Seismic damage to structures in the M s6.5 Ludian earthquake

The strong column–weak beam design philosophy in reinforced concrete frame structures: A literature review

“…Moreover, the suggested values of η C by some researchers summarized in Table 6 are still much larger than those stipulated in GB-50011 (2010), and only for RC frame structures of SG 1, the calculation of ∑ M B needs to be based on the actual reinforcement which considers the contribution of reinforcement in the slab; for RC frames of other SGs, the calculation of ∑ M B is still based on the designed reinforcement which does not consider the contribution of reinforcement in the slab. This situation indicates that structures built after 2010 probably still cannot completely meet the requirement of achieving the strong column–weak beam mechanism, which has been verified by some studies (Chen et al, 2016; Duan and Hueste, 2012; Lin et al, 2015). Duan and Hueste (2012) conducted both pushover analysis and dynamic time-history analysis on a typical 5-story RC frame model to evaluate the seismic performance of RC frames designed according to GB-50011 (2010) and the analysis results indicated that the RC frame has the potential to exhibit a soft first story failure mechanism.…”

“…Duan and Hueste (2012) conducted both pushover analysis and dynamic time-history analysis on a typical 5-story RC frame model to evaluate the seismic performance of RC frames designed according to GB-50011 (2010) and the analysis results indicated that the RC frame has the potential to exhibit a soft first story failure mechanism. After the Ms 6.5 Ludian earthquake in China in 2014, Lin et al (2015) and Chen et al (2016) conducted field investigations to evaluate the damage to buildings. A common failure mode was observed that most of the RC frames were badly destroyed due to the collapse of the first story, which indicated that the RC frames designed based on GB-50011 (2010) still failed to achieve the strong column–weak beam hierarchy.…”

“…However, column failures may cause progressive collapse of the entire structure and thus can lead to serious consequences. Investigations on the failed structures in great earthquakes have revealed that the collapse of RC frame structures was mainly caused by the failure of the columns (Chen et al, 2016; Li, 1994; Ye et al, 2008). To realize the beam-sway mechanism in an RC frame structure when subjected to seismic loading, the enforcement of a strong column–weak beam hierarchy based on the capacity design philosophy (Paulay, 1979) has been widely accepted as an effective way.…”

Irregularity of the Distribution of Masonry Infill Panels and Its Effect on the Seismic Collapse of Reinforced Concrete Buildings

“…In another post-earthquake building survey campaign, this time in Sumatra, the team identified the causes of failure of confined masonry structures to be shear column failure, longitudinal reinforcement buckling, and premature masonry collapse [11]. Likewise, the earthquake that affected Ludian Province in 2014 [12] provided an opportunity for the authors to corroborate that the confined masonry buildings designed, according to current standards demonstrated adequate performance, especially those with a uniform distribution of masonry.…”

Threshold-based evolutionary magnitude estimation for an earthquake early warning system in the Sichuan–Yunnan region, China

“…The high level of seismicity in this region is associated with its complex tectonic setting. The Sichuan–Yunnan region has experienced numerous destructive earthquakes that have caused extensive casualties and property losses; remarkable examples include the Ms 6.4 Ning’er earthquake 15 on 3 June 2007, the Ms 7.0 Lushan earthquake 16 , 17 on 20 April 2013, and the Ms 6.5 Ludian earthquake 18 on 3 August 2014. Of particular note is the Ms 8.0 Wenchuan earthquake, which occurred on 12 May 2008 and resulted in more than 69,000 deaths and financial losses reaching hundreds of billions of RMB 19 .…”