As cities become larger and more densely populated the impacts of major earthquake events on city communities become more severe. Improving community resilience to earthquake events relies on the complex relationships that exist between different community stakeholder groups (citizens, businesses, community groups, emergency services, critical infrastructure providers, politicians etc.). This paper reports results from a major EU funded study (LIQUEFACT) that developed a tool for assessing community resilience to Earthquake Induced Liquefaction Disaster (EILD) events. The tool is based on a customised version of the UNDRR Disaster Resilience Scorecard for Cities. The paper reviews alternative approaches to measuring community resilience and describes the process used in the LIQUEFACT project to develop and validate the customised scorecard. The paper presents the results of a questionnaire survey to identify the best generic approach to measure community resilience and a series of semi-structured group interviews to define a range of specific metrics for assessing community resilience to EILD events; and the results of a validation workshop to assess the effectiveness and usability of the customised scorecard. The paper concludes that it is possible to develop a customised version of the UNDRR Scorecard at an appropriate level of granularity to support improved community resilience to earthquake induced soil liquefaction disaster events. The paper also presents key lessons that could assist those developing similar customised versions of the UNDRR scorecard for use in different geographical settings or against different disaster scenarios.

Due to the increasing population in the metropolitans, the construction of the high-rise buildings and shopping malls etc. has rapidly increased for last three decades. Therefore, especially in the city centers, the area of the construction sites has become very limited. Moreover, the requirements such as high bearing capacity of the soils beneath the skyscrapers and the parking area for the vehicles makes the application of the deep excavations essential. It is well-known that designing both safe and economical retaining structures in cohessionless soils such as sands and gravels or silty-clayey mixtures of them is still a challenging issue in geotechnical engineering discipline. Under that circumstances, the construction of two types of the retaining structures frequently comes into the minds: cantilever piles and well foundations. These retaining systems should be designed not only to be resist against failure but also to meet safety requirements for existing buildings and infrastructures near the site until the active forces, which are induced by the soil mass, are supported by the structural elements of the superstructures. In addition to this, the horizontal deformations along the retaining structures should be less than the limits defined by the specifications and the structural codes. In this study, the performances and costs of the both cantilever piles and well foundations in different excavation heights are compared parametrically. For this purpose, a benchmark sandy soil profile given in the literature and the retaining systems are modeled in 2D by using finite elements method. Furthermore, in order to determine the internal forces based reinforced concrete design and the unit costs; a well-known commercial software is used. The promising results of this study could guide to the design engineers in practice for selecting safer and more economical systems within engineering judgment.

The damage caused by seismic shaking and liquefaction-induced permanent ground deformation has conventionally been assessed as two separate problems often by different engineers. However, the two problems are inherently linked, since ground shaking causes liquefaction, and liquefaction-induced soil softening affects ground shaking. Modelling both problems within a single numerical model is complex for both the engineer and the software, and most finite element software only have the capabilities to address one of them. To improve the estimates of the seismic performance of buildings on liquefiable soil, a new sub-structuring approach is proposed called the macro-mechanism approach. This approach allows the soil-liquefaction-foundation-structure interaction to be considered in a series of sub-models accounting for the major nonlinear mechanisms of the system at a macro level. The proposed approach was implemented in the open-source finite element software OpenSees and then applied to a case study of a building where significant liquefaction- and shaking-induced damage was observed after the 1999 Mw 7.4 Kocaeli Earthquake. The case study building was also simulated using two different commercial software programs, the finite difference software FLAC, and the finite element software PLAXIS, by two different research teams. A comparison between the results from the macro-mechanism approach compared to full numerical models shows that the macro-mechanism approach can capture the extent of the foundation deformation and provide more realistic estimates of the building damage than full approaches since the FLAC and PLAXIS models consider elastic elements for the building.

This paper investigates the key parameters that influenced the settlement of a case study building on liquefiable soil in Adapazari (Turkey) during the 1999 Kocaeli earthquake. Ground movements in Adapazari caused large devastation, largely attributed to liquefaction of low plasticity silty soil layers underneath buildings on shallow foundations. The case study soil profile was well characterized by in-situ testing as well as laboratory tests from the Adapazari area. This allowed several different estimates of the building settlement to be obtained through different methods and through a variation in upper and lower bound estimates of the soil parameters. The different methods and different soil properties resulted in a wide range of estimates from 0.004 m to 1.6 m for the building settlement, compared to the observed in-situ value of 0.9 m. Even though the results were varied, the estimation of the liquefied strength of the soil appeared to be a key parameter for the settlement of the case study building. A detailed study with the PLAXIS finite‐element software and UBC3D‐PLM constitutive model, provided a consistent estimate of the final settlement of 0.9 m compared to the in-situ value. However, the limitation due to the enforced ‘undrained’ conditions during the dynamic phase of the analyses may have resulted in an inaccurate simulation of the pore water pressure and subsequently could have influenced the estimation of settlement. The modeling of the liquefaction settlements under free-field conditions was also considerably less than the re-consolidation settlements that were obtained through simplified procedures, suggesting that the re-consolidation settlement under the foundation was not modelled accurately. The present paper focuses on the assessment of the settlements due to earthquake-induced liquefaction as part of the research being conducted within the European project LIQUEFACT.