Benefits of Lateral Strength in Terms of Residual Capacity

Abstract eng:
This paper investigates how altering design lateral strength may benefit the post-earthquake residual capacity of a structure. Lateral strength is a key design variable, yet its impact on residual capacity is not well-understood. Residual capacity quantifies the ability of an earthquake-damaged structure to resist collapse in subsequent earthquake events such as aftershocks, which impacts post-earthquake occupancy decisions such as building tagging. Here, the residual capacity is assessed for a set of 4-story modern U.S. reinforced concrete moment frames seismically designed with different design base shears, i.e. varying lateral strength levels. Other characteristics of the frames, such as deformation capacity, do not vary significantly. The collapse resistance of each structure in both intact and damaged states is assessed through incremental dynamic analysis, using a set of ground motions representative of California seismicity. Each structure’s residual capacity is assessed for multiple damage states, representing different levels of damage from the mainshock (first earthquake) event. Collapse fragility assessments are used to quantify a structure’s ability to resist further earthquake damage, based on residual capacity remaining in a structure after an earthquake. The results show that the stronger (above-code) buildings exhibit the same relative decrease in collapse capacity for a given damage state, but are stronger than the code and belowcode counterparts in both intact and damaged configurations. In addition, the stronger buildings are likely to experience less damage and, therefore, experience smaller reductions in residual capacity in a given shaking event. These results can be used to link building design strength to target desired post-earthquake outcomes.

• Export as: BibTeX | MARC | MARCXML | DC | EndNote | NLM | RefWorks
• Add to your basket