Case Study : The Tessarina

1. Piling Works Case Study : The Tessarina

2. Types of Piling Works involved on site • Grout Piling • Sheet Piling :

3. Grout Piling( Deep Cement Mixing Method) • The Grout-mix column is a soil improvement technique which is used to improve the strength of the sub-soil. By mixing the cement into the soil, the soil strength is increased significantly. This is a fast and economical method for soil stabilization.

4. Applications • An alternative method to sheet piling for retaining structure. • Improves accessibility/trafficability of the weak ground

5. Applications • Prevention of ground heaving.

6. Applications • Prevention of sliding failure for high banking/excavation.

7. Applications • Reduction of settlement by improving ground bearing capacity.

8. Applications • Increase the bearing capacity of the soil to support light structure. • An alternative method to jet grouting for ground improvement.

9. Advantages • Minimal effect on ground heaving • Minimal vibration and noise pollution • Impermeable retaining wall • Left in and used as external form for basement walls • Fast • Cost effective

10. Mix design • The amount of cement to be mixed into the soil is dependent on the required design strength. Other parameters are water/cement ratio, rate of inflow for grout, rate of withdrawal for stirrer, type of execution- W/V type, rotation speed for stirrer and original soil properties. This is further verified by laboratory and in-situ testing.

11. A typical guideline is provided in the following table :

12. Equipment • Sanwa Continuous Flight Auger equipped with grouting facilities. Model No. D150HP-SB mounted on P&H 85P/100P • Diameter of Grout-Mix Pile availability D = 400-1200 mm (Grout- Mix Pile and Reinforced Grout-Mix Pile with H-Beam)

13. Construction Procedures of grout piling • First the surveyor will determine the position of the grout pile.

14. After determining the position of the piles, the auger rig is place in position of the first pile.

15. Tungsten carbine drill bit is used to start augering.

16. Pumping of cement grout while augering

17. Mixing is by auger rotation as a form of mechanical agitation.

18. Withdraw auger in anti-clockwise rotation • Installation of the first grout-mix pile is completed.

19. String method is used to mark out the position of the rest of the piles and to ensure alignment of the piles.

20. Auger rig have to be place at the second pile position shown below: • This is done to ensure that the first pile is harden before another pile can be driven beside it 1st 4th 2nd 5th 3rd

21. Then repeat the whole procedure again. • After a series of piles is done it forms a retaining wall for the construction of the basement.

22. Sheet Piling • Sheet piling involves the installation of sheet materials, usually in a row with edges of these sheet materials engaging or interlocking one another, so as to form a continuous wall to resist horizontal pressure resulting from earth or water loads.

23. Uses of Sheet Piling • Resist lateral forces of the earth • Reduce water seepage into basement • Construction of cofferdam • Support sides of basement

24. Advantages • Sheet Piles can be installed before excavation • Sheet Piles have watertight interlocking joint • Less amount of bracing is required • Sheet piles may be driven deep down into an impermeable stratum to cut off the flow of ground water

25. Types of Construction for Sheet Piling -Using Vibro Piling ( Cofferdam) - Using Hydraulic Driving Machine (Silent Piling)

26. Sheet Piling Using Vibro to construct Cofferdam • Vibro is percussion hammer used to drive sheet piles into the ground. The vibrating effect produce by the Vibro drive the sheet piles into the ground.

27. Advantages of using Vibro • Cheaper than silent piling • Traditional method for constructing cofferdam • Speed in construction

28. Procedure of Sheet Piling Using Vibro for Cofferdam • Firstly, the land surveyor will determined and mark out the area the cofferdam is to be located.

29. The sheet pile will be hoisted up by the crane.

30. With the coordination of the worker and the crane operator communicating through hand signals, the sheet pile is place in position, connecting the water seal joint with the previous pile.

31. The Vibro is then hooked by the crane • Hoist up to the top of the sheet pile.

32. After much adjustment the Vibro is fixed to the sheet pile.

33. Slowly the Vibro will drive the sheet pile 2/3 into the ground with its vibrating motion, this sheet pile will become the anchor pile.

34. After the sheet pile is driven into the ground verticality of the sheet pile will be checked. • The Vibro will then be removed from the sheet pile.

35. Then a series of piles will be pitch adjacent to the anchor piles. • Partially drive the last pairs to the same depth as the anchor piles. • Drive the remaining piles to their final set. • Then continue until the four sides of the cofferdam is completed. • Strutting and bracings will be subsequently installed while excavating down.

36. Sheet Piling using Hydraulic Driving Machine ( Silent Piling) • Hydraulic drivers are machine using hydraulic forces to push piles into suitable sub soils such as clays, silts and fine granular

37. Advantages of Silent Piling • Vibrationless • Very quiet almost silent • Ideal for installing sheet piles in close proximity to other buildings • More accuracy and verticality when installing • Construct faster than Vibro piling • Less manpower needed to construct

38. Procedure of Silent Piling • Firstly, the land surveyor will determined and mark out the position of the sheet piles.

39. The pile will be hoisted up by a crane.

40. Hydraulic driver will be position on a temporary decking at the position of the first pile.

41. The sheet pile will then be place into the cramp of the hydraulic driver with manual help.

42. Operator using remote control adjust the sheet pile properly.

43. Using remote control operator adjust sheet pile in position and at the same time loosen the ground soil for easier driving.

44. The driving operations entails lowering and connecting the hydraulic driver to the heads of a panel of piles, activating two rams to drive a pile for the full length of the stroke. The process repeats until the required penetration of the pile is reached.

45. After the first pile is driven in, the operator check for verticality.

46. Operator using remote control to shift the posistion of the machine onto the completed piles . • The second pile is place in position • The whole process continues.

47. After a series of piles is drive in and interlocking each other it becomes a retaining support for the basement construction.