Effect of structural characteristics distribution on strength demand and ductility reduction factor of MDOF systems considering soil-structure interaction

Ganjavi, Behnoud; Hong, Hyun-Ki

doi:10.1007/s11803-012-0111-7

Cited by 22 publications

(14 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…observation is opposite to conclusions made by Ganjavi and Hao [38], where the concentric pattern was found to yield the lowest strength demand. The reason for this difference is attributed to different definitions of strength demand used in the two studies.…”

Section: Effects Of Design Lateral Load Patterncontrasting

confidence: 99%

“…For each storey in a given simulation, the peak storey ductility ratio was calculated as the maximum shear deformation divided by the yield deformation. The maximum value of the peak storey ductility ratios was used as the ductility demand of an MDOF building, as done by Santa-Ana and Miranda [13], Moghaddam and Mohammadi [37], and Ganjavi and Hao [38]. It should be mentioned that this ductility demand excludes the effects of the rigid body movements caused by the translation and rotation of the foundation and, therefore, can directly reflect the expected damage of the superstructure.…”

Section: Modelling Parameters and General Proceduresmentioning

confidence: 99%

“…In an analogy to R  for SDOF systems, Ganjavi and Hao [14,38] proposed that the base shear demand of nonlinear MDOF systems can be estimated from the base shear demand of their elastic counterparts through a ductility reduction factor given by:…”

Section: Sdof Ductility Reduction Factor R mentioning

confidence: 99%

See 2 more Smart Citations

Performance-based seismic design of flexible-base multi-storey buildings considering soil–structure interaction

Hajirasouliha

Marshall

2016

Engineering Structures

View full text Add to dashboard Cite

The version presented here may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher's version. Please see the repository url above for details on accessing the published version and note that access may require a subscription. AbstractA comprehensive parametric study has been carried out to investigate the seismic performance of multi-storey shear buildings considering soil-structure interaction (SSI). More than 40,000 SDOF and MDOF models are designed based on different lateral seismic load patterns and target ductility demands to represent a wide range of building structures constructed on shallow foundations. The cone model is adopted to simulate the dynamic behaviour of an elastic homogeneous soil half-space. 1, 5, 10, 15 and 20-storey SSI systems are subjected to three sets of synthetic spectrum-compatible earthquakes corresponding to different soil classes, and the effects of soil stiffness, design lateral load pattern, fundamental period, number of storeys, structure slenderness ratio and site condition are investigated.The results indicate that, in general, SSI can reduce (up to 60%) the strength and ductility demands of multi-storey buildings, especially those with small slenderness ratio and low ductility demands. It is shown that code-specified design lateral load patterns are more suitable for long period flexible-base structures; whereas a trapezoidal design lateral-load pattern can provide the best solution for short period flexible-base structures. Based on the results of this study, a new design factor R F is introduced which is able to capture the reduction of strength of single-degree-of-freedom structures due to the combination of SSI and structural yielding. To take into account multi-degree-of-freedom effects in SSI systems, a new site and interaction-dependent modification factor R M is also proposed. The R F and R M factors are integrated into a novel performance-based design method for site and interaction-dependent seismic design of flexible-base structures. The adequacy of the proposed method is demonstrated through several practical design examples.

show abstract

Section: Effects Of Design Lateral Load Patterncontrasting

confidence: 99%

Section: Modelling Parameters and General Proceduresmentioning

confidence: 99%

See 1 more Smart Citation

Performance-based seismic design of flexible-base multi-storey buildings considering soil–structure interaction

Hajirasouliha

Marshall

2016

Engineering Structures

View full text Add to dashboard Cite

show abstract

“…It is concluded that the lateral LP can considerably affect the required inelastic strength demands for both fixed‐base and SSI systems. This finding is in complete agreement with the results presented by Ganjavi and Hao and Lu et al for shear‐building structures considering SSI effects.…”

