Post-liquefaction Reconsolidation and Undrained Cyclic Behaviour of Chang Dam Soil
Understanding and determination of post-liquefaction stress–strain behavior of sandy soils under monotonic and cyclic loading is essential to estimate the deformations that might occur in liquefied deposits under further loading. The undrained response of reconsolidated specimens under multilevel cyclic loading simulates the post-liquefaction behavior of soils under earthquake aftershocks and other cyclic loading conditions. In the present study, post-liquefaction reconsolidation and undrained behavior of medium dense silty-sand of Chang dam under multilevel repeated cyclic loading is explored. The soil deposit underwent severe liquefaction during the 2001 Bhuj earthquake. During the first round of loading (C0), the specimens were subjected to 50 cycles of cyclic loading at 0.4 mm amplitude (A) and 0.1 Hz frequency (f) and exhibited liquefaction. After C0, developed excess pore water pressure was allowed to dissipate, and specimens were allowed to reconsolidate. Reconsolidated specimens were then subjected to second round of cyclic loading, C1 (A = 0.4 mm, f = 0.1 Hz and N = 35), and this process was continued for C2, C3, and C4 loading rounds. Significant reduction in void ratio (e) was observed each time when specimens were allowed to reconsolidate after each round of undrained cyclic loading, thereby increasing the liquefaction resistance. The increase in liquefaction resistance on repeated loading was reflected in the cyclic stress ratio (CSR) calculated for every cycle for each level of cyclic applied loading. The inclination of the peak deviatoric stress envelope (instability line) for each round of loading was observed to increase with repeated reconsolidation and cyclic loading.
KeywordsPost-liquefaction Cyclic loading Reconsolidation Stress path Cyclic stress ratio (CSR)
Financial Support from IIT Gandhinagar is gratefully acknowledged. Any opinions, findings, and conclusions or recommendations expressed in this material are those of authors and do not necessarily reflect the views of IIT Gandhinagar.
- 1.Anbazhagan P (2009) Liquefaction hazard mapping of Bangalore, South India. Disaster Adv 2(2):26–35Google Scholar
- 2.Amini ZA, Trandafir A (2008) Post-liquefaction shear behavior of Bonneville Silty-Sand. In: Geotechnical Earthquake Engineering and Soil Dynamics, vol IV, pp 1–9Google Scholar
- 3.Arulanandan K, Sybico J (1992) Post-liquefaction settlement of sand-mechanism and in situ evaluation. Tech Rep NCEER 1(92):239–253Google Scholar
- 4.Dash HK (2008) Undrained cyclic and monotonic response of sand-silt mixtures. Doctoral dissertation, PhD thesis submitted to Indian Institute of Science, Bangalore in the Faculty of EngineeringGoogle Scholar
- 5.Finn WD, Bransby PL, Pickering DJ (1970) Effect of strain history on liquefaction of sand. J Soil Mech Found Div 96(SM6)Google Scholar
- 6.Hussain M, Bhattacharya D, Sachan A (2019) Static liquefaction response of medium dense silty-sand of Chang dam. In: 8th international conference on case histories in geotechnical engineering. Geo-Congress, Philadelphia, USA, March, 24–27, 2019Google Scholar
- 11.Lade PV (1972) The stress-strain and strength characteristics of cohesionless soils. Thesis Doctoral, University of California, BerkeleyGoogle Scholar
- 17.Sriskandakumar S, Wijewickreme D, Byrne PM (2012) Multiple cyclic loading response of loose air-pluviated Fraser River sand. In: Proceedings of the 15th world conference on earthquake engineering. Lisbon, September 24–28, 2012Google Scholar
- 23.Toyota N (1995) Post-cyclic triaxial behaviour of Toyoura sand. In: Proceedings of IS-TOKYO96, vol 1, pp 189–195Google Scholar