pile driving vibrations and settlement 3

[Chopdog]

I have a potential client claiming that pile driving operations for a bridge construction project adjacent to his house (piles driven < 50' from house) have caused structural damage to an addition of the house. I reviewed the house last night and the damage is definitely caused from differential settlements. First, I am searching for more current information on the subject than I currently have. Any advice? Second, I am hesitant, at this point, to accept the work because if the results of my investigation and analysis indicate that the addition to the house was not properly founded in the first place, and not the result of the pile driving operations, who pays me? Any more advice?

 

[PEinc]

Yes, get a sizeable retainer up front. You are correct in considering if the house addition had problems before the pile driving.

http://www.PeirceEngineering.com

 

[oldestguy]

I'd go slow here. The best info I'd want is actual vibration measurements on site while the piles are being driven.

Otherwise it is more a matter of opinions and that then results in other experts and attorneys getting into the situation.

Credible witnesses might help, and if the cracks appear fresh that also might help. How fresh?

The owner may go directly to the contractor or bridge owner with a claim and perhaps will get something to keep from going to court.

Unless the owner is willing to invest in vibration studies, soils investigations and the like, it probably is not worth it for them or you.

 

[PEinc]

The house supposedly already has damage from pile driving. It's probably too late for vibration monitoring.

http://www.PeirceEngineering.com

 

[hokie66]

I would suggest to the house owner that his first step is to complain to the owner of the bridge and request rectification. There should have been a preconstruction inspection of his property, done by an independent inspector appointed by the bridge owner or builder. The critical issue is not how well the house is founded, but whether the damage was preexisting. If an inspection was not done prior to construction and the house owner receives no satisfaction, his next step should be to retain a lawyer, and the request should be turned into a demand. Then if the lawyer needs technical assistance, he can come to you.

 

[Ron]

Chopdog...I believe PennDOT has requirements for vibration monitoring and pre-construction condition assessment. The Florida DOT has such requirements (see attachment).

hokie66 is right on target. Get the attorney involved in the beginning for protection of your work product and to get the right perspective on the demands.

Definitely get a retainer up front.

 

[Mickney]

Just a suggestion that is non-technical: I would ask the owner for all photos ever taken in the house and particularly the addition. See if you can see the history of the cracks in the photos. If the owner is reluctant to show you any pictures, do not accept the project. I do not know the severity of the cracking, so this approach may or may not be valid.

Also, review any construction drawings and documents relating to the addition. If none are available, be skeptical of the foundation.

With projects such as these, I have always found it very difficult to nail down one cause for cracking, which is what the owner is asking you to do. As an engineer, I would also make it my task to rule out other typical contributing factors (i.e. consolidation settlement, poor construction, shrink/swell of the foundations due to moisture variations, etc.).

 

[Chopdog]

The homeowner has contacted an attorney who directed the homeowner to get an estimate from a contractor. I suggested to the contractor that, at this point, beyond his estimate for repairs, he and I should not be in the loop. I told the contractor to inform the homeowner, or his attorney, to approach the bridge contractor and request compensation and then, if need be, demand it. I explained to the residential contractor that 1.) PennDOT does not require a pre-pile survey, but, that under PennDOT's Spec.'s the bridge contractor is directed to not damage private structures adjacent to the project and is to carry insurance to cover such circumstances, 2.) If repairs do proceed, that I should be hired by the residential contractor to provide any documentation/design/repair procedure that would be required by the building code officials, and 3.) If the attorney decides to eventually take the matter to the courts, that I should be retained by the attorney to provide technical assistance.

On the technical end, I have continued my research and have been finding more/better info. on the effects of pile driving vibrations on soil settlements.

Thanks for the replies.

 

[hokie66]

Chopdog,
I think you have given good advice. It is surprising that PennDOT does not require preconstruction inspections.

 

[Patgeotech]

Interesting thread and I had to provide some further comment - especially with regards to the requirement of no preconstruction inspection. Would be very difficult to prove whether there was damage to the house prior to the piling - wish one of your piling contractors would come work next to my house over here, if that is the sort of gamble they take. The piling and lateral support contractors in South Africa all undertake delapidation surveys of surrounding properties (in our codes) or ignore it at their cost - if the piling contractor does not do the delapidation survey, we as the Geotechnical Engineer 'force' it to be done so as to avoid liability issues that may later arise. As soon as a contractor starts piling, it is amazing how the local homeowners all appear on the scene to inform you that their house is damaged - normal common homeowners perceive vibration in a different manner as to what we, as Geotechnical engineers, perceive as acceptable vibration or 'normal' vibration. Something we sometimes forget due to our engineering training.

One problem that creeps up now and again on sites here, is when large excavations are undertaken for a new residential dwelling (say into a mountain slope) and the 'natural equilibrium' of the slope is disturbed - our municipalities/authorities do not enforce the need for a geotech assessment or delapidation survey on the owners doing the excavation, even when many neighbouring houses will be effected. I find it amazing how 'non-geotechnical specialists' seem to think no movement occurs when they excavate into the slope and think battering of the slope at 1v:1h will do the job - it sickens me sometimes to see the potential dangers and risks they take - but it does make my job easier when called in (on behalf of a moving house owner) and I challenge their geotech experience and ask why did you not undertake the delapidation survey.

