Effects of tunnel construction on nearby pile foundations 4

Columns Piled-raft Dragload Super-structure Downdrag Tunnelling in progress Pile cap Soil movement Dragload Resisting force (a) Lateral deflection (b) Piles Figure 1.1 An illustration of pile responses caused by tunnel construction (a) Tunnelling under pile foundation (b) Tunnelling adjacent to pile foundation Angel Underground Station, London MRT North-East Line C704, Singapore MTR Island Line, Hong Kong MRTA Subway, Bangkok Electric Power Tunnel, Japan Existing superstructure Tunnel Type 45 o Type Type Type MRT Circle Line C825, Singapore Cable Tunnel, London Tokyo Subway Line 7, Japan North/South Metroline, Amsterdam Jubilee Line Extension, London Channel Tunnel Rail Link 2, London MRT Circle Line C825, Singapore Figure 1.2 Relative tunnel-pile configurations observed in practice 177 Current design and assessment approach for pile responses subjected to tunnelling Indirect method Direct method 2-stage approach Unified approach Design charts * Chen et al. (1999) * Chen et al. (2000) Soil-spring method * Broms & Pandey (1987) * Sawatparnich & Kulhawy (2004) * Kitiyodom et al. (2004) 2-D finite element method * Vermeer & Bonnier (1991) * Lee et al. (1994) Boundary element method * Chen et al. (1999) 3-D finite element method * Mroueh & Shahrour (2002) * Lee & Ng (2005) * Cheng et al. (2004) * Chissolucombe et al. (2005) Finite element method * Surjadinata et al. (2005) Empirical method Risk of damage assessment * Mair et al. (1996) Pile settlement assessment * Jacobsz et al. (2005) Pile over-stress assessment * Jacobsz et al. (2005) Pile bearing capacity due to face pressure * Nakajima et al. (1992) * Inose et al. (1992) Pile bearing capacity due to tail void grouting * Nakajima et al. (1992) Figure 1.3 Current design and assessment approach for pile responses subjected to tunneling Figure 1.4 Zone of work restriction in Japan (Fujita, 1989) 178 (a) (b) Figure 2.1 Tunnelling adjacent to pile foundation in Singapore (a) MRT NEL Contract C704 (Coutts & Wang, 2000) (b) MRT NEL Contract C705 (Tham & Deustcher, 2000) Completely weathered granite Figure 2.2 MTR Island Line in Hong Kong (Forth & Thorley, 1996) 179 Figure 2.3 Angel Underground Development in London (Mair, 1993; Lee et al., 1994) (a) (b) Figure 2.4 Tunnelling for the Jubilee Line Extension in London (a) Under building (Powderham et al., 1999) (b) Adjacent to building (Selemetas et al., 2002) 180 (a) (b) (c) Figure 2.5 Tunnelling for the Channel Tunnel Rail Link (a) Renwick Road bridge (b) Ripple Road Flyover (c) A406 viaduct (Jacobsz et al., 2005) 181 Figure 2.6 Tunnelling adjacent to bridge pier in Japan (Moroto et al., 1995) Figure 2.7 Tunnelling under various constraints from pile foundations (Nakajima et al., 1992) 182 [Unit: meter] Figure 2.8 Tunnelling under large dome stadium supported by pile foundations (Inose et al., 1992) 18,000 2,500 13,000 2,500 7,100 3,400 29,000 Abutment A1 for HigashiShinagawa Bridge Figure 2.9 Tunnelling under pile foundations (Takahashi et al., 2004) 183 Figure 2.10 1-g model set up to simulate tunnelling effect on pile foundation (Morton & King, 1979) Figure 2.11 Centrifuge test set up to simulate tunnelling effect on pile foundation (Hergarden et al., 1996) 184 2i 2i D C B A B C D 15° 45° Piles that underwent "large" settlements Piles that underwent "small" settlements Area where "large" settlements might be expected Figure 2.12 Zone of influence around tunnel in which potential for large pile settlement exists (Jacobsz et al., 2002) (a) (b) Figure 2.13 Load transfer mechanism for (a) long pile (b) mid-length pile (Lee & Chiang, 2004) 185 (a) Legend: Zone A: Pile head settlement > Soil surface settlement Zone B: Pile head settlement = Soil surface settlement Zone C: Pile head settlement < Soil surface settlement (b) Figure 2.14 Pilot test carried out at Second Heinenoord tunnel site (a) Test layout (b) Zone of influence (Kaalberg et al., 2005) 186 350 E pile =28GPa, G max /P'=800, V L =1.8% Pile lateral deflection 300 250 Single pile 1-row pile (S1=3D) 1-row pile (S1=5D) 200 150 2D response = 3D response 0.14 50 0.10 100 0.07 Response of 2D to 3D analysis (%) L p /H=3.0, X pile =5.45m, D pile =1.2m, 0.0 0.1 0.2 0.3 0.4 0.5 Pile stiffness ratio, Ewall(2D) / Epile(3D) (a) 350 E pile =28GPa, G max /P'=800, V L =1.8% Pile head settlement 300 Single pile 1-row pile group (S1=3D) 1-row pile group (S1=5D) 250 200 150 2D response = 3D response 0.25 50 0.15 100 0.12 Response of 2D to 3D analysis (%) L p /H=3.0, X pile =5.45m, D pile =1.2m, 0.0 0.1 0.2 0.3 0.4 0.5 Pile stiffness ratio, Ewall(2D) / Epile(3D) (b) Figure 6.28 Influence of pile spacing on pile stiffness ratio (a) pile lateral deflection (b) pile head settlement 307 350 2-row PG (Pile 1) - S1=S2=3D 2-row PG (Pile 2) - S1=S2=3D 2-row PG (Pile 1) - S1=S2=5D 2-row PG (Pile 2) - S1=S2=5D L p /H=3.0, X pile =5.45m, D pile =1.2m, 250 E pile =28GPa, G max /P'=800, V L =1.8% Pile lateral deflection 200 150 2D response = 3D response 100 0.25 50 0.10 Response of 2D to 3D analysis (%) 300 0.0 0.1 0.2 0.3 0.4 0.5 Pile stiffness ratio, Ewall(2D) / Epile(3D) (a) 350 2-row PG 2-row PG 2-row PG 2-row PG L p /H=3.0, X pile =5.45m, D pile =1.2m, 250 E pile =28GPa, G max /P'=800, V L =1.8% Pile head settlement 200 150 2D response = 3D response 50 0.25 100 0.14 Response of 2D to 3D analysis (%) 300 (Pile 1) - S1=S2=3D (Pile 2) - S1=S2=3D (Pile 1) - S1=S2=5D (Pile 2) - S1=S2=5D 0.0 0.1 0.2 0.3 0.4 0.5 Pile stiffness ratio, Ewall(2D) / Epile(3D) (b) Figure 6.29 Influence of pile rows spacing on pile stiffness modification factor (a) Pile maximum horizontal deflection (b) Pile head settlement 308 Tunnel location Tunnel location Tunnel location x N pile group P1 1x1 P1 1x2 P1 Tunnel location 1x4 P1 x infinity Figure 6.30 Illustration of different pile group size represented by a 2-D mesh 309 x N pile group Tunnel location P1 P2 P1 P2 Tunnel location 2x2 P1 1x1 Tunnel location Tunnel location 2x1 P1 P2 P1 1x2 Tunnel location Tunnel location x N pile group P1 P1 1x4 P2 x infinity Tunnel location Tunnel location 2x4 P1 x infinity (a) Pile stiffness modification factor 0.35 Pile head sett. (2xN pile group) - Pile Pile max. lat. defl. (2xN pile group) - Pile Pile head sett. (1xN pile