Sediment Sampling Services

Added: Oct 20, 2015 2:25 pm Questions and Answers that do not affect the Scope of Work and are for informational purposes only.

1. For the geophysical testing (Atterberg, shear strength, vane shear), the typical ASTM protocol is to do that on undisturbed core segments. In a recent RFP from the Portland District, these tests were done on composited samples. The QBB PWS states the samples will be collected "undisturbed", but then leaves open the question of post-processing. Would you please provide additional clarification.
Answer: The intent is to obtain undisturbed core samples at all three locations. This is not a typical characterization for DMMP analyses. The engineering tests specified in the RFP require obtaining undisturbed, and not "composite" samples.

2. If these tests are to be conducted on undisturbed core segments, can we assume that each 1.5 segment of the cores is homogenous and contiguous? If that is confirmed, it should be possible to get three undisturbed sections from each of the 1.5 ft interval, and then use a portion of the core for logging and collecting grain size. If not, it would be then required to collect dual samples at each core/section to collect undisturbed sediments from one sample, and log and composite the second sample.
Answer: Yes, it should be assumed that each core sample is relatively homogenous and it should be contiguous. Typically, sonic core barrels allow retrieval of material in undisturbed, contiguous 5-10'' intervals, depending on the size of the casing. Dual samples should not be necessary, assuming enough core is obtained for the laboratory analyses. We do not want "composite" samples.

3. In our experience with past USACE dredged material characterization, the physical parameters in addition to grain size, shear strength and Atterberg limits also includes bulk density ASTM D-7263), specific gravity (ASTM D-854), and moisture content (ASTM D-2216). Other than ASTM D-2216 which is listed under Part 6 (with no call in the PWS), these other tests were not listed in the PWS. Please confirm that these tests are/are not needed.
Answer: We confirm that the other tests mentioned in the question are not needed. ASTM D-2216, is listed in the reference section but is not needed independently as a separate test because the material is already considered saturated.
4. In the attached figure, Sample Area 2 appears to be directly in a slip within C dock. Given the requirements currently in the PWS for a sonic drill rig, it may not be possible to get the large barge needed to support that equipment into that slip. While a SAP can acknowledge making an attempt to get in there, will there be flexibility in the Corps' plans to sample in the area between C and B dock?
Answer: Yes., drilling locations may be adjusted in the field in the area between C and B dock to accommodate the contractor's equipment.

Added: Oct 15, 2015 5:10 pm Sediment sampling services at the Quillayute Boat Basin in La Push, Washington