1. Presented by L.M. Mak 1 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation THE HONG KONG UNIVERSITY OF SCIENCE & TECHNOLOGY Civil Engineering Department Civl 395 Project Implementation Objective: To implement a Project from start of a Project Feasibility Study until it is ready to call tenders. L. M. MAK 02/03/2007Foundation Design

2. Presented by L.M. Mak 2 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation Foundation A.Foundation Types –Dependent upon ground conditions, allowable bearing capacity, settlement –Imposed structural loads 1. Shallow Foundation - Footings 2. Deep Foundation - Piling

3. Presented by L.M. Mak 3 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation Previous Site Investigations (SITE B) From Data Bank of Civil Engineering Development Department (CEDD) -Previous Boreholes Location Plans * 262D, D6 & D7 * 1979 for Tuen Mun New Town Area 19 D27 D31 D6 262D D7 Site B (East) Site B (South)

4. Presented by L.M. Mak 4 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation Borehole Records D6

5. Presented by L.M. Mak 5 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation D6 +58 Depth (m) 0m  b =18kN/m 3 Top soil GWLN=100.45m  b =18kN/m 3 c’=2kPa  ’=30 o ColluviumN=34 N=96 N>2005.00m  b =20kN/m 3 c’=5kPa,  ’=35 o Completely Decomposed Siltstone 6.15m  b =21kN/m 3 c’=8kPa  ’=38 o Highly to Moderately Decomposed Matamorphised Siltstone TCR 94% 6.95m  b =23kN/m 3 c’=10kPa,  ’=45 o Moderately to Slightly Decomposed Matamorphised Siltstone TCR 82%~100% 9.96m  b =21kN/m 3 c’=8kPa,  ’=38 o Highly to Moderately Decomposed Matamorphised Siltstone TCR 54% 11.35m  b =23kN/m 3 c’=15kPa  ’=45 o Moderately Decomposed Matamorphised Siltstone TCR 75% 12.82m  b =24kN/m 3 c’=20kPa,  ’=45 o Slightly Decomposed Matamorphised Siltstone TCR 93%~100% 17.82m Summary of ground conditions

6. Presented by L.M. Mak 6 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation Foundation Options: Site B (East) I.Proposed School – 7 storey r.c. structure Imposed load – assumes 7@20kPa(storey) = 140kPa (i) Footings Consider footings – strip footings say 3mx6m, imposed load = 150x3x6 = 2,700kN Founding material (Depth: 0.5m onto Colluvium)

7. Presented by L.M. Mak 7 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation => From PNAP 141 Allowable Bearing Pressure for Colluvium = 200 kPa(Submerged) > 140 kPa (O.K.)

8. Presented by L.M. Mak 8 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation => From Geoguide 1 Figure A1 & A2 q ult =c’N c s c i c t c g c +0.5g’B’N g s g i g t g g g +q’N q s q i q t q g q From c’  ’ values to estimate q ult Allow Factor of Safety against general bearing capacity failure = 3 to obtain q allowable Compare with the imposed load of 150kPa to confirm => O.K.

9. Presented by L.M. Mak 9 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation 2. Induced Settlement => Total settlement  25mm => Differential settlement  1:300

10. Presented by L.M. Mak 10 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation ii) Piles =>Driven Piles - Capacity: Steel H Piles 305 x 305 x 180kg/m Grade 55C Carrying Capacity = 2950 kN For imposed load of 2000 kN Pile No. = 2700 / 2950 = 1 no

11. Presented by L.M. Mak 11 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation Foundation Options Options Technical Aspects Cost Aspects Programme Aspects 1. FootingStrip Footing Relatively Cheaper Relatively Shorter 2. Pile: a) Steel H Piles 1 no. @305x305x 180kg/m(55C) ? ? Recommendation : ?

12. Presented by L.M. Mak 12 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation II.Proposed High-rise building Imposed load 40storey, say 40@20kPa = 800kPa (i) Footings a.Strip footing on colluvium => O.K.?Bearing capacity failure? Excessive Settlement? b.Lower to CD siltstone at 5.00m depth => O.K.?+ Excavation/ Laterial support c.Further lower to H/MD siltstone at 6.15m

13. Presented by L.M. Mak 13 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation (ii) Pilings a. Steel H-piles Capacity : steel H-piles 305x305x198kg/m Grade 55C Carrying Capacity : 3140kN For imposed Load Assume imposed area 30x30m 2 Imposed load = 800kPa x 30 x 30m 2 = 720,000kN Pile No. = 720,000/3,140 = 230 Nos. Driven to refusal to H/M siltstone at about 6.5m depth

14. Presented by L.M. Mak 14 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation b. Bored Piles : Assume 1.5m  bored piles terminated at M/SD Siltstone at 11.50m depth (q a = 5,000kPa ) 1.5m  M/SD Siltstone q a = 5,000kPa Bearing capacity of pile =  D 2 /4 x 5000 = 8836kN For imposed load of 720,000kN, require 720,000/8836 = 82 Nos. How about wind load?

15. Presented by L.M. Mak 15 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation Foundation Options Options Technical Aspects Cost Aspects Programme Aspects 1. Footing i)Bearing Capacity Failure ii)Excessive settlement (technical not acceptable) Not considered further 2. Pile: a) Steel H Piles 230 nos. @305x305x 198kg/m(50c) ? ? b) Bored Piles 82 nos of 1.5m  ? ? Recommendation : ?

