The filter is the same in both options, and revenues generated are the same in both cases as they make their permitted GPD either way. The existing clarifier is very different from the potential replacement, and we have no good records of maintenance of the existing one. I’m just looking for a...
Hello,
I am doing an alternatives analysis of replacing a municipal water plant filter and clarifier vs. replacing a filter and repairing an existing clarifier. What would be a reasonable estimate of annual maintenance cost as a percentage of initial cost, and a source for that number? I suppose...
Thanks, I found it just after I posted. It is one of those things that I knew I had seen but I could not remember where. It is so obvious, and I never paid it much thought. I may add that note on plans so none of my own jobs end up this way.
I am researching standards for someone (and thankfully it is not my project). The contractor did not have all the rebar in place before he began to place the concrete, and began to stick it in after the concrete was in the forms. I believe the last of it was DRIVEN in after the concrete had...
Fx = 0.01Wx (1.4.1) would be simple enough, but they specifically want me to use peak horizontal velocities associated with an MCE. I have determined Sds and Sd1, and my Sds gives me a risk category A from Table 11.6.1 in ASCE 7-10. So now that I have them, how do I apply these to design...
Hello,
I am working on a project, and a comment received on a submission suggested “adding consideration for peak horizontal velocities associate with a maximum credible earthquake and/or operating basis earthquake”. The project is located in an extremely seismically stable area (in the US),and...
I am designing a reinforced concrete column, 24" diameter, with 1.5" cover. f'c = 3000 psi, fyt=60,000 psi.I find the minimum volumetric reinforcement ratio to be 0.069. By ACI-318, looks like I can choose from #3,4,or 5 bar for the spiral. With the diameter of the core as it is (21"), I get a...
In the case of a moving stream that exerts force on a dam, should the moment arm of the Fstag for overturning the wall be H/3 (as with hydraulic force) or H/2? Or something else entirely?
Thanks in advance, Engingguy
Hello folks,
I generally use a shear strength of 0.6 Fy for rebar, but I can't find the reference in ACI 318-14 for a shear factor. I have seen values from 0.5 to 0.75 Fy used,so my 0.6 seems a safe middle value, but for the life of me can find no reference to where that comes from. Can anyone...
Best choice is to check the law in your state. As a PE, in my state I can legally perform surveying ancillary to the practice of engineering but must call in a licensed surveyor to do property surveying. I have a working relationship with licensed surveyors I know and trust and use them when the...
Thanks, that was useful.
I have a triangular slab with upper and lower mats, and placing the splices while trying to maximize the use of 20 ft lengths is quite interesting. Moving a splice to provide clearance from another places it closer to yet another splice. Got er done, though.
I am looking in ACI 318-14 for a spec for the stagger distance between lap splices but can't find one. I am using #4 epoxy coated rebar, 60,000 psi. Concrete is 3000 psi and the splices are Class B. I need to come up with a better splice detail note than "Just stagger the splices so the concrete...
I have seem contractors overlap PCV water stop, make their own corners in the field (most manufacturers say that is a no no), and not hog ring it correctly. And with end forms in place it would be hard to inspect. I will look into Hydrotite.
This is a good forum. Thanks.
I like the PCV water stop idea. Just specified a bulb type PCV water stop for a dam. May dig that out of the file. I like the ribbed type, because I like to practice safe seal.[bigsmile]
This shed will be near to a stream and I am taking an extra step or two to control seepage of contaminated...
Thanks for your prompt reply Motorcity. I am specifying epoxy coated rebar for this job, might as well use epoxy coated dowels as well. I wonder if they work as well as they could after contractors bang them around. They generally don't like to pay the extra for epoxy coated bars but a salt...
Hello. I am designing the foundation and walls for a small salt storage shed. Any suggestions for a brine resistant filler for the slab joints? Construction joints in this case, not control joints. I am also specifying stainless steel dowels for load transfer. I was thinking of epoxy coated...
