Testing and predicting the response of reinforced conrete shear walls retrofitted for recentering

Basereh, Sina; Okumus, Pinar; Aaleti, Sriram; Liu, Qingzhi

doi:10.1016/j.engstruct.2023.116384

Cited by 2 publications

(5 citation statements)

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“…The models of the post-retrofitted walls were similar to those of the pre-retrofitted walls, except that they did not have the zero-length section of strain penetration or the zero-length shear spring, as test results indicated that shear deformations were minimal in retrofitted walls. 5,6 Debonded reinforcing bars were explicitly modeled using corotational truss elements kinematically constrained to the wall at the point where debonding ended. This ensured that strains were distributed uniformly across the debonded height of the remaining reinforcing bars.…”

Section: Wallmentioning

confidence: 99%

“…Testing of retrofitted walls showed that buckling of steel plates can be mitigated by providing a gap between the steel plate and the top of the foundation. 5,6 The confined concrete model was modified accordingly. Nonprestressed (mild) steel reinforcing bars were modeled using the Steel02 material in OpenSees (Figure 5B), which is based on the Giuffre-Menegotto-Pinto steel material with isotropic strain hardening.…”

Section: Materials Modelsmentioning

confidence: 99%

“…The models were validated using the experimental results from 1:3 scale shear wall-foundation assemblies tested under quasi-static cyclic loading. 5,6 Three specimens were tested: one pre-retrofit and two post-retrofit walls. The pre-retrofit wall was not compliant with ACI 318-19 in terms of spacing of transverse reinforcement in the web, spacing of confining bars in the BEs, and extension of BE reinforcement to the foundation.…”

Section: Model Validationmentioning

confidence: 99%

“…The details of the test specimens and test results are published elsewhere. 5 In this paper, the model results are compared to the test results for model calibration and validation.…”

Section: Model Validationmentioning

confidence: 99%

“…(3) Wall edges are confined to prevent premature crushing of concrete at the rocking plane. The constructability and performance of the retrofit system have been investigated experimentally, 5,6 as has the constructability of the post-tensioning anchorage systems at the foundation level. 7 With the steps described above, the retrofit converts conventional RC shear walls into hybrid rocking, recentering shear walls that have been shown to have small residual displacements and reduced tension damage compared to conventional walls for new construction.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Lateral load response and collapse probability of reinforced concrete shear walls retrofitted for repairability

Okumus,

Basereh,

Aaleti

2024

Earthq Engng Struct Dyn

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This paper demonstrates the efficacy of a new reinforced concrete shear wall seismic retrofit method through a series of nonlinear static and incremental dynamic analyses. Unlike traditional retrofit methods, the method investigated aims to convert conventional walls into self‐centering walls whose behavior is governed by rocking and flexure. The retrofit involves creating a cold joint at the foundation–wall interface, cutting some reinforcing bars to allow rocking, adding external post‐tensioning to enable self‐centering, and externally confining wall toes to prevent concrete crushing. The retrofit was applied to two building archetypes, each with two different shear wall designs. The four walls were retrofitted by varying retrofit parameters (portion of the vertical reinforcement bars cut, and external post‐tensioning amount). Nonlinear static and nonlinear response history analyses were performed using experimentally validated, computationally efficient models that simulate walls with fiber‐based beam–column elements. Incremental dynamic analysis was used to create collapse fragility functions for pre‐ and post‐retrofit walls. The results show that the retrofit is effective when some vertical reinforcement bars are left uncut across the foundation–wall interface. The retrofit is more effective for walls with vertical reinforcement distributed across cross‐section as compared to walls with reinforcement concentrated near boundary elements and for walls with structurally efficient amounts of reinforcement as compared to walls with higher amounts of reinforcement. This is attributed to the larger amount of reinforcement bars cut in walls with concentrated reinforcement layouts or heavy reinforcement amounts, leading to a larger loss of strength, recovery of which requires larger amounts of post‐tensioning.

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Section: Wallmentioning

confidence: 99%

Section: Materials Modelsmentioning

confidence: 99%

Section: Model Validationmentioning

confidence: 99%

“…The details of the test specimens and test results are published elsewhere. 5 In this paper, the model results are compared to the test results for model calibration and validation.…”

Section: Model Validationmentioning

confidence: 99%