Section: Ductility Reduction Factor For Soil‐mdof Structure Systemssupporting

confidence: 93%

Effects of soil‐structure interaction and lateral design load pattern on performance‐based plastic design of steel moment resisting frames

Ganjavi

Gholamrezatabar²,

Hajirasouliha

2019

Structural Design Tall Build

Self Cite

View full text Add to dashboard Cite

Summary The effects soil‐structure interaction (SSI) and lateral design load‐pattern are investigated on the seismic response of steel moment‐resisting frames (SMRFs) designed with a performance‐based plastic design (PBPD) method through a comprehensive analytical study on a series of 4‐, 8‐, 12‐, 14‐, and 16‐story models. The cone model is adopted to simulate SSI effects. A set of 20 strong earthquake records are used to examine the effects of different design parameters including fundamental period, design load‐pattern, target ductility, and base flexibility. It is shown that the lateral design load pattern can considerably affect the inelastic strength demands of SSI systems. The best design load patterns are then identified for the selected frames. Although SSI effects are usually ignored in the design of conventional structures, the results indicate that SSI can considerably influence the seismic performance of SMRFs. By increasing the base flexibility, the ductility demand in lower story levels decreases and the maximum demand shifts to the higher stories. The strength reduction factor of SMRFs also reduces by increasing the SSI effects, which implies the fixed‐base assumption may lead to underestimated designs for SSI systems. To address this issue, new ductility‐dependent strength reduction factors are proposed for multistory SMRFs with flexible base conditions.

show abstract

“…Ceylan et al [33] estimated the strength reduction factor for prefabricated industrial structures having a single story, one and two bays. Ganjavi and Hao [34] studied the seismic response of linear and nonlinear MDOF systems subjected to a group of earthquakes recorded on alluvium and soft soils, considering different shear strength and stiffness distribution patterns. Kumar et al [35,36] investigated the influence of the frequency content of ground motions, as well as structural parameters and the level of inelasticity, on the inter-story shear and inter-story drift demands in frames designed according to Eurocode 8.…”

Section: Literature Reviewmentioning

confidence: 99%

Strength or force reduction factors for steel buildings: MDOF vs SDOF systems

Reyes‐Salazar¹,

Llanes-Tizoc²,

Bojórquez³

et al. 2017

J. vibroeng.

View full text Add to dashboard Cite

The nonlinear seismic responses of steel buildings with perimeter moment resisting frames (MRF), modeled as complex 3D MDOF systems, are calculated and the ductility demands, ductility reduction factors and the force reduction factors (), are studied. Equivalent 3D models with spatial MRF, two-dimensional models, and equivalent SDOF systems (SD), are also considered. Results indicate that the global and local force reduction factors significantly vary from one structural representation to another and that they are much larger for the SD models. One of the reasons for this is that, although there is equivalence between the SD and MDOF models, the dissipated energy and the number of incursions in the inelastic range are significantly larger for the SD models. In addition, while for the SD models total plasticization occurs, for the SAC and EQ models, even for significant yielding, plastic hinges are developed only in a relatively small number of structural members; therefore, using the factors of the SD models may be conservative. According to the results obtained in this research for the more realistic representation of the steel building (3D), the value of 8 suggested in many codes for the factor for ductile MRF cannot be justified. It is only justified for the SD systems. The implication of this is that non-conservative designs may be obtained if so large value is used. More transparence is needed in the codes regarding the magnitude and the components involved in the factor.

show abstract

Effect of structural characteristics distribution on strength demand and ductility reduction factor of MDOF systems considering soil-structure interaction

Cited by 22 publications

References 24 publications

Performance-based seismic design of flexible-base multi-storey buildings considering soil–structure interaction

Performance-based seismic design of flexible-base multi-storey buildings considering soil–structure interaction

Effects of soil‐structure interaction and lateral design load pattern on performance‐based plastic design of steel moment resisting frames

Strength or force reduction factors for steel buildings: MDOF vs SDOF systems

Contact Info

Product

Resources

About