Study On Seismic Performance Of High-rise Structure Of Uncertain Layout Of Interior Floors Of Apartment

As the growing of economy and living standard of people, residential is being built taller and more diversified, duplex apartments have become the first choice of consumers. To meet the needs of different people, developers decide if the interior floors of apartment be remained in accordance with different people’s needs, which give rise to the uncertain layout of interior floors of different apartments. Uncertain layout of interior floors of different apartments may cause the inconformity of quality and stiffness of each floor that lead to vertical irregularity, which give rise to weak stories. Damage may turn up to weak stories that cause the disable and collapse of the whole structures, which is the reason of casualties and property losses. That is why the seismic performance of this kind of structures should be deeply studied. Little study about the uncertain layout of interior floors of different apartments has been published. A common-used high-rise wall-frame structures considering nine different layouts of interior floors of apartment were selected, static and dynamic elastic-plastic analysis by adopting Perform 3D were carried out, A new robustness index-stiffness based redundancy indexes, which evaluate robustness of structure in the way of stiffness, was carried out and used to analyse different structures of layout of interior floors of different apartments capacity and stiffness, based redundancy indexes, structural displacement, hysteretic energy and material damage under rare earthquakes were studied, and the effects of uncertain layout of interior floors of apartments on seismic performances of(super) high-rise building were extensively investigated. Seismic fragility curves were built for each structure, suggestions were then given for the design and use of this kind of structures.The main works and conclusions are as follow:(1) A common-used high-rise wall-frame structures considering nine different layouts of interior floors of apartment were selected, the following situations have been considered: 1) Removing interior floors of apartment evenly along the vertical side; 2) Removing the same quantity of interior floors of apartment unevenly along the vertical side. Static and dynamic elastic-plastic analysis by adopting Perform 3D were carried out, capacity and stiffness, based redundancy indexes, structural displacement, hysteretic energy and material damage under rare earthquakes were studied. As the research shows, the quantitative uncertainty of interior floors of apartments result in decrease in both capacity and stiffness with maximum inter-story drifts mostly 40.4% lower than original structure, respectively. As the uncertainty of positions of interior floors of apartment is growing with maximum inter-story drifts 39.5% mostly lower than structure with interior floors of apartments removed evenly, the lower the structural seismic performance.(2) A new robustness index-stiffness based redundancy indexes, which evaluate robustness of structure in the way of stiffness, was carried out. Stiffness based redundancy indexes fill the insufficient of the robustness index based on capacity and hysteretic energy.(3) Ground motion intensity parameter and structural demand parameters are important for studying the seismic performances of(super) high-rise buildings. In this paper, 19 ground motion intensity parameters, maximum inter-story drifts and material damages in shear walls were introduced. The four performance of correlation, efficiency, practicality and proficiency were evaluated to assess the most reasonable ground motion intensity parameter. Analysis results showed that high-rise structures are most sensitive to ground motion intensity parameter of velocity. SAavg, PGV and SVavg are mostly appropriate for reflect the seismic performance.(4) Maximum inter-story drifts, SAavg and PGV are introduced to build the seismic fragility curves of 9 high-rise building to study the seismic performances of structures in probability. As the analysis shows, the quantitative and position uncertainty of interior floors of apartments can both cause the decrease of seismic performances of structures, as the quantity of interior floors of apartment has drop to 50%, the probability of damage decrease more obviously, 1 times lower than original structure. irregular layout of interior floors of apartment can cause bigger damage probability than the regular ones. The discrete of seismic fragility curves for moderate damage and serious damage are bigger than that for basic intact and damage. The seismic fragility curves of SAavg is more conservative. SAavg is more appropriate for PGV for evaluating the performances of(super) high-rise building.