ML19249A193
| ML19249A193 | |
| Person / Time | |
|---|---|
| Issue date: | 04/14/1979 |
| From: | Lipirski R Office of Nuclear Reactor Regulation |
| To: | Schauer F Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19249A194 | List: |
| References | |
| NUDOCS 7908210163 | |
| Download: ML19249A193 (2) | |
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APR 141979 MEMORANDUM FOR: Franz P. Schauer, Chief-
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Structural Engineering dr nch f
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f Division of Systems Safety FROM:
R. E. Lipinski Structural Engineering Branch Division of Systems Safety THRU:
D. C. Jeng, Section A Lesder p
Structural Engineering Branch Division of Systems Safety
SUBJECT:
PROPOSED CHANGE ON SEB POSITION WITH REGARD TO LOAD FACTOR FOR HYDR 0 STATIC PRESSURE IN STRUCTURAL DESIGN According to our present position in the SRP Sections 3.8.1, 3.8. 3, and 3.8.4 (Section 3.8.2 does not address this issue), the hydrostatic pressure due to ground water as well as buoyant forces is included in the dead load and in case of concrete structures a load factor of 1.4 is assigned. Since the lateral soil pressure is affected by the presence of water, it is my opinion that hydrostatic pressure due to ground water should be considered as a part of live load and the load factor assigned should be 1.7 instead of 1.4.
Our present position regarding this issue is consistent with the corres-ponding subjem t of the ACI-318 ACI-349 and ACI-359. As you know, many sections of the ACI-349.ed ACI-359 are based on the provisions of the ACI-318 and the resolution of my concern regarding proper assignment of a load factor to hydrostatic pressure' hinges on obtaining a formal interpretation of the issue from the pertinent ACI-318 Code Comittee.
In pursuance of this matter, I raised the question with the ACI-318 Code Comittee (Attachment 1) and received its fonnal response letter on the subject issue (Attachment 2). As you can see from the Code Comittee's
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i Franz P. Schauer, Chief letter, they have enddrsed my position.
I expect that the changes to the ACI-318 Connantary will be follow 2d by revision of the other two codes.
I am, therefore, proposing that our present position regarding the lateral pressure due to grounu water be changed and the.sertinent sections of the SRP be revised to reflect this change acco Jingly.
$. W' CW, R. E. Lipi ski Structural Engineering Branch Division of Systems Safety Attachments: As Stated cc w/ encl:
R. Mattson J. Knight A. Ashar G. Bagchi V. Noonan 4
SEB Members 34-i
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