Document: NUREG-0800
Document ID: f387f4e9-c1e6-4266-aaf1-5834035426dc
Document Type: srp
Title: - Excavation and Backfill.  In meeting the requirements of 10 CFR Part 50, the
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1230/ML12302A004.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.5.4.5
CFR Part: 
CFR Title: 

Content:
uring excavation to preclude degradation of foundation materials and properties is described and referenced. In addition, the long-term behavior of the backfill subjected to any aggressive groundwater characteristics is evaluated. G. For sites where deeply embedded structures are involved, deep excavation techniques will likely utilize wall retaining systems rather than a sloped excavation of the soil. A description of the planned excavation technique(s) and design of the wall retention system with sufficient details is provided and it should be able to demonstrate that the excavation technique used will not significantly affect the surrounding soil properties that are relied upon in the analysis and design of the foundation and plant structures. Excavations, backfill, and earthwork are evaluated by the staff as follows: A. The investigations for borrow material, including boring and test pit logs, and compaction test data are reviewed and judged as to their adequacy. B. Laboratory dynamic and static records of tests performed on samples compacted to the design specifications are reviewed to ascertain that state-of-the-art criteria are met. The long term properties of the backfill material should be examined including consideration of the effect of chemical properties of groundwater. C. Analyses and interpretations are reviewed to ensure that static and dynamic stability requirements are met over the life of the plant. D. The description of the planned excavation techniques and the design of the wall retention system are reviewed to ensure they address all of the important aspects applicable to deep excavations. These include the type of wall (e.g., soldier pile and lagging walls, diaphragm walls, secant pile walls, soil nail walls), rock excavation methods if applicable (e.g., ripping, drilling, blasting), water control methods (e.g., rain, erosion, groundwater, dewatering), design of the particular wall being used (e.g., wall structure design for the various