Evaluation of gravel drains and compacted sand piles in mitigating liquefaction

Abstract

Liquefaction induced by earthquakes can cause major destruction to foundations and buildings, mainly as a result of excess pore water pressure generation and softening of the subsoil. Several remediation methods are performed that reduce the excess pore pressure, enhance the shear deformability of the soil, and fortify the soil. Two well-known methods-gravel drains and compacted sand piles-are discussed and compared in this paper. Some precisely prepared 1g shaking table tests are performed regarding these methods. Tests are done with and without the presence of an improvement method, and the accelerations, pore water pressures and settlements are monitored during the tests. The outcomes, judged against each other, reveal that compacted sand piles are more efficient than gravel drains in the case of liquefaction resistance and settlement of the subsoil during the shaking period. Nevertheless, after shaking, the efficiency of the gravel drains is ameliorated by the means of excess pore pressure dissipation.

Centrifuge modeling of offshore wind foundations under earthquake loading

“…19). It was found by Sadrekarimi and Ghalandarzadeh [49] that the densification technique was more efficient than stone columns for liquefaction resistance and settlement reduction during an earthquake. However, the compacted soil under the wind turbine maintained most of its initial stiffness and hence transmitted a large amount of seismic energy to the structure.…”

“…The technique of stone column, initially studied by Seed and Booker [54], is currently accepted as one of the most effective liquefaction countermeasures. The installation of stone columns can effectively improve the stiffness of soil and reduce the build-up of pore water pressure, and hence the associated settlement by quick drainage during and immediately after the earthquake [49]. The performance of stone column under seismic loading can be found in theoretical analysis, model tests [50,44,1] and case histories [43].…”

Engineering of Ground for Liquefaction Mitigation Using Granular Columnar Inclusions: Recent Developments

“…Al-Homoud and Degen [47] present an introduction to earthquake-resistant design of marine stone columns. Similar studies on different types of granular columnar inclusions include [51,28,52] on sand compaction piles [53] on prefabricated vertical drains [27,54,55] on gravel drains.…”

Numerical investigation of stone columns system for liquefaction and settlement diminution potential

“…However, in three dimensional analysis, there are at least 6 components of strain ratio tensor, which are calculated as shown below according to Eqs. (6)(7)(8)(9)(10)(11) …”

“…The main effects of stone column (drainage and stiffening) to mitigate liquefaction are investigated in varying soil condition by many researchers [4][5][6][7][8][9]. Although, these tests has provided valuable insight into stone column behavior to mitigate liquefaction during and after earthquake.…”