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Excavating and Lifting. Hmwk Ch 2 # 1,2,5,8 Ch 3 #2,4,6,10. Excavators & Crane Shovels. Crane Shovel – cable operated machines Shovel Backhoe Dragline Clamshell Mobile crane Pile driver. Excavators & Crane Shovels. Hydraulic Excavators Faster cycle time than shovels
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Excavating and Lifting Hmwk Ch 2 # 1,2,5,8 Ch 3 #2,4,6,10
Excavators & Crane Shovels • Crane Shovel – cable operated machines • Shovel • Backhoe • Dragline • Clamshell • Mobile crane • Pile driver
Excavators & Crane Shovels • Hydraulic Excavators • Faster cycle time than shovels • Higher bucket penetrating force • More precise digging • Easier operator control • Attachments – pg 41 - 43
Excavators & Crane Shovels • Parts – Figure 3-2 • Carrier or mounting • Track • Excellent on-site mobility – will go anywhere • Low ground pressure – good for low trafficablity soils • truck & wheel mountings • Greater mobility between job sites – faster • Require better surfaces to work on • Revolving superstructure containing power and control units • Front end assembly
Production • Need to know volume of material in one bucket load Figure 3-1 • Plate line capacity – volume contained in outline of bucket • Struck capacity – volume when mat’l is struck off even w/ sides of bucket • Water line capacity – assumes material only to lowest edge of bucket • Heaped capacity – max volume that can be placed in bucket without spillage
Production • Ratings usually based on struck volume • Assumption is made that since bucket is usually heaped that a 5 cy bucket will pick up 5 cy of bank not loose • Better to use bucket fill factors – Table 3-2
Operation & Employment • Excavators • Fig 3-3 & 3-4 • Trenching work • Production estimating • Production (LCY/hr) = CxSxVxBxE • C – cycles/hr • S – swing depth factor T 3-4 • V – heaped bucket volume • B – bucket fill factor • E – job efficiency • Trenching work may also require a fall in factor for dirt going back in the trench T 3-5
Shovels • Larger than excavators • Good for excavating above track line • Digs using • Breakout force and crowding force • Can form its own roadway • Can shape sides of cut and dress slopes • Should have a vertical face to dig against • Production is found same way
Trenching Technology • Good for digging a narrow trench with the spoil going to the side of the trench • Chain trenchers, ladder trenchers, bucket wheel trenchers
Trenchless Tech • Pipe jacking • Thrust boring • Pipe bursting
Cranes • Lifting, lowering transporting loads over 3D • Components Fig 3-22 • Load chart F 3-24 • Heavy Lift cranes • F 3-25 – 26 • Tower Cranes • F 3-27 - 29