheet pile should be
considered its full sectional performance and evaluated as Class
2 in Eurocode
Other Hat-type sheet piles
Improvement Drainage in Singapore(Roselane)
■ Solutions for narrow working space
NS-SP-J
• NS-SP-J can minimize working space.
It can be unnecessary to relocate existing
structure such as residences.
• Interlock integrity can be treated as 100%
because the interlocks locates on outermost
H-beam
Steel sheet piles
Fillet welding
(partial)
(Hat-type)
New Application of Steel Pipe Pile(HAT+H)
- High stiffness sheet pile-
0
200
400
600
800
1000
1200
0.000 0.005 0.010 0.015
Be
nd
ing
Mo
me
nt
(kN
m)
Curvature (1/m)
Experimental Value
Calculated Value
Theoretical Yield Moment
High Stiffness & Effective Section
U-type
Hat + H
■ Moment of Inertia
Flexural Test
Neutral Axis
Neutral Axis of wall
Neutral Axis of pile
1) Composite Section Flexural Test Result
2) 100% Joint Efficiency
Numerous sectional properties
【1 Sheet pile & 1 H beam combined type】
■ Optimization of design 【2 Sheet pile & 1 H beam combined type】
Easy Fabrication in Construction Site
Fabrication manual
In Indonesia (2013)
In Singapore (2014)
In Indonesia (2013)
• 40-60% of Pile length expected to
be welded by Fillet Welding
• The Procedure can be referred to
Fabrication Manual by NSSMC
Type U-Type + Soldier Pile Hat+H
Outline
Spec. H beam section:UB610×229×243
U type steel sheet pile FSP-Ⅳ
HAT + H
10H + HY700×250×12×19
Unit weight 342kg/m(1.0) 256kg/m(0.7 : Z equivalent)
173kg/m(0.5 : I equivalent)
Installation 2 Piles InstalIation
Installed U-type and soldier pile
separately
1 Pile InstalIation Installed HAT and H
at the same time
Comparison with conventional walls
-Piling test-
Development for HAT+H in Singapore
-Publish technical papers-
Thank you very much
for your kind attention