16. Presented by L.M. Mak 16 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation A A B B LAYOUT PLAN ( SITE B EAST ) Foundation for - Site B (East)

17. Presented by L.M. Mak 17 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation A A Proposed General Building Plan (Section A-A)

18. Presented by L.M. Mak 18 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation CARRY OUT SITE FORMATION (FOR RAFT FOOTING FOUNDATION OPTION)

19. Presented by L.M. Mak 19 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation RAFT FOOTING CONSTRUCTION

20. Presented by L.M. Mak 20 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation PODIUM CONSTRUCTION

21. Presented by L.M. Mak 21 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation CARRY OUT SITE FORMATION (FOR PILE FOUNDATION OPTION)

22. Presented by L.M. Mak 22 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation PILE FOUNDATION CONSTRUCTION

23. Presented by L.M. Mak 23 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation PODIUM CONSTRUCTION

24. Presented by L.M. Mak 24 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation B B Proposed School Layout Plan (Section B-B)

25. Presented by L.M. Mak 25 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation STRIP FOOTING CONSTRUCTION

26. Presented by L.M. Mak 26 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation STRIP FOOTING CONSTRUCTION

27. Presented by L.M. Mak 27 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation 2. Tuen Mun Existing Site Investigation Location Plan

28. Presented by L.M. Mak 28 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation Record of Existing Site Investigation Extracted from CED Contract No. GE/95/12 dated December 1997 D73

29. Presented by L.M. Mak 29 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation Record of Existing Site Investigation DH4

30. Presented by L.M. Mak 30 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation Record of Existing Site Investigation DH4

31. Presented by L.M. Mak 31 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation Record of Existing Site Investigation DH6

32. Presented by L.M. Mak 32 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation Record of Existing Site Investigation DH6

33. Presented by L.M. Mak 33 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation Record of Existing Site Investigation DH6

34. Presented by L.M. Mak 34 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation Record of Existing Site Investigation DH11

35. Presented by L.M. Mak 35 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation Record of Existing Site Investigation DH11

36. Presented by L.M. Mak 36 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation b. Proposed Flyover Site Layout Plan

37. Presented by L.M. Mak 37 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation b. Proposed Flyover Details : Column Size=3m x 3m DL = 5987.5kN LL = 1074.0kN Total = 7,062kN

38. Presented by L.M. Mak 38 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation c. Foundation Options i). Footing (Assume 6m x 6m) 6m x6m 7,602kN/(6x6m 2 ) = 196kPa

39. Presented by L.M. Mak 39 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation 1. Bearing Capacity => From Geoguide 1 Figure A1 & A2 q ult =c’N c s c i c t c g c +0.5g’B’N g s g i g t g g g +q’N q s q i q t q g q

40. Presented by L.M. Mak 40 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation => From PNAP 141 Allowable Bearing Pressure for Fill = 50-100 kPa < 196 kPa

41. Presented by L.M. Mak 41 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation 2. Induced Settlement => Total settlement  25mm => Differential settlement  1:300

42. Presented by L.M. Mak 42 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation ii) Piles =>Driven Piles - Capacity: Steel H Piles 305 x 305 x 198kg/m Grade 55C Carrying Capacity = 3140 kN For imposed load of 7,062 kN Pile No. = 7062 / 3140 = 2.2 nos (say 3 nos.) How about negative skin friction (NSF)?

43. Presented by L.M. Mak 43 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation NSF Equation: Effective Stress Method f n =  v ’ wheref n : Ultimate negative skin friction  Empirical factor 0.2 to 0.25 for clay materials 0.35 to 0.5 for sand materials  v ’:Effective vertical stress

44. Presented by L.M. Mak 44 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation For NSF from ground level to the bottom level of compressible layer: where: P er is the perimeter of the pile D is the depth of the bottom of compressible layer

45. Presented by L.M. Mak 45 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation NSF at Fill layer:  v ’ =  ’h =10h & take  =0.5 for fill materials NSF at Marine Clay layer:  v ’ =  v ’ fill +  v ’ marine clay =  h & take  =0.25 for clay materials

46. Presented by L.M. Mak 46 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation Total NSF = 181P er + 273P er = 454P er (kN) For 305 x 305 x 198 kg/m grade 55C, P er =1.964, NSF = 1.964 x 454 = 892 kN Net positive pile capacity = 3140 – NSF = 3140 – 892 kN = 2248kN No. of steel H piles required = 7062 / 2248 =3.2 nos. (Say 4 nos.) - Cost

47. Presented by L.M. Mak 47 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation Bored Piles: Assume 1.5m  bored piles terminated at M/SDAndestile (q a = 5,000kPa) 1.5m  M/SD Andesite q a = 5,000kPa Bearing capacity of pile =  D 2 /4 x 5000 = 8836kN>7062kN How about NSF?

48. Presented by L.M. Mak 48 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation Total NSF = 454P er (kN) For 1.5m  bored piles, P er =  D = 4.71m NSF = 4.71 x 454 = 2139 kN Net positive pile capacity = 8836 –NSF =6697kN No. of 1.5m  bored piles required = 7062 / 6697 = 1.1 nos. (Say 2 nos.) - Cost

49. Presented by L.M. Mak 49 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation Foundation Options Options Technical Aspects Cost Aspects Programme Aspects 1. Footing i)Bearing Capacity Failure ii)Excessive settlement (technical not acceptable) Not considered further 2. Pile: a) Steel H Piles 4 nos. @305x305x 198kg/m(50c) ? ? b) Bored Piles 2 nos of 1.5m  ? ? Recommendation : ?

50. Presented by L.M. Mak 50 The Hong Kong University of Science & Technology Civil Engineering Department – Civl 395 – Project Implementation Thank You