 

[InDepth]

Out of curiosity, is there only 1 home there that was affected? If there were multiple homes with similar complaints then I think there are bigger issues...if it's an isolated situation, then it may be questionable, especially if the addition was founded on uncertified or uncompacted fill. ...I guess you never know unless vibration tests with soil borings to develop attenuation relationships were developed.

I do find it very odd that a preconstruction survey and visual documentation wasn't performed.

 

[dicksewerrat]

Check with the pile driving company. I know whenever we had to drive piles, we went around the neighborhood with camers. Took pictures of evry side of every bldg. within 3oo feet. Then had the vibration momitors set out. they probably have the records. Look for paint inside the cracks and dead plants.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[Chopdog]

A little update, although I have not heard anything since my last post.

For InDepth, to my knowledge, there was only one home affected. The home is the the first in a line of approx. 5 homes that set atop a relative flat streambank downstream of the bridge project. All other structures (except these 5) are a considerable distance from the bridge. The original house was not affected, only the addition. The addition was constructed on concrete pier footers, 4' depth, dia. ?, w/ 3 courses of CMU to the floor framing. The home owner stated how well founded it was becuse he placed the piers 4' deep. OK... I am not sure how familiar you are with west-central PA but the bridge is obviously on piling for a reason, the home, on private property, is at the upstream end of a large floodplain that the Corp of Engineers relies on for storage, and not to be condescending to the homeowner, but he just does not understand all the factors. I am treading lightly (careful of any comments I make) because I am very suspect of the bearing capacity of the addition's foundation as constructed.

For all. Concerning a preconstruction survey, one of the first things the project superintendant said to me the day I spoke with him was "we should have done a pre-pile survey"

For hokie66. No.., they do not. PennDOT covers this by placing the responsibility/liability on the contractor thru their general specifications.

For dicksewerrat. I can obtain any exploratory boring info., pile driving logs, field inspector's diaries, etc. that I want from PennDOT thru the sunshine laws here in PA. The pile driving subcontractor may be a different issue. I am not proceeding until somebody retains me. Concerning evidence of the age of the cracks... I was looking for something. The only thing I noted was some cobwebs, in one spot, in an opening/crack at the top of a wall in the one bedroom. Interesting thing was that this little bunch of cobwebs appeared rather dusty, not recently spun.

I have told anyone who questioned me in any way concerning this issue that the potential for the settlements to be caused by the pile driving exists, but, I can not say yea or nay, either way, without performing my investigation and analysis. I told the residential contractor that if the homeowner hires me, he may not get the answer he wants.

Again, thanks all.

 

[dgillette]

"A pile driver, when properly harnessed and kept within the channel of its legitimate functions, is, like a steam shovel or a bulldozer, a mastodonic mechanical creature assisting man in laudable conquest over obstacles holding back worthy enterprises in civilization's progress, but a bulldozer with an unsteady hand at the wheel can leave its prescribed route of travel and reduce adjoining structures to tin and kindling wood. The vibrations of a pile driver can be as damaging as the gigantic blade of the bulldozer if the operator ignores the existence of structures within the sweep of its invisible fulminations.

"A giant striding past a kindergarten should tread softly. A pile driver operating in the vicinity of frail or unsubstantial structures should restrain or mask its thunderous blows to the extent necessary to avoid inflicting avoidable damage.

"The fact that the pile driver itself did not come into contact with the plaintiffs' houses does not exonerate it from responsibility. Its invisible tentacles of terrestrial violence struck at the houses as surely as a cannon shot hits its target. A pile driver whose operator ignores the presence of dwellings within the perifery of its vibrations is as responsible for the resulting damage as the bulldozer which leaves the road and knocks down adjoining buildings."

--- Justice Michael Angelo Musmanno, Pennsylvania Supreme Court, in Dussell v. Kaufmann Construction Company, regarding damage caused by construction of the Walt Whitman Bridge.

They sure don't write them like that anymore. That's almost Shakespeare.

 

[Ron]

dgillette....excellent find! That's probably the most eloquent slamming of a contractor I've ever read!

 

[Chopdog]

Ron... I love it also. Have you ever read Lacer's inscription on his bridge in Alcantara, Spain? You make like it too, if you have a taste for such writing.

 

[PEinc]

Ron & dgillette,
I would like to point out that, although no longer in business, Kaufmann Construction was one of the most respected, competent, and thorough heavy and highway contractors in S.E. Pennsylvania for many years.

http://www.PeirceEngineering.com

 

[Ron]

PEinc....without regard to the competence and capability of the contractor, the SP justice's comments are spot on.

 

[Ron]

Sorry...that should be SC justice!!

 

[PEinc]

Yes, but he is a bit over-dramatic. Typical lawyer talk, this time from a judge (who is probably also a lawyer).

http://www.PeirceEngineering.com