Comparison reinforcement design shear wall modelling planar and assembly in elevator shaft

Shear walls modelling as planar or assembly have different assumption in behaviour that will give different responses in forces. Shear wