日 Figure 1-5 Hercules typeof pile joint 1.4.10 Driven and cast in place Concrete piles Two ofthe main types used in the UK are:West's shell pile:Pre cast. reinforced concrete tubes,about 1 m long,are threaded on to a steel mandre and driven into the ground after a concrete shoe has been placed at the front of the shells.Once the shells have been driven to specified depth the mandrel is withdrawn and reinforced concrete inserted in the core.Diameters vary from 325to600mm. Franki Pile:A steel tube is erected vertically over the place driven,and about a metre depth of gravel is placed atthed drop hammer,1500 to 4000kg mass,compacts the aggregate into a solid plug which then penetrates the soil and takes the steel tube down with it.When the required depth has been achieved the tube is raised slightly and the aggregate broken out.Dry concrete is now vadded and hammered until a bulb is formed. Reinforcementis place med until the pile top comes up to ground levels placed an ed in position and more Figure 1-5 Hercules type of pile joint 1.4.10 Driven and cast in place Concrete piles Two of the main types used in the UK are: West’s shell pile : Pre cast, reinforced concrete tubes, about 1 m long, are threaded on to a steel mandrel and driven into the ground after a concrete shoe has been placed at the front of the shells. Once the shells have been driven to specified depth the mandrel is withdrawn and reinforced concrete inserted in the core. Diameters vary from 325 to 600 mm. Franki Pile: A steel tube is erected vertically over the place where the pile is to be driven, and about a metre depth of gravel is placed at the end of the tube. A drop hammer, 1500 to 4000kg mass, compacts the aggregate into a solid plug which then penetrates the soil and takes the steel tube down with it. When the required depth has been achieved the tube is raised slightly and the aggregate broken out. Dry concrete is now added and hammered until a bulb is formed. Reinforcement is placed in position and more dry concrete is placed and rammed until the pile top comes up to ground level