Create a taxonomic system for defining nonstructural building components

PEER’s analysis operates only on well-defined facilities, where the definition includes geographic location, site soil characteristics, and structural and nonstructural components. Engineering parameters to define these features are familiar to most engineers, with the exception of nonstructural components. This hasn’t been a problem in the past, because nonstructural components were largely irrelevant to our models of seismic performance. That has changed with the development of PEER’s 2nd-generation performance-based earthquake engineering (PBEE-2) framework.

In PBEE-2, system performance is measured in human, operational, and economic impacts. One consequence of this change is that nonstructural components take on a new relevance. They produce much of the injury and economic loss in buildings, because they tend to represent the majority of building value and many are damaged at much lower levels of seismic excitation than are structural components. For example, in the 1971 San Fernando earthquake, losses at the Van Nuys testbed building were dominated by damage to tilework and bathroom fixtures. Not all tilework behaves the same, with the same damageability and repair cost, so we need to distinguish between different types of tilework, or between different varieties of bathroom fixtures, wallboard partitions, etc., and to communicate those differences clearly.

The present project will produce a taxonomic system for grouping nonstructural components using a scheme akin to that of RS Means. Taxonomic groups will be defined so that, within a taxon, capacity and unit repair cost can be reasonably assumed to be identically distributed between individual representatives of the group. Mathematically, we will define taxonomic groups D, so that others can later attach to each taxon a distinct and generally applicable damage function p(DM|EDP,D) and loss function p(DV|DM,D).

Base system on RS Means Co., Inc.’s Assembly Numbering System, with an additional numeric field to reflect differences in seismic vulnerability.

The PI has conducted analytical work related to UBPT bridge piers through prior research at Cornell University and has investigated such enhanced performance systems (that included using highly ductile fiber-reinforced concrete in hinge regions) through cyclic experiments and limited simulation work through an NSF Career project. The proposed PEER work focuses on finding methods to simulate these and other experiments using detailed and macro-models. While other experimental work related to UBPT bridge piers is or has been conducted in Japan (Ikeda) as well as at The University of California at San Diego (Priestley and Seible), the PI is not aware of other researchers conducting detailed simulation work related to UBPT bridge piers. Macro-modeling has been conducted for other self-centering construction practices such as the hybrid frame and precast walls (PRESSS Systems).

Year 7 will focus on the continued development of simulation approaches with further calibration of the models to more recent experiments (including those through PEER in Year 6). The application of the PEER PBEE Methodology to an alternate design for the I-880 testbed using the enhanced performance system and results from Year 6 will be carried out. In addition, collaboration with PEER researcher Mahin will be furthered for the analysis and development of the PBEE Methodology for enhanced-performances systems.

1. DM/DV and EDP/DM relationships for unbonded pot-tensioned bridge piers (including precast systems and systems that use high performance ductile cement-based materials)
2. Calibrated modeling approaches to simulate the cyclic and seismic performance of unbonded post-tensioned bridge piers. Modeling approaches will be through OpenSees and in the case of detailed continuum models not available in OpenSees, with the finite element code DIANA.

1. Sets of DM/DV and EDP/DM relationships for structural concrete bridge piers using unbonded post-tensioning and new materials.
2. A report on modeling approaches to predict and assess the performance of structural concrete piers that use unbonded post-tensioning and new materials.