• Home
  • Download PDF
  • Order CD-ROM
  • Order in Print
Pile-Driving  Caps
Obstruction and Refusal

Equipment Operator Basic - Beginning construction equipment operators manual
Page Navigation
  322    323    324    325    326  327  328    329    330    331    332  
The steps required to install the hammer in the leads in the horizontal position are as follows: 1.  Block  the  leads  about  18  inches  off  the  ground in several places, keeping them as level as possible. 2. Using a forklift, place the hammer at the base of the leads with the top of the hammer towards the top of the  leads. NOTE: On  underhung  leads,  the  fuel  pump  faces upward. On extended four-way leads, the fuel pump faces  downward. 3. Have the forklift approach the hammer from the pile cap end. 4. Adjust the forks so they will just fit the lead guides on the hammer. 5. Pick the hammer up in this manner and guide the top end into the leads as far as it will go without hitting the forks. 6.  Block  up  the  hammer  that  protrudes  and reposition the forklift to push the remainder of the hammer into the leads. NOTE: The crane line may assist in pulling the hammer into the leads. 7. Secure the hammer to the bottom of the leads. This will keep the strain off of the leads, as they are raised to the vertical position by the crane boom. Installing the hammer in the leads in the vertical position is as follows: 1. Raise the boom and leads from horizontal to vertical and install the catwalk. Continue to raise the boom as high as practical and safety permits. 2. Hoist the hammer to a vertical position and position it under the leads. It takes a combination of lowering the boom and hoisting the hammer to slide the hammer onto the lead guides. If this does not allow enough clearance to install the hammer vertically, use the following: 1. Use a deep ditch or loading ramp for additional clearance for the hammer. 2, Set the hammer in an excavated hole to clear the bottom  of  the  leads. 3. The hammer can be partially submerged in water to  gain  additional  clearance. PILE-DRIVING TECHNIQUES AND TERMINOLOGY Care must be taken during pile driving to avoid damaging the pile, the hammer, or both. The pile driver must be securely anchored to avoid a shift of position. If the hammer shifts while driving, the blow of the hammer will be out of line with the axis of the pile and both the pile and hammer may be damaged. Carefully watch the piles for any indication of a split or brake below the ground. If driving suddenly becomes easier or if the pile suddenly changes direction, a break or split has probably occurred. When this happens, the pile must be pulled. Springing and Bouncing “Springing” means that the pile vibrates too much laterally from the blow of the hammer. Springing may occur when a pile is crooked, when the butt has not been squared off properly, or when the pile is not in line with the  fall  of  the  hammer.  In  all  pile-driving  operations, ensure the fall of the hammer is in line with the pile axis; otherwise, the head of the pile and the hammer may be damaged and much of the energy of the hammer blow is lost. Excessive  bouncing  may  come  from  a  hammer which is too light. However, it usually occurs when the butt of the pile has been crushed or broomed, when the pile  has  met  an  obstruction,  or  when  the  pile  has penetrated to a solid footing. When a double-acting hammer is being used, bouncing may result from too much steam or air pressure. With a diesel hammer, if the hammer lifts on the upstroke of the ram piston, the throttle setting is probably too high. Back off on the throttle control just enough to avoid this lifting. If the butt of the timber pile has been crushed or broomed more than an inch or so, it should be cut back to sound wood before driving operations continue. Driving Bearing Piles in Groups Bearing piles are frequently driven in groups, as in a pile group which will support a column footing for a building or in closely spaced rows, as beneath a wall. When piles must be driven in closely spaced groups, these  principles  are  observed: 1.  When  a  pile  is  driven  into  sand  or  gravel deposits, the soil must be compacted or displaced an amount equal to the volume of the pile. If the deposit is quite loose, the vibration of pile driving frequently results  in  considerable  compaction  of  the  soil.  The 12-48







Western Governors University

Privacy Statement
Press Release
Contact

© Copyright Integrated Publishing, Inc.. All Rights Reserved. Design by Strategico.