Of course ... one should not use the perc rate for gravel (the gravel band serves as a medium between the drywell and virgin soils) ... a drywell typically is a perforated manhole with a gravel band surrounding it (2 to 3’ in diameter - most agencies require a solid bottom on the manhole so the...
Is there a standard way to calculate the drainage potential of a drywell given a vertical percolation rate (derived from the standard falling head test). In the past I have used just the bottom of the gravel band (gravel band usually 3' in diameter)
and also have used both the bottom of the...
Would one of you experts out there give me the low down on the various compaction requirements such as aashto t99/t180 (the maximum density and optimum moisture test) and the inplace density and moisture test AASHTO T-310. I guess my question is if I instruct the contractor to compact the...
transitioning via vertical curves for a 1 to 2% grade break for roads is typical, but I think that your question is related to parking lot grading ... It is not typical to put in vertical curves in parking lots (I think that the contractor is responsible for the smooth transitions, 1% minimum...
can anyone give me a good specification for the installation of a 10,000 gallon septic tank ... i.e. what type of backfill should I spec out and or any instructions to give to the contractor to make sure it is installed correctly (the septic tank will be part of a STEP system) ... thank you in...
I am new to water distribution system analysis ...
When using the following equation
Qf=Qt[(Ps-Pf)/(Ps-Pt)]^0.54 to get an approximated fire flow (Qf) given a theoretical fire flow pressure (Pf)(usually 20 psi) it is my understanding that the static pressure (Ps) and residual pressure (Pt)...
What guidelines might I follow for the following:
Beginning at a 4 way intersection my roadway width is 30' transitioning down to a 24' roadway width. I do not think that "L=[W(S)^2]/60" (20-25 mph) applies as I am not reducing the number of lanes or using the transition as a speed...
can anyone tell me a source for accurate modulus of elasticity values for various depths of compacted granular backfill ... 3/4"-0, 1-1/2"-0, 4"-0, a lot of text books show how to calculate stresses and strains but do not give any hints as to the typical material property ...
How does one calculate the head loss through a manhole that does not have channeled and or deflected flow ... i.e. a sedimentation manhole and drywell system overflowing into a pond ... typical calculations can deal with the entrance, exit, bend, and junction losses in channeled / deflected...
I am building a Fire Truck Access road (gravel) and the cross section is going to be something like 6" of 3/4" minus over 9" of 1-1/2" minus. I am building this road over adverse soils (saturated garbage fill, maybe clayey silty loom?? with zero percolation properties). My...
Can anyone Tell me where to find a listing of the
SCS type 2 Rainfall Distribution (10 minute increments) for use with SBUH (Santa Barbara Urban Hydrograph) ... my textbooks talk about it but do not actually list it ... and maybe some examples for me to check my hydrograph spreadsheet for...
what is the best way to calculate the stress' on a subbase under a 3 layer gravel road bed, i.e., 6" of 3/4"-0, over 9" of 1-1/2" -0, over compacted subbgrade (60,000 lb load). Is the 3 layer theory as stated in Yoder/ Witczak (principles of pavement design, 2nd edition)...
Can anyone tell me how (or where I can get an example) to calculate the rate of water leaving a dry well given the perk rate of the soil?
Thanks in advance,
