A liquefaction case study of gently sloping gravelly soil deposits in the near-fault region of the 2008 M w 7.9 Wenchuan
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A liquefaction case study of gently sloping gravelly soil deposits in the near‑fault region of the 2008 Mw7.9 Wenchuan earthquake Yan‑Guo Zhou1 · Peng Xia1 · Dao‑Sheng Ling1 · Yun‑Min Chen1 Received: 14 April 2020 / Accepted: 18 August 2020 © Springer Nature B.V. 2020
Abstract The 2008 Mw7.9 Wenchuan earthquake in China caused widespread soil liquefaction and ground failures. A liquefaction case study of gently sloping ground at Yingxiu Town in the near-fault region is presented, which features its relatively thick deposits of sand-gravel mixtures, high soil stiffness, extremely intensive ground motion, large lateral spreading and severe damage of superstructure. The details of ground motion, site condition, field manifestations of liquefaction, subsurface soil profiles and field testing of shear wave velocities are presented. A conceptual binary mixture model is proposed to explain the gravel content effect on the stiffness and liquefaction resistance of gravelly soils. A preliminary liquefaction triggering evaluation method for gravelly soils is proposed by considering the gravel content correction of shear wave velocities based on the existing simplified procedure for typical sandy soils. The failure mechanism of the Baihua Bridge built at this site is explored, and the liquefaction-induced lateral spreading in down-slope direction might aggravate the failure process by imposing a large kinematic load on the piers besides the inertial forces transferred from the superstructure. Keywords Liquefaction · Gravelly soils · Sloping ground · Shear wave velocity · Lateral spreading · Baihua Bridge · Case study · 2008 Wenchuan earthquake
* Yan‑Guo Zhou [email protected] Peng Xia [email protected] Dao‑Sheng Ling [email protected] Yun‑Min Chen [email protected] 1
MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Institute of Geotechnical Engineering, Center for Hypergravity Experimental and Interdisciplinary Research, Zhejiang University, 866 Yuhangtang Rd., Zijingang Campus, Anzhong Bldg. B‑404, Hangzhou 310058, P. R. China
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Vol.:(0123456789)
Bulletin of Earthquake Engineering
1 Introduction The May 12, 2008, Mw7.9 Wenchuan earthquake caused widespread soil liquefaction throughout a vast area of 500 km long and 200 km wide. One salient feature of liquefaction manifestations was the ejecta of gravelly soils, which were mainly distributed around Chengdu Plain where geologic setting typically consists of surface Holocene clayey soils and the underlying relatively thick gravelly soils (Zhou et al. 2009; Cao et al. 2011; Zhou et al. 2018). The liquefaction consequences of gravelly soils show significant differences compared with those of typical sands, and less ground deformation (e.g., settlement) and fewer surface ejecta were observed (Cetin et al. 2002; Wilkinson et al. 2013; Khoshnevisan et al. 2015). Although gravelly soils are commonly regarded as unlikely to liquefy and are widely used in the hydraulic dams, land reclamations and embankment engineerings (Hatanaka et al. 1997),
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