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
JohnnyB, can you ask the structural engineer for unfactored service loads instead of factored loads. You will need service loads if you need to calculate settlement. This is for a building, not a highway. IBC has a different ASD formula than AASHTO/FHWA.
Look for a download of FHWA-SA-97-070...
Geoluk, underpinning should not be done in multiple lifts (i.e., underpinning the underpinning). Underpinning in multiple lifts compounds the possibility of problems and settlement ( 2 lifts, double risk, 3 lifts, triple risk, etc.). Underpinning should be performed using hand excavation, not a...
Seems to me you need a written agreement from the neighbor stating the maximum future depth of any dredging. Then design your wall for that depth or maybe even deeper.
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I would not consider that a rubble stone wall. What is the condition of the brick wall that is sitting on the single layer of big stones? How thick is the concrete on top of the stones? I have had a couple of projects where the rubble stone wall was in such bad shape, we removed it in sections...
You apply the various driving forces (wind, live load, hydrostatic, seismic, etc.) to the structure with their appropriate, individual, load factors (LF > 1). When checking stability (overturning and sliding), one of the resisting forces is the dead load of the footing but, in LRFD design, you...