group) - Pile Pile max. lat. defl. (1xN pile group) - Pile 0.30 0.25 0.20 0.15 0.10 0.05 0.00 10 No. of piles, N (b) Figure 6.31 Variation of pile group size on pile stiffness modification factor (a) Pile group types (b) Modification factor 310 W/O pilecap (Pile 1) W/O pilecap (Pile 2) With pilecap (Pile 1) With pilecap (Pile 2) 300 250 D pile = 1.2m, E pile = 28GPa G max /P' = 800, V L = 1.81% 2x2 pile group Pile lateral deflection 200 150 2D response = 3D response 100 0.?? 50 0.08 Response of 2D to 3D analysis (%) 350 0.0 0.1 0.2 0.3 0.4 0.5 Pile stiffness ratio, Ewall(2D) / Epile(3D) (a) 250 E pile =28GPa, G max /P'=800, V L =1.8% Pile head settlement, 2x2 pile group 200 W/O pilecap W/O pilecap With pilecap With pilecap 150 (Pile 1) (Pile 2) (Pile 1) (Pile 2) 100 2D response = 3D response 0.29 50 0.18 Response of 2D to 3D analysis (%) L p /H=3.0, X pile =5.45m, D pile =1.2m, 0.0 0.1 0.2 0.3 0.4 0.5 Pile stiffness ratio, Ewall(2D) / Epile(3D) (b) Figure 6.32 Influence of pile cap on pile stiffness modification factor (a) Pile maximum horizontal deflection (a) Pile head settlement 311 0.20 max. horiz. defl. (Xpile=5.45m) E pile =Pile 28GPa Pile stiffness modification factor G max /P' = 400 V L = 1% 0.15 X pile /D tun = 1.5 L pile /H= 3.0 X pile /D tun = 0.8 L pile /H= 3.0 0.10 X pile /D tun = 1.5 L pile /H= 3.0 0.05 X pile /D tun = 0.8 L pile /H= 3.0 Pile head settlement Pile lateral deflection 0.00 0.0 0.5 1.0 1.5 Pile diameter, Dpile 2.0 2.5 (a) 0.20 E pile = Pile 28GPa max. horiz. defl. (Xpile=5.45m) Pile stiffness modification factor G max /P' = 400 X pile /D tun = 1.5 L pile /H= 3.0 V L = 4% 0.15 X pile /D tun = 0.8 L pile /H= 3.0 Pile head settlement 0.10 X pile /D tun = 1.5 L pile /H= 3.0 0.05 X pile /D tun = 0.8 L pile /H= 3.0 Pile lateral deflection 0.00 0.0 0.5 1.0 1.5 Pile diameter, Dpile 2.0 2.5 (b) Figure 6.33 Pile stiffness modification factor for Condition with (a) VL=1% (b) VL=4% 312 Response of 2D to 3D analysis (%) 150 Xpile=5.45m, Xpile=5.45m, Xpile=9.75m, Xpile=9.75m, Dpile=1.2m Dpile=0.3m Dpile=1.2m Dpile=0.3m 2D response = 3D response 100 50 70% to 120% L p /H=0.5, X pile =varying, D pile =varying, E pile =28GPa, G max /P'=400, V L =1%, Pile max. lateral deflection 0.00 0.20 0.40 0.60 0.80 1.00 1.20 Pile stiffness ratio, Ewall(2D) / Epile(3D) (a) Response of 2D to 3D analysis (%) 150 Xpile=5.45m, Xpile=5.45m, Xpile=9.75m, Xpile=9.75m, Dpile=1.2m Dpile=0.3m Dpile=1.2m Dpile=0.3m 2D response = 3D response 100 50 55% to 95% L p /H=0.5, X pile =varying, D pile =varying, E pile =28GPa, G max /P'=400, V L =1%, Pile head settlement 0.00 0.20 0.40 0.60 0.80 1.00 1.20 Pile stiffness ratio, Ewall(2D) / Epile(3D) (b) Figure 6.34 Convergence in Condition with Lp/H=0.5 (a) Pile maximum horizontal deflection (b) Pile head settlement 313 0.10 9.75m, 1% E pile = 28GPa 5.45m, 1% Pile stiffness modification factor G max /P' = 400 0.08 L p /H = 1.0 0.06 X pile /D tun = 1.5, V L =4% X pile /D tun = 1.5, V L =1% 0.04 X pile /D tun = 0.8, V L =1% X pile /D tun = 0.8, V L =4% 0.02 0.00 0.0 0.5 1.0 1.5 2.0 2.5 Pile diameter, Dpile (a) Xpile=5.45m, VL=4% 0.10 X pile /D tun = 1.5, V L =4% E pile = 28GPa X pile /D tun = 1.5, V L =1% Pile stiffness modification factor G max /P' = 400 0.08 L p /H = 3.0 X pile /D tun = 0.8, V L =1% 0.06 0.04 0.02 X pile /D tun = 0.8 , V L =4% 0.00 0.0 0.5 1.0 1.5 Pile diameter, Dpile 2.0 2.5 (b) Figure 6.35 Calibration charts for Condition with (a) Lp/H=1.0 (b) Lp/H=3.0 314 4.0 E pile = 28GPa Pile stiffness modification factor 3.5 G max /P' = 400 Overall 3.0 X pile /D tun = 1.5 & 0.8 L pile /H= 3.0, V L =1% 2.5 2.0 X pile /D tun = 1.5 L pile /H= 3.0, V L =4% 1.5 X pile /D tun = 0.8 L pile /H= 3.0, V L =4% 1.0 0.5 Xpile=5.45m, VL=4% 0.0 0.0 0.5 1.0 1.5 Pile diameter, Dpile 2.0 2.5 Figure 6.36 Calibration charts for Condition with Lp/H=3.0 315 0.50 E pile = 28GPa 0.45 Pile stiffness modification factor G max /P' = 400 0.40 L p /H = 1.0 0.35 0.30 0.25 0.20 X pile /D tun = 1.5, V L = 1% 0.15 X pile /D tun = 1.5, V L = 1% 0.10 X pile /D tun = 0.8, V L = 1% 0.05 X pile /D tun = 0.8, V L = 4% Xpile=5.45m, VL=1%, 0.00 0.0 0.5 1.0 1.5 Pile diameter, Dpile 2.0 2.5 (a) 0.50 E pile = 28GPa Pile stiffness modification factor 0.45 G max /P' = 400 0.40 L p /H = 3.0 0.35 0.30 0.25 X pile /D tun = 0.8 & 1.5, V L = 1% & 4% 0.20 0.15 0.10 0.05 Xpile=5.45m, VL=4% 0.00 0.0 0.5 1.0 1.5 Pile diameter, Dpile 2.0 2.5 (b) Figure 6.37 Calibration charts for Condition (a) Lp/H=1.0 (b) Lp/H=3.0 316 4.00 E pile = 28GPa Pile stiffness modification factor 3.50 X pile /D tun =1.5, L pile /H= 3.0, V L = 1% G max /P' = 400 Overall 3.00 X pile /D tun =1.5, L pile /H= 3.0, V L = 4% 2.50 X pile /D tun =0.8. L pile /H= 3.0, V L = 1% 2.00 X pile /D tun =0.8, L pile /H= 3.0, V L = 4% 1.50 1.00 0.50 Xpile=5.45m, VL=4% 0.00 0.0 0.5 1.0 1.5 2.0 2.5 Pile diameter, Dpile Figure 6.38 Calibration charts for Condition with Lp/H=3.0 317 Xpile=5.45m, VL=4% 0.10 X pile /D tun = 1.5, V L =4% E pile = 28GPa X pile /D tun = 1.5, V L =1% Pile stiffness modification factor G max /P' = 400 0.08 L p /H = 3.0 X pile /D tun = 0.8, V L =1% 0.06 0.04 0.02 X pile /D tun = 0.8 , V L =4% 0.00 0.0 0.5 1.0 1.5 Pile diameter, Dpile 2.0 2.5 (a) 0.50 E pile = 28GPa 0.45 Pile stiffness modification factor G max /P' = 400 0.40 L p /H = 3.0 0.35 0.30 0.25 X pile /D tun = 0.8 & 1.5, V L = 1% & 4% 0.20 0.15 0.10 0.05 Xpile=5.45m, VL=4% 0.00 0.0 0.5 1.0 1.5 Pile diameter, Dpile 2.0 2.5 (b) Figure 6.39 Calibration charts and modification factors for MRT NEL C704 Pier 20 (a) Condition (b) Condition 318 Distance from SB tunnel axis (m) 20 30 40 50 10 60 70 -5 Surface settlement (mm) SB -10 -15 -20 2-D FE - Greenfield Measured -25 (a) Pile settlement (mm) Pile lateral deflection (mm) -2 -4 -6 -8 -10 -2 -4 -6 -10 10 10 20 20 Tunnel springline Tunnel springline Pier 20 30 P2 P1 40 Depth (m.b.g.l.) Pier 20 Depth (m.b.g.l.) -8 30 P2 P1 40 SB SB 50 50 60 60 Pile P1: 2-D factor = 0.075 2-D factor = 0.200 Pile P2: 2-D factor = 0.075 2-D factor = 0.200 Pile P1: 2-D factor = 0.075 2-D factor = 0.200 Pile P2: 2-D factor = 0.075 2-D factor = 0.200 70 70 (b) (c) Figure 6.40 Results of 2-D finite element analysis (a) Greenfield soil movement (b) Pile horizontal deflection (c) Pile settlement 319 Bending moment, Mxx (KNm) -500 -300 -100 100 