Title:
Behavior of Large Pile Caps Subjected to Column Uplift
Author(s):
Yasmeen Al-Sakin, Christopher Higgins, James Newell, and Kent Yu
Publication:
Structural Journal
Volume:
120
Issue:
6
Appears on pages(s):
123-135
Keywords:
anchor; breakout strength; experimental test; failure; highstrength threaded bars (HSTBs); pile caps; uplift
DOI:
10.14359/51739088
Date:
11/1/2023
Abstract:
The structural performance of four reinforced concrete pile cap
specimens anchored by widely used proprietary high-strength
threaded bars (HSTBs) and subjected to column uplift loads is
investigated. The specimens were full-scale replicas of in-service
foundations in terms of geometry, material properties, reinforcement details, and loading conditions. The study also included isolated pullout tests of HSTB anchorages. Two of the specimens were modified by increasing the embedment depth of the column anchor plate to assess effectiveness as a possible retrofit approach. Failure of all specimens was brittle without yielding of embedded reinforcing steel. Moreover, the ultimate pullout capacity of the anchors was not achieved in any of the specimens. ACI 318-19
provisions underestimated the concrete breakout capacity of all
specimens and were unable to incorporate the beneficial effects
of the column anchor plate modification as it only considered the
anchor embedment length and edge distance as critical parameters
for calculating strength.
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