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Base isolation is a widely accepted earthquake damage prevention technique. is method decouples the superstructure from the base by putting a flexible layer under each column, thereby elongating the time period of structures. Semi-base isolation (SBI) in double-skin structures is an effective technique to reduce the dynamic responses of structures due to earthquake motions, by utilizing the isolation devices in part of it instead of the entire base. is study presents a double-skin structure consisting of outer fixed base frames with shear walls that have been detached from the inner core with a minor gap. e inner core of the structure has been dissociated from the base using the elastomeric bearings. Seismic response of 10-story double-skin structure with inner isolated core was compared to that of inner fixed base core to consider the yielding and collapse probability of the structure using the incremental dynamic analyses (IDA). e results showed that the time period in SBI buildings can be adjusted with the use of coupling beams between the inner and outer frames. Also, the time period and interstory drift ratio are both reduced as more floors are given coupling beams. However, these coupling beams are the most effective at the topmost floors.

This paper aims to investigate liquefaction hazard assessment criteria available in practice which are obtained by geotechnical tests. In this study, developed indices for evaluation of liquefaction potential of susceptible soils under earthquake excitation were analyzed. From basic physical engineering indices resultant from in-laboratory investigations such as grain size distribution curves to the more sophisticated in-situ tests such as Downhole, standard penetration test (SPT), cone penetration test (CPT) and piezocone modified (CPTu) test, developed criteria were studied. Subsequently, liquefaction potential index (LPI) based-criteria for quantification of relationships among applicable in-situ tests were discussed. Finally, in reference to the data presented in this paper, appropriate methods such as geologic hazard mapping were suggested for further visualizing of coupled analyses with the aim of providing practical instrumentation of geological maps in liquefaction hazard assessment.

Base isolation technology is a popular and powerful isolation technology. This technique can greatly reduce the seismic response of the structure, so as to reduce the damage to the structure. Base isolation method decouples the superstructure from the base by installing a flexible layer under each column to reduce dynamic response in the earthquake and elongate the time period of structures due to its inherent flexibility. However, the long time period causes large displacement. In addition, base isolation devices are highly vulnerable due to uplift forces produced by lateral force resisting systems (LFRS). In this study, an adjustable structure with a new configuration, namely double skin semi-base-isolated (SBI) structure is presented to solve the above problems. The LFRS is omitted in the proposed SBI structure and the time period and displacement are reduced compared to the conventional base-isolated structure. The forcedeformation behavior of an isolator is modeled as bi-linear hysteretic behavior which can be effectively used to model all isolation system in practice. This study investigates the seismic performance of 10-story double skin SBI reinforced concrete (RC) structure under far-fault earthquake ground motion by numerical method. Results demonstrate that the SBI system is significantly adjustable with the use of RC coupling beams between the inner core and outer frames. By increasing or reducing the number of connected floors in the SBI system, dynamic behaviors of the SBI system can be changed. The adjusted structure can be created by adding and removing RC coupling beams at every arbitrary floor level.