Baseplate Rigidity and Anchorage Design

Volume 7, Issue 3, June 2022     |     PP. 79-110      |     PDF (2769 K)    |     Pub. Date: November 13, 2022
DOI: 10.54647/cebc56110    111 Downloads     82907 Views  


Longfei Li, Dr. Li Anchor Profi GmbH, Gustav-Stoll-Weg 7, 72250 Freudenstadt, Germany

The anchorage design with baseplates according to EN 1992-4 [1] and ACI 318 [2] postulates that the baseplates need to be sufficiently rigid, because the linear distribution of anchor forces is required for calculating the concrete failure resistance of anchor groups.
With the precondition that the baseplate is sufficiently rigid, a linear strain distribution under the baseplate is assumed in Eurocode [1] for calculating the anchor tension forces in the anchor group. But there are no workable provisions in [1] to check the required baseplate rigidity.
The research results about the stiffness criteria for rigid baseplate assumption in [3,4] confirm the statements in [5,6] that the linear strain assumption is unrealistic for normal baseplate thicknesses. That means, with normal baseplate thicknesses in the practice, the non-linear anchor tension force distribution will take place and has to be considered for the anchorage design. In this case, additional proofs to [1, 2] may be necessary in verifying the concrete failure resistance of anchor groups [3,4].
For anchor groups with narrow baseplate under shear load perpendicular to the long axis, there may be similar stiffness requirements on baseplate as for tension load.
In this paper, the rigid baseplate assumption for anchorage design is examined by calculation examples. The required thickness of baseplate to satisfy the linear strain assumption is studied by variation of tension load and bending moment. The proposed additional proof of anchor group resistance with non-linear anchor tension force distribution [3,4] is extensively verified by 40 test results. This additional proof is illustrated by design examples.
A realistic calculation model for baseplate under shear load is presented. A stiffness criterium for baseplate under shear load is proposed based on the calculation results of this model.

anchorage design, baseplate rigidity, anchor stiffness, tension, shear, concrete failure

Cite this paper
Longfei Li, Baseplate Rigidity and Anchorage Design , SCIREA Journal of Civil Engineering and Building Construction . Volume 7, Issue 3, June 2022 | PP. 79-110. 10.54647/cebc56110


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