This work studies a new design procedure to account for accidental torsion in buildings subjected to seismic ground motions. The procedure does not require a design accidental eccentricity and it is based on a simple amplification of design parameters obtained from the corresponding model without accidental torsion. The objectives of the study are to present and to evaluate the torsion design proposed procedure. Based on representative low-rise, reinforced-concrete building models subjected to a bidirectional earthquake ground motion, several scenarios of accidental torsion were simulated using the Monte Carlo method. In the first part of the study, elastic analyses of simulated models were carried out to obtain the amplification factor value ( F at ). In the second part, nonlinear analyses were performed to evaluate the design proposal based on ductility demands. Main conclusions of the study are: mean values of ductility demands do not significantly change between the torsionally balanced (TB) system and the corresponding one with accidental torsion (TU with F at = 1.0). However, these mean values decreased about 18% for beams and 16% for columns when the torsion amplification factor ( F at = 1.2) was used in the TU systems. As for peak ductility demands, the unbalance due to accidental torsion leads to increments close to 42% for beams and 54% for columns. On the other hand, the torsion amplification factor F at = 1.2 reduces the peak values in 25%, approximately, for beams and columns of systems with accidental torsion. Main limitations of the study are: it is based on one bidirectional ground motion (with several incidence angles) and eight structural models.

中文翻译：

---

将地震意外扭转纳入建筑设计的新建议

这项工作研究了一种新的设计程序，以解决遭受地震地面运动的建筑物中的意外扭转。该程序不需要设计意外偏心，它基于从相应模型中获得的设计参数的简单放大，而没有意外扭转。该研究的目的是介绍和评估扭转设计建议的程序。基于受到双向地震地面运动的代表性低层钢筋混凝土建筑模型，使用蒙特卡罗方法模拟了几种意外扭转情况。在研究的第一部分中，对模拟模型进行了弹性分析，以获得放大因子值（ F at ）。在第二部分，进行非线性分析以评估基于延展性要求的设计方案。研究的主要结论是：在扭转平衡 (TB) 系统和相应的意外扭转系统 (TU 与 F = 1.0) 之间，延性要求的平均值没有显着变化。然而，当在 TU 系统中使用扭转放大系数 (F at = 1.2) 时，梁的这些平均值下降了约 18%，柱的平均值下降了 16%。至于峰值延展性需求，由于意外扭转造成的不平衡导致梁的增量接近 42%，柱的增量接近 54%。另一方面，对于具有意外扭转的系统的梁和柱，在 = 1.2 处的扭转放大系数 F 将峰值降低了大约 25%。该研究的主要局限性是：