Tutorial 2 (1)
- 1. TUTORIAL PRESENTATION Q8 BACHELOR OF QUANTITY SURVEYING (HONS) BLD 60204 CONSTRUCTION TECHNOLOGY II SECTION 3 | GROUP 1
- 2. 1 Differences between end bearing & friction pile
- 3. compare End Bearing Pile Friction Pile DIFFERENCES BETWEEN END BEARING & FRICTION PILE
- 4. End Bearing Pile Friction Pile These piles are used to transfer load through water or soft soil to a suitable bearing stratum. These piles are used to transfer loads to a depth of a friction load carrying material by skin friction along the length of pile. The bottom end of the pile rests or penetrate on a layer of strong soil or rock. (Supported by hard strata) Known as floating pile where the toes of the pile do not rest or penetrate into the firm layer of high bearing capacity soil which is too deep inside the ground. (Not supported by hard strata) The load of the building is transferred through the pile onto the hard strata, and also receive lateral restraint from subsoil. In a sense, this pile acts like a column. The load of the building is transferred to the adjoining soil by skin friction between the surface of the pile and soil, which in effect lowers the bulb of pressure. In other words, the entire surface of the pile is works for transferring the forces to the soil. DIFFERENCES BETWEEN END BEARING & FRICTION PILE
- 5. End Bearing Pile Friction Pile Load Bearing Resistance derived mainly from base. Load Bearing Resistance derived mainly from skin friction. Develop most of their friction at the toe of the pile, bearing on a firm layer. Develop most of the pile bearing capacity from the shear stresses along the sides of pile, and are suitable where harder layer are too deep. DIFFERENCES BETWEEN END BEARING & FRICTION PILE
- 7. PROCESS OF PRECAST PILES Precast construction is considered quick compared to cast in situ construction as it can be installed immediately and there is no waiting for it to gain strength. Driven precast piles are constructed by hammering the pile into the ground by pile driving plant. Piles of timber, pre-stressed concrete and steel are also used in this method. Shoe to ease driving
- 8. PROCESS OF PRECAST PILES Positioning of the prefabricated pile The pile is driven into the soil with an impact pile driving hammer (diesel hammer or hydraulic drop hammer). Special timber packing or a synthetic cushion block lends adequate protection to the pile 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. 1 2 3 4
- 9. PROCESS OF PRECAST PILES Different founding levels Reduce the section length Ensuring minimum waste and a safer working environment Sectional Precast Concrete Piles
- 10. 3 Advantages of Continuous Flight Auger
- 11. ADVANTAGES OF CFA Low Vibrations and noise Quick installation Economical Can see soil conditions Casing not required Can be installed in a batter Can be installed in low headroom
- 12. 4 Manufacturing process of reinforced concrete piles
- 13. MANUFACTURING PROCESS OF REINFORCED CONCRETE PILES 1. Raw material preparing - steel bar & wire 2. Steel bar cage making 3. Concrete feeding - the specially formulated high strength concrete is placed into the bottom half of the mold 4. Case covering & Bolt tightening - the mold is bolted closed 5. Steel bar tensioning 6. Rotary molding - level 1-7 for 11 minutes - the mold is spun at a high rate, the centrifugal force compresses the concrete against the inner wall of the mold 7. Steam chamber - curing for 12 hours 8. Demolding case Video : https://www.youtube.com/watch?v=yOhgMpk9Zu4
- 14. 5 Precaution measure when placing concrete through tremie pipe
- 15. PRECAUTIONS WHEN PLACING CONCRETE THROUGH TREMIE PIPE • The pile should be concreted wholly by tremie and the method of deposition should not be changed part way up the pile to prevent laitance from being entrapped within the pile • Concrete should be placed in sufficient quantity to ensure that during withdrawal of the tube, a sufficient head of concrete is maintained to prevent the in-flow of soil and water or bentonite slurry. • The top of the concrete in a pile shall be brought above the cut-off level to allow removal of all laitance and weak concrete before capping to ensure good concrete at the cut off level for proper embedment into the pile cap
- 16. PRECAUTIONS WHEN PLACING CONCRETE THROUGH TREMIE PIPE • When concreting is carried out under water, a temporary casing should be installed to the full depth of the bore hole so that fragments of ground cannot drop from sides of the hole into concrete as it is placed. When concreting under bentonite slurry, temporary casing is required only near the top • The tremie pipe and hopper should be a closed system to prevent penetration of water to prevent laitance • All tremie tubes should be scrupulously cleaned after use *Definition of laitance: an accumulation of fine particles on the surface of fresh concrete due to an upward movement of water (as when excessive mixing water is used)
- 17. 6 Sectional view sketch of pile cap, stump & reinforcement
- 18. SECTIONAL VIEW OF A PILECAP
- 19. ANY QUESTIONS?
- 20. THANK YOU ! STOP
- 21. SECTION 3 | GROUP 1 DR MYZATUL AISHAH KAMARAZALY DAPHNE TAN KAREN LIM LAU WAN YEE LIM XIAO SHI LOH WEI TING LOW WAN JING NGEOW YEE LING SAHIL GUNESH LECTURER 0329055 0329431 0328947 0324410 0328314 0329214 0329178 0328569 THE END!