Background
ASCE 7-10 Chapter 11 Seismic Design Criteria
11.1.2 Specifically excludes single family residences from the scope.
11.8.1 Specifically states that a structure assigned to Seismic Design Category E or F shall not be located where a known potential exists for an active fault to cause...
Hi,
Thank you... it's typically hollow stem ...
I appreciate the potential 'disturbance' factor ... however ... I can't understand why the disturbance would be so critical at the GWS interface and not so critical in the sample immediately beneath it (sampling interval ~ 2 1/2 feet). I would...
Hi,
My first boss (about 30 years ago) pointed out his observation that SPT values drop significantly in immediate proximity to the GWS only to increase again on either side. (For instance N values of 10, 5, and 12 at depths of 1, 6, and 11 (respectively) with groundwater around 6 feet)
Well...
Wow ... I thought I was the only one. I've performed consol tests - several times - on soils remolded to 90 or 95 - and have seen very little or no significant difference (sometimes the 95 moved more - that either shows the limitations of the test or the limitations on my ability to remold a...
"if law were actually practiced to the requirements that it meet the rules of common sense, we wouldn't need any lawyers."
Can I get that tatoo'd without a copyright infringement?
Your position that results of any other tests are irrelevant is in step with ASTM E 141 ... but unfortunately...
Understood TDAA ... I would not provide incorrect information. And I'm not lackadaisical, I evaluated the site based on blow counts in the native soils(Site Class D), based on the soft bedrock present(Site Class C), and based on the soft soils described for a site class E (because that profile...
First ... thanks everyone for taking the time to provide your input.
I plotted up the spectral response curve for each Site Class C, D, and E(ultimately a lesson in futility, but it made my nerdiness feel complete). From there I compared the equivalent base shear and simplified base shear (ASCE...
1)Is there a fundamental difference between how seismic waves amplify through an engineered fill vs. an in-situ soil profile? i.e. 30 feet of engineered fill on bedrock vs. 30 feet of alluvium (assume similar soils).
2)If you have an engineered fill 30' thick over bedrock, does that impact...
Thanks 'Corkster'! Sorry ... I forgot that part about the QC testing during mass grading. Yes, density tests and construction observation services were provided by an engineering firm during mass grading. But that has all been undone by an engineer with a drill rig, a scale, and an inability to...
Unfortunately, the investigation was for assessing the fill as placed against the project spec. Without a reference or a research project showing the variability in precision and accuracy is excessive ... it's just my humble opinion against his. Which just means we all lose.
Thanks for your...
I don't think I'll 'expose' myself ... what I'm talking about is a pervasive practice in my geographic location and my profession. Someone calls into question the compaction quality of a deep fill(i.e. greater than 5' let's say)... with or without distress to overlying improvements. The 'expert'...
I wish that were the case Big H (thanks for taking the time to post the reference, though, I appreciate that!). He doesn't correlate SPT to RD... he uses the SPT to obtain samples upon which he measures the unit weight (strike 1, right?) ... he then takes a bulk sample he's obtained from his...
70% of ASTM D 1557 to be exact!!!
I'm with you. I've been watching earthwork for over 30 years. If any of my tech's came in and said 70% I'd tell them they were using the nuc upside down. You and I both know 70 is rediculously low, but finding a study or reference that states that... good luck.
Unfortunately, it is the 'top-shelf' engineer with the 'gray beard' and the long list of projects and publications that is using unit weights obtained from SPT's and shelbys to characterize the site as 70% compacted. Really, 70%???
I've looked exhaustively for studies that support or refute...
Reading ASTM E141 it seems to me that when evaluating existing fills the standard practices of our industry are falling short. E141 indicates that location of and evaluation of the units being examined (dry density of the engineered fill) should be performed in exactly the same way as done for...
