Ct2 Precast concrete piles

Precast concrete piles

1. PRECAST CONCRETE PILES Ng Bee Yee Chong Lih Yen Cheah Aun Ni Kuek Sze Ting Hoe Pooi Yee Khairi Fariz Chong Kian Loong

2. 1. Name 1 project in Malaysia that has used Precast Concrete Piles as the building component. P etronas T win T ower

3. D istribute the weight of the finished structure safely, reducing the risk of structural failure or collapse . M ade to resist compression, tension, bending and torsion forces during manufacturing, transportation, handling and installation M aintaining structural integrity and design C reated off-site and then piledrived into place to allow for greater control of the finished product. F unction of Component

4. A dvantages Quality can be controlled and monitored much more easily Piles can be precast to the required specifications. The work is neat and clean, supervision of work is minimal. And storage space required is very much less Driven piles are the most favoured for works over water. Bearing capacity of pile increased when driven into granular soil compacts the adjacent soil mass

5. D isadvantages These piles are usually very heavy. So special equipments are required for handling and transportation . Sufficient care must be taken at the time of transportation, otherwise piles may break. For embedding these piles in field heavy pile driving equipment is required .

6. These piles are costly as extra reinforcement is required to bear handling and driving stresses Once constructed, it is not possible to increase the length of the pile (as per the site demand) If the pile is found to be too long, during driving, it is difficult and uneconomical to cut. Driving these piles created a lot of noise pollution and vibration. May cause settlements on neighbouring buildings. Can be damaged during driving. Replacement piles may be required. Cannot be driven with very large diameters or in condition of limited headroom.

7. C onstruction P rocess Precast Concrete Pile The precast concrete pile is a prefabricated, high-strength prestressed concrete column, impact driven into the soil by means of an adjustable hydraulic or diesel hammer Fields of application Ideal solution for cost-effective piling in homogeneous geotechnical conditions and for carrying low to medium loads Extensive preliminary soil investigation is required in order to determine both the nature and the behaviour of the layers of soil Wide range of applications Given the prefabrication and the delivery time of the precast piles, the pile must be dimensioned depending on the definitive pile load and the soil conditions before execution Adequate solution for soil profiles with very weak resistances in the upper strata, where excess use of concrete can be expected when installing cast-in-situ piles

8. If installation is to be carried out, then the following factors should be taken in to consideration: Size and the weight of the pile Driving resistance which has to be overcome to achieve the design penetration Available space and headroom on the site Availability of cranes and Noise restrictions which may be in force in the locality Methods of pile driving can be categorised as follows: Dropping weight - Compressed-air hammers or double-acting pile hammer Vibration - Vibratory hammers Jacking - Hydraulic jack Jetting - water jetting

9. Meet OSHA safety requirements A blocking device, capable of safely supporting the weight of the hammer, shall be provided for placement in the leads under the hammer at all times while employees are working under the hammer . No employee shall be permitted under precast concrete members being lifted or tilted into position except those employees required for the erection of those membe r Type 1:Cast Iron Pointed Shoe Type 2: Rock Shoe/OSLO Point Type 3: Standard X-pile shoe Type 4 : Plain Shoe What is Pile Shoe ? a point that fitted to a lower end of a wooden or concrete pile to facilitate penetration of the ground The pile shoe attachments to concrete piles are attached during manufacturing process or in the factory.The chosen type of pile shoe is depends on the soil condition. Type 1 :Can be chiselled into any type of rock to ensure proper seating Type 2 :For hard driving & socketing into hard strata Type 3 :For moderate to hard driving Type 4:For easy to medium hard driving Type of Pile Shoe Decided During Manufacturing Process Quality Control Checks on finished piles for straightness, cross-section, alignment of joint and fittings. Slump test on concrete batches . B efore I nstallation Test on aggregate samples for grading and silt content.

10. Positioning of the prefabricated concrete pile The pile is driven into the soil with an impact pile driving hammer (diesel hammer or hydraulic drop hammer). Provides adequate protection to the pile head during driving. With control of driving achieved by measuring the set, the pile is driven into the resistive soil layer to a depth equal to one time the pile diameter. Fig.: Protecting pile head damage during driving Special timber packing or a synthetic cushion block construction sequence

11. P roblems O ccurred

12. D eformation of Piles

13. P ile T ilts M oves / Walks

14. H igh W ater T able

15. W eather