Here in Louisville, Ky. (and in a few other cities) the practice of "flushing and jetting" is the de facto standard for trenches under pavements. The local sewer and drainage authority (MSD) has a rather elaborate specification for the sand which is to be subjected to this practice...
re: "Is this the highest amount of rainfall for a 24 hour period that was recorded for the last 100 years?"
No.
It is the amount of precipitation associated with a 1% probability of occurrence for any give year. There may be a thousand years without it ever occurring. It may...
Or, maybe you'd like a simple approach.
Assuming that the lower end of the pipe is full and the you know the slope and the elevation of the water surface: Calculate the length to the point where the top of the pipe is at the water/air interface. Then, calculate the length to the point where...
The biggest factor is in the storm distributions. The rational method uses a constant intensity storm for its model. The SCS method uses a storm that is initially gentle but that has a period of much greater intensity at some time during the event.
The second largest factor is the difference...
I'd suggest that, rather than drilling, this may be a situation where getting the ol' backhoe onto the site is appropriate. Since you've given no information about the geology, I can't suggest anything more than digging a few holes so you can get a good idea of the soils and, perhaps, using the...
Michelle,
Perhaps you'd get more of a response if you indicated what you were using the "turbidity barriers/silt curtains" for. There are a few conditions where they're useful and quite a few where they're not.
Bill Holt
I'm trying to think of the conditions under which I'd "certify" that a fill would support, with no affects that might in the future be considered unacceptable, any load.
Can't do it. Would wonder about anyone willing to do so unless they had total control over sampling, testing and...
Ah yes, the good old "get it right" the first time approach. I've heard of that. Seen it a few times too.
I imagine, however, that in this situation any repair acceptable to the owners that leaves out the lawyers will be less costly than any solution that includes them.
Bill Holt
Assuming you're satisfied that the deflection process is compete and you've established that there are no leaking joints as a result of the deflection, it seems to me that you haven't asked and answered a fundamental, commonly missed question: Does it matter?
A 6" sag in a 12" pipe...
Jackson,
I'd be real concerned about modeling peat as a clay. My experience is limited to testing a waste material that was very much like a peat, but the curves were not at all like what you'd expect to see with a clay. Rather than consolidation, compression predominated which largely...
Note: Working out the coefficients from the 100 year data is probably the weakest approach, but my hunch is that it will probably still be ok. Your precision in reading from the map is a factor, as is the accuracy of the map.
mr = 36.31055551
br = 44.4089066
B = 0.81070128
C =...
Alice,
The sands are easy to deal with, so far as the drainage in concerned, as are the clays for different reasons. The sands will drain into the gravel layer, the clays eventually won't - or at least not much.
The silts, if truely silts, are potentially a mechanism for failing your...
Kaizer,
Please drop the all caps. Hard to read.
What you seek is about one-half of a hydraulics/hydrology design course. Perhaps your firm should hire an engineer who's taken the course already.
Bill Holt
If I were in your place, I'd certainly consider it - but you'll need to dig out your copy of the Concrete Pipe Design Manual to assess the adequacy of the backfill for the anticipated loading.
As you describe the material, it sounds ideal, but you'll need some additional thickness above the...
Good news, bad news. I found my original work on this stuff (done a number of years ago for the same reason you're doing it) but don't seem to be able to locate my TP-40!
Here's the general equation. Other forms are possible, but I've found this to generate good result with an average error...
