Various construction issues in flyover construction
The following major issues are found in flyover construction.
Earthwork
- Excess excavated earth is not leveled and perfectly dressed at the evacuating place.
- Sand filling quantity underneath the floors is less.
- Underneath the floors, compaction process is imperfect.
- As per contract, compaction of earth work in filling is not accomplished.
- Lead chart for distribution of excess earth is not retained.
- As per drawing, the excavation of foundation is done in less quantity.
Concrete work
- Oversize, fragmented, soft aggregate is utilized.
- Sand with excessive silt content is utilized.
- Honey combed concrete.
- Available concrete is bulged and not in plumb.
- The density of PCC is less.
- Exact overlaps in reinforcement is missing.
- Reinforcement is uncovered.
- Usable bending wire contains lesser diameter.
- Expansion joint is not properly arranged.
- Curing and compaction is imperfect.
- Timber form work applied during contract arranged for steel form work.
- According to drawing, clear cover to reinforcement is provided.
Also Read : SOME VITAL THUMB RULES FOR PLACING COLUMN LAYOUT
Steel Work
- Sub-standard steel sections are utilized.
- Priming coat either is not provided or sub standard quality priming coat is provided on steel works.
- Tack welding is provided in place of continuous welding.
- Excess slag of welding is not eliminated.
- Density of sheets in rolling shutter is not adequate.
- Poor quality hinges and fitting are arranged.
- Steel hinges in M.S. frames are not secured with cutting slots.
- Flash butt welding is not provided in steel windows.
Bearing Failure
Failure of bearing occurs for the following reasons :-
- Surplus loads
- Overheating
- Normal fatigue failure
- Reversal Load
- Contamination
- Lubricant failure
- Misalignment
- Erosion
- Loose Fit
- Tight Fits
