1 BROOKHAVEN SCIENCE ASSOCIATES

CFAC Review

Thomas F. Joos, P.E.Civil/Structural Engineer

BNL Plant Engineering DivisionMay 8, 2007

NSLS-II Conventional Facilities Update

Geotechnical Conditions

2 BROOKHAVEN SCIENCE ASSOCIATES

Geotechnical Conditions (cont’d)

• Additional subsurface exploration conducted April 2007 (Advanced Conceptual Design Phase).

• Test borings taken at six (6) new locations.

• Cone Penetrometer soundings taken at three (3) new locations.

• Emphasis placed on western third of proposed site corresponding to westerly shift of building footprint.

3 BROOKHAVEN SCIENCE ASSOCIATES

Geotechnical Conditions (cont’d)

4 BROOKHAVEN SCIENCE ASSOCIATES

Geotechnical Conditions (cont’d)

• ACD Subsurface Exploration Program• Standard Penetration Tests (SPT)

– SPT continuous for first 10’ of depth.– SPT at 5’ depth intervals thereafter (to 47’ foot depth).– Soil samples collected from SPT tests.– Particle size (sieve) analysis to be performed on selected

samples.• Cone Penetrometer Tests (CPT)

– Cone penetration resistance continuous to 100’ depth.– Shear wave velocity measurements at 10’ intervals.

5 BROOKHAVEN SCIENCE ASSOCIATES

Geotechnical Conditions (cont’d)

• ACD Exploration Program Results (Preliminary)

• Standard Penetration Test (SPT) Results• SPT “Blow counts” ranged 16 to 50+ (In 2006, ranged 12 to 50+).• “Fill layer” ranged from ~3’ to ~9’ in depth (In 2006, ranged 3’ to 7’).• Underlying sand layers generally fine to medium brown sand with some

gravel & traces of silt. (Very similar to results from 2006 borings).

• Cone Penetrometer Test (CPT) Results• Shear Wave velocities ranged ~700 to 1000 feet per second (In 2006,

ranged 900 to 1100 fps).

6 BROOKHAVEN SCIENCE ASSOCIATES

Geotechnical Conditions (cont’d)• Conclusions

• 2007 data appears to be very consistent with the data obtained from 2006 explorations

• “Fill layer” appears to increase in thickness as you move west and south on the site.

• Conclusions/recommendations made in Geotechnical Report (CDR, Appendix D) are unaffected by latest data.

7 BROOKHAVEN SCIENCE ASSOCIATES

Geotechnical Conditions (cont’d)

• Conclusions (cont’d)• Settlement predictions remain unchanged (1” total/0.75”

differential at building column foundations).– Slabs on grade to experience settlements much, much less than

that predicted for building column foundations.– Type of soil present (granular) means settlements are immediate

(~90% of total occurring during building construction period)– Differential effects on slabs can be mitigated by construction

sequencing (thicker/heavier slabs first, build entire storage ring tunnel prior to adjacent experimental floor slab, etc.)

8 BROOKHAVEN SCIENCE ASSOCIATES

Geotechnical Conditions (cont’d)

• Path Forward• Further Investigation (Title I Design)

―Additional explorations (borings) to fully encompass the final building footprint.

―Test Pits―Further define obstructions in previously built-up areas.―Obtain samples for laboratory density tests (include results in

construction specifications)

• Incorporate construction sequencing requirements (differential settlement mitigation) into design/construction documents.