Driving sheeting next to Utilities

[novs]

I was wondering does anyone have some general rules of thumb for the distance required when driving sheeting or piles next to utilities in different soil conditions?

Example: 15 feet in loose sands, 10 feet in compact sands, etc.

I have a job where driven sheeting was design (by others)13 feet from a 345kV underground electrial line and 7 feet from a 450 mm sanitary sewer line. The soil consists of medium compact to very compact Sand, with a deep water table. The utilities will be moved to these locations before the sheeting is driven, so we will accurately know the location of the utilities before driving. Thanks for your help.

 

[SlideRuleEra]

On industrial sites we have driven steel H-pile within 2 feet of buried 10 inch ductile iron pipe and (deenergized)electrical ductbanks with no problems. Steel sheet pile should not create a problem either.
Problems would most probably arise from soil movement when driving a displacement pile, such as wood or concrete.

 

[Focht3]

I look at each problem individually, since one must evaluate the amount of likely "free field" ground displacement as well as the stiffness of the soil and utility line.



Please see FAQ731-376 by [blue]VPL[/blue] for tips on how to make the best use of Eng-Tips Fora.

 

[DRC1]

1.Can not predict effect of vibratory pile driving on strctures.
2. Soldier pile and lagging will cause less vibration than sheetpiling.
3. Establish a plan to moniter the structures and settlement criteria prior to starting the work.
4. Always locate the utilities prior to driving to confirm location. Always call Call Before You Dig or Dig Safe or One Call to locate utilities. Even if you think you know where the are, Locator notification is often the law.
5. On some sites extraction can cause more settlement than installation.

 

[Mudcake]

novs,

Just a few comments for your considerations:

1. Since the utility in question will be in new, it may be quite tolerant to vibration. A moitoring program to document the before, during, and after construction conditions should be helpful.

2. The highest level of vibration in sheetpile driving typically happens during start and shutdown of conventioanl vibratory hammers. There are some resonant free and high frequency hammers that currently available in the market, that eliminate this problem.

3. There are two copanies in the US (Giken and ABI) now offer press in machines that install sheets by pressing it into the ground, and it is vibration free.

4. Another thing that we have done for utilities line that are not very deep, is to excavate a cut-off trench between the utility and the sheetpiles before driving. The cut off trench will need to be as deep as the utility line it self.

Hope these help.

 

[novs]

Thanks you for the assistance.

SlideRule, What soil type was at the site where you drove steel h-piles 2 feet from utilities?

Thanks again

 

[SlideRuleEra]

novs - On that project the soil was clays and silt with layers of sand at deeper levels.