Bending moment, Mxx (KNm) 300 500 -500 -300 -100 10 10 20 500 20 30 Depth (m.b.g.l.) Depth (m.b.g.l.) 300 Tunnel springline Tunnel springline Pier 20 40 P2 100 30 Pier 20 P2 P1 40 P1 50 50 SB SB 60 60 Measured - Pile P1 2-D factor = 0.075 2-D factor = 0.200 Measured - Pile P2 2-D factor = 0.075 2-D factor = 0.200 70 70 (a) (b) Figure 6.41 Comparison between predicted and measured pile bending moment (a) Front pile (b) Rear pile Bending moment, Mxx (KNm) -500 -300 -100 100 300 500 10 20 Depth (m.b.g.l.) Tunnel springline 30 Pier 20 P2 P1 40 SB 50 Measured - Pile P1 60 chart assuming single pile) 2-D factor = 0.075 (from 2-D factor = 0.200 (from chart assuming pile group 2-D factor = 0.262 (Equivalent EA assuming pile group) 2-D factor = 0.707 (Equivalent EI assuming single pile) 2-D factor = 0.943 (Equivalent EA assuming single pile) 70 Figure 6.42 Comparison of bending moment from equivalent pile stiffness method and calibration charts 320 Figure 6.43 Tunnelling under the link structure between Pan Pacific Hotel and Marina Square Figure 6.44 2-D finite element mesh adopted to simulate the link structure in MRT CCL1 C825 321 10 Distance from tunnel axis (m) 20 30 40 50 60 2.0 1.0 Surface settlement (mm) 0.0 -1.0 -2.0 NB -3.0 SB -4.0 -5.0 -6.0 -7.0 -8.0 SB+NB (with LL) - 2D Factor=0.036 SB+NB (with LL) - 2D Factor=1.00 SB+NB (with LL) - 2D Factor=3.57 Measured column settlement Etun=0.1GPa , -S2 Filename: CASE2G2B.RPT Figure 6.45 Comparison between predicted and measured building settlement 322 [...]... - Pile P2 41 6 (Long term 1) - Pile P2 46 5 (Long term 2) - Pile P2 Day Day Day Day 30 55 (SB) - Pile P2 1 04 (SB+NB) - Pile P2 41 6 (Long term 1) - Pile P2 46 5 (Long term 2) - Pile P2 35 (a) (b) Figure 3.25 Effect of post-tunnelling loading on the bending moment response of pile P2 (a) transverse direction (b) longitudinal direction -10000 SG 640 1- 640 4 - SB SG 640 9- 641 2 - SB SG 641 7- 642 0 - SB SG 642 5- 642 8... SG 642 5- 642 8 - SB SG 640 1- 640 4 - NB SG 640 9- 641 2 - NB SG 641 7- 642 0 - NB SG 642 5- 642 8 - NB -9000 Axial force in pile (kN) -8000 -7000 SB tunnel -6000 SG 640 5- 640 8 - SB SG 641 3- 641 6 - SB SG 642 1- 642 4 - SB SG 642 9- 643 2 - SB SG 640 5- 640 8 - NB SG 641 3- 641 6 - NB SG 642 1- 642 4 - NB SG 642 9- 643 2 - NB NB tunnel -5000 -40 00 -3000 -2000 -1000 0 0.0 0.5 1.0 1.5 2.0 Volume loss (%) 2.5 3.0 Figure 3.26 Development of axial force with...Zone A Zone C Zone B Zone B Zone C Legend: Zone A: Pile head settlement > Soil surface settlement Zone B: Pile head settlement = Soil surface settlement Zone C: Pile head settlement < Soil surface settlement Figure 2.15 Zone of influence around EPB tunnel in London Clay (Selemetas et al., 2005) 187 Check on pile settlement (Jacobsz et al., 2005) End bearing pile Friction pile Assumptions: 1)... Figure 2.18 Observations of pile responses (a) Pile head settlement (b) Pile maximum axial force (c) Pile maximum lateral deflection (d) Pile maximum bending moment 191 Contract 7 04 Serangoon Station Woodleigh Station N LEGEND MRT NORTH-EAST LINE 0 1 2 3 km MRT STATION Figure 3.1 Location of the MRT North East Line in