Elon Musk has opined that the remains of the Key Bridge could be salvaged and used to construct a new bridge in 3 to 6 months. If Leprechauns (I'm not saying this is a realistic scenario) could unbolt all of the steel in the old bridge and gently bring the structural shapes to shore and...
My client is building a levee over a fairly thin (6 to 10 feet) strata of normally-consolidated very soft clay. The work is being done in stages. Settlements and excess pore pressures are being monitored in the soft clay. To move to the second stage of levee construction the contractor was...
There's a thread I couldn't respond to on this subject - https://www.eng-tips.com/viewthread.cfm?qid=196797 where the general opinion was 40 degrees was as high as you should go. FHWA did some large scale direct shear testing and got more than 50 degrees - FHWA Publication No.: FHWA-HRT-13-068...
I have a project where they want to construct a fire access road around the complex using pavers over permeable base. During construction they want to use the road for construction vehicles (without the pavers). I suggested using cement treated permeable base (it's 3 sack with all coarse...
I was going over in my head how to explain something to non-geotechnical engineers when I realized I didn't understand it myself (embarrassing). Non-plastic silts are, imho, the worst construction material, weak, erodible, subject to collapse - assuming you won't use peat as a construction...
We did some construction work (lost money). The public agency required a performance bond on our original bid which we obtained. We eventually had a change order for about 2/3s of the original cost that they didn't require a bond on (though our contract with the bonding agency mentions that we...
Back in 1977 my undergraduate soils professor mentioned that there was a hotel constructed on a mat foundation in Mexico City that had two lobbies. Once the building had settled 10 feet, they started using the upper lobby. Was he pulling our legs? Does anyone know what hotel that might have...
Does anyone have any suggestions for on-line continuing education classes?
I tried the Australian company (hit and miss) and CPE solutions (complete miss).
Thanks
Hi, Civil Engineer here, so sorry to ask a really basic question.
We have a differential pressure gauge to measure the difference in total head and static head in a pipe and hence get the velocity head - we're extracting polluted air from the subsurface. The gauge is calibrated for standard...
This is continued from the Pit Undperinning - Jacking or Shims (or none) thread
Hi PEInc
You bring up another issue that I've been mulling over - if you're using a trench box, when do you have to close off the ends of the box? There isn't anything in OSHA regs that directly address the issue...
I'm working on a site in California with a pretty big environmental concern (soil gas at 10 times the human health screening level on the other side of inhabited commercial structures from the source area (so presumably directly under the inhabited structures the soil gas concentrations are...
Several of us resigned from our former employer (hereinafter very large company or VLC)last week. We obtained legal advice prior to leaving and feel that we did everything by the book (took nothing with us, didn't solicit clients prior to leaving, used no insider knowledge of VLC's business...
I was just reading a report by one of my competitors for a job where they underbid me by 1/3 and must have essentially given the reporting away for free. It's a fine report.
But they only did Atterberg Limits testing for expansive clays (I assume because they did them in house). The PI results...
Does anyone know what went wrong with the South San Padre Island 31-story condominium tower - here's a video of it being imploded
http://www.youtube.com/watch?v=1IQUoZmtyOo
The news reports indicate that they had 14 to 16 inches of settlement under the center of the tower. The GE firm is in...
I work for a very large firm that requires its subcontractors to indemnify us against all errors except errors for which we are solely negligent. We require the subs to name us as additionally insured and we require that the insurance certificate include a waiver of subrogation (so in cases...
I have to give a presentation to the management of my company (we're in the 4500 person range) on geotechnical engineering. We're mainly an environmental firm, but we have around 60 geotechnical engineers. Of the geotechnical engineers, 20 do straight geotechnical engineering (everything from...
Does anyone have a reference for minimum lift thicknesses for vibratory compaction of road base (3/4 inch minus)? I have a contractor having trouble making compaction with a decent-sized vibratory compactor on virgin aggregate. I think his lift size (4 inches) is too thin and he's just bouncing...
I have a fairly fundamental question about pavement design which I'd like to get some input on. The CBR is conducted on a soaked sample of subgrade material at a specific density - the sample is compacted to whatever you're going to require in the field (say 100% standard proctor) and then...
I've been asked to opine on the long-term stability of a 0.5H to 1V cliff, 30-m high. From pictures, it looks to be formed out of weakly-cemented sand.
I'm told there are even higher vertical faces in the area, so I'm not too concerned. But other than carving block samples out of the face for...
