Özet
This paper presents the results of an experimental investigation of wave-induced liquefaction in the case of multiple wave exposures. The experiments include also standard progressive wave cases as well, for comparison. One kind of sediment was used in the experiments: silt (d50=0.070 mm). Four scenarios were tested with multiple wave-climate exposures, including (1) multiple wave climates separated with “quiet”, no-wave periods, and (2) those with no interruptions between the consecutive wave-climate exposures, resembling a storm situation. It was found that the first strongest wave climate (i.e., the first wave climate, which is strong enough to cause liquefaction) of a multiple wave-climate sequence “secures” the onset of liquefaction, independent of prior wave exposures. It was also found that the wave exposures following the “liquefying” wave (even with stronger wave properties) do not liquefy the soil. The experiments further showed that, after the completion of the liquefaction-compaction cycle, the pore pressure may still build up when the soil is exposed to a new wave climate in the sequence with an even stronger set of wave characteristics (wave height and wave period). However, the accumulated pore pressure will not be large enough to liquefy the soil. Likewise, after the completion of the liquefaction-compaction cycle, or after exposures to not one but a number of waves, again, even with stronger wave characteristics, the pore pressure may not even build up at all. The experiments shed further light on the circumstances in the field under which (1) the seabed soil would eventually become liquefaction resistant (with a very large relative density), and those under which (2) it would remain loose, both of which have been revealed by field surveys. Furthermore, it was found that, in the case when the wave-climate exposures are uninterrupted, the dissipation of the accumulated pore pressure is quite slow when compared with the situation where the wave-climate exposures are interrupted with “quiet”, no-wave periods. The results have been explained in terms of physical processes involved. Also, implications of the results for practice have been discussed in detail.
| Orijinal dil | İngilizce |
|---|---|
| Makale numarası | 104307 |
| Dergi | Coastal Engineering |
| Hacim | 183 |
| DOI'lar | |
| Yayın durumu | Yayınlandı - Ağu 2023 |
Bibliyografik not
Publisher Copyright:© 2023 Elsevier B.V.
Finansman
TS acknowledges financial support from the National Natural Science Foundation of China (52271274, 51909076), the Key Project of NSFC-Shangdong Joint Research Funding POW3C (U1906230), the Fundamental Research Funds for the Central Universities (B200201064), the Key Laboratory of Ministry of Education for Coastal Disaster and Protection, Hohai University (202003, 202205), the China International Postdoctoral Exchange Fellowship Program (20170014). Likewise, BMS acknowledges Hohai University grant through the Overseas Expertise Introduction Project. BMS and VSOK would like to acknowledge the three-year (2020–2023) research program NuLIMAS: Numerical Modelling of Wave-Induced Liquefaction Around Marine Structures, funded through the ERA-NET co-fund MarTERA Program (Grant No. 728053) under EU Horizon 2020 Framework. For the NuLIMAS program, funding is also received from the German Federal Ministry for Economic Affairs and Energy (Grant No. 03SX524A); the Scientific and Technological Research Council of Turkey (TUBITAK, Grant No. TEYDEB- 1509/9190068); and the Polish National Center for Research and Development. BMS and VSOK also acknowledge ITU ARI TEKNOKENT for their ongoing support under the ITU ARI TEKNOKENT R & D activities. DRF acknowledges financial support from the Independent Research Fund Denmark (project SWASH: Simulating WAve Surfzone Hydrodynamics and sea bed morphology, Grant No. 8022-00137 B). In this context, we note the following, mainly inspired by the comments of one of the reviewers of the paper. First of all, the processes may be viewed within the framework of non-Newtonian rheology, particularly with regard to the stage where the soil is in the liquid state immediately after the onset of liquefaction and before the compaction process kicks in. We note that NuLIMAS, 2020–2023 (Numerical Modelling of Liquefaction Around Marine Structures), a research program funded by European Union (which some of the present authors, BMS and VSOK, are actively participating in), is in the process of developing a theoretical framework for the stage involving the liquefied soil and also the compaction, taking into consideration the rheological properties of the soil. Secondly, it is believed that, from the point of view of rheology, data from in-situ rheometer combined with pore pressure data would shed further light onto the understanding of the physics of various stages of the liquefaction-compaction process. In this context, it should be noted that potential independent tests using the same silt in a rheometer could be conducted, which would also shed light onto, for example, the thixotropic behavior of the soil, the rheological behavior in which a material becomes less viscous when subjected to shear stress, and then returns to its original viscosity when the stress is removed. For the latter, the reader is referred to the work of Toorman (1997), investigating the thixotropic behavior of dense cohesive sediment suspension and its modelling.TS acknowledges financial support from the National Natural Science Foundation of China (52271274, 51909076), the Key Project of NSFC-Shangdong Joint Research Funding POW3C (U1906230), the Fundamental Research Funds for the Central Universities (B200201064), the Key Laboratory of Ministry of Education for Coastal Disaster and Protection, Hohai University (202003, 202205), the China International Postdoctoral Exchange Fellowship Program (20170014). Likewise, BMS acknowledges Hohai University grant through the Overseas Expertise Introduction Project. BMS and VSOK would like to acknowledge the three-year (2020–2023) research program NuLIMAS: Numerical Modelling of Wave-Induced Liquefaction Around Marine Structures, funded through the ERA-NET co-fund MarTERA Program (Grant No. 728053) under EU Horizon 2020 Framework. For the NuLIMAS program, funding is also received from the German Federal Ministry for Economic Affairs and Energy (Grant No. 03SX524A); the Scientific and Technological Research Council of Turkey (TUBITAK, Grant No. TEYDEB- 1509/9190068); and the Polish National Center for Research and Development. BMS and VSOK also acknowledge ITU ARI TEKNOKENT for their ongoing support under the ITU ARI TEKNOKENT R & D activities. DRF acknowledges financial support from the Independent Research Fund Denmark (project SWASH: Simulating WAve Surfzone Hydrodynamics and sea bed morphology, Grant No. 8022-00137 B).
| Finansörler | Finansör numarası |
|---|---|
| China International Postdoctoral Exchange Fellowship Program | 728053, 20170014 |
| EU Horizon 2020 Framework | |
| Ministry of Education for Coastal Disaster and Protection | |
| NSFC-Shangdong | U1906230 |
| VSOK | |
| Bristol-Myers Squibb | |
| International Technological University | |
| European Commission | |
| National Natural Science Foundation of China | 52271274, 51909076 |
| Türkiye Bilimsel ve Teknolojik Araştırma Kurumu | TEYDEB- 1509/9190068 |
| Narodowe Centrum Badań i Rozwoju | |
| Bundesministerium für Wirtschaft und Energie | 03SX524A |
| Hohai University | 202003, 202205 |
| Danmarks Frie Forskningsfond | 8022-00137 B |
| Fundamental Research Funds for the Central Universities | B200201064 |