In your first stage, when you install the wood lagging, block it (with short, cut off pieces of lagging) snuggly to the rear flanges of the soldier beams. Note that this can reduce the lateral support of the soldier beam and adversely affect the allowable bending stress of the beams. When you...
ChiEngr, I assume that the drilled pier would be embedded much deeper than the 3.5 foot frost depth. Therefore, the pier's surface area below the frost depth should be several times greater than the surface area within the frost depth. The embedment length below the frost depth could have an...
I don't see any way of "drypacking" the top course of blocks. There is not any room to ram a damp sand/cement (drypack) mixture inside the top blocks. Why not just fill with grout?
There may be more to this problem than was indicated. How does the wall retain 20 feet of soil with only the small wall footing shown in Section 2-2? How many column footings need to be made larger? What is the column spacing?
Most inconsistent grout strength issues I see are with the sampling, varying mold sizes and shapes, storage on site, transportation, and test specimen prep. When I have low grout tests, I check the micropile design for the lower strength. Often I design for a lower grout strength but still...
Looking at this briefly, I would look at Model A and consider sheet piling with toe pins drilled into bedrock or a combi-wall of beams drilled into rock with sheets driven to rock. The toe pins or drilled-in combi-wall beams would provide passive resistance.
I would be interested in seeing a typical soil boring and the geotech report's recommended soil properties. What is the height of retained soil? Where is groundwater? Any surcharge loads behind the wall? Are you applying safety factor(s) to the soil properties or to the calculated embedment...
Not enough information given. WARNING: 8.5' excavation with an adjacent structure! Existing structure? Existing footing depth? Underpinning required?
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Rarely have I ever had to pre-load internal braces. However, see attached PDF.
www.PeirceEngineering.comhttps://files.engineering.com/getfile.aspx?folder=662eaf5f-d181-4d68-bca4-616074c26fb7&file=FHWA_Brace_Preloading.pdf