Singapore TUNNEL ADVANCING DIRECTION Pile foundation P10 P11 P12 P13 P 14 P15 P16 P17 P18... Day Day Day Day 1 04 (SB+NB) - Pile P1 41 6 (SB+NB+Loading 1) - Pile P1 46 5 (SB+NB+Loading 2) - Pile P1 41 6 (Net due to Loading 1) - Pile P1 46 5 (Net due to Loading 2) - Pile P1 35 30 Day Day Day Day Day 1 04 416 46 5 41 6 46 5 (SB+NB) - Pile P2 (SB+NB+Loading 1) - Pile P2 (SB+NB+Loading 2) - Pile P2 (Net due to Loading 1) - Pile P2 (Net due to Loading 2) - Pile P2 35 (a) (b) Figure 3. 24 Locked-in stress... dia pile - Front pile - Rear pile 1.5 2 (b) 0 100 200 300 40 0 500 0 0.5 Volume loss (%) 1 - Rear pile 1.2m dia pile - Front pile 1.5 2 (a) 0 500 1000 1500 2000 2500 0 0.2 0 .4 0.8 Volume loss (%) 0.6 - Rear pile 1.8m dia pile - Front pile 1 1.2 1 .4 (b) 211 Figure 3.30 Relationship between longitudinal bending moment and volume loss due to SB tunnel advancement (a) 1.2m diameter pile (b) 1.8m diameter pile. .. (SB) - Pile P1 1 04 days (SB+NB) - Pile P1 55 days (SB) - Pile P2 1 04 days (SB+NB) - Pile P2 35 30 55 days (SB) - Pile P1 1 04 days (SB+NB) - Pile P1 55 days (SB) - Pile P2 1 04 days (SB+NB) - Pile P2 35 (a) (b) Figure 3.19 Measured bending moment in piles P1 and P2 at Pier 20 (a) transverse direction (b) longitudinal direction 2 04 -25000 Cracking moment Axial load (kN) -ve compression, +ve tension -30000... Level 1 P4 NB Level 3 P4 NB Level 1 P3 NB Level 3 P3 NB 90 80 Pier 11 Stress relief in piles (%) Stress relief in piles (%) 80 Level 3 P6 SB Level 1 P5 SB Level 3 P5 SB Level 2 P6 NB Level 4 P6 NB Level 2 P5 NB Level 4 P5 NB 60 50 40 30 70 Level 2 P4 SB Level 4 P4 SB Level 2 P3 SB Level 4 P3 SB Level 2 P4 NB Level 4 P4 NB Level 2 P3 NB Level 4 P3 NB Pier 14 60 50 40 30 20 20 10 10 0 0 0 2 4 6 Days... (Cheng et al., 20 04) Dpile 9 Htun 8 Lp V L=1%, Xpile/Dtun=0.92 Dtun 200 Pile maximum bending moment (kNm) Pile maximum lateral deflection (mm) 1.5 & Dpile=0.8m 7 VL=1%, Xpile/Dtun=1 6 & Dpile=0.8m Xpile 5 4 3 2 Centrifuge tests (Loganathan, 1999) 1 V L=1%, Xpile/Dtun=1 & Dpile=0.8m VL=0.25%, 150 Xpile/Dtun=1 & Dpile=1m 100 50 VL=1%, Xpile/Dtun=0.92 & Dpile=0.8m 3-D FE (Cheng et al., 20 04) 0 0 0 0.5 1... (SG 641 7- 642 0) - A 16.7m (SG 642 1- 642 4) - B 21.7m (SG 642 5- 642 8) - C 26.7m (SG 642 9- 643 2) - D -100 -150 -200 -250 20 30 40 50 60 70 80 90 100 110 120 Time (Days) Figure 3.21 Development of longitudinal bending moment in pile P1 at Pier 20 206 -30000 -20000 -15000 -10000 Cracking moment Axial load (kN) -ve compression, +ve tension -25000 -5000 0 (a) 5000 -40 00 -3000 -2000 -1000 0 1000 2000 3000 40 00 Longitudinal . responses caused by tunnel construction (a) Tunnelling under pile foundation (b) Tunnelling adjacent to pile foundation Type 1 Type 3 Type 4 Type 2 Angel Underground Station, London MRT North-East. settlement Zone C: Pile head settlement < Soil surface settlement Zone A Zone B Zone B Zone C Zone C 188 Check on pile settlement (Jacobsz et al., 2005) End bearing pile Friction pile Assumptions: 1). for pile responses subjected to tunneling Figure 1 .4 Zone of work restriction in Japan (Fujita, 1989) 179 (a) (b) Figure 2.1 Tunnelling adjacent to pile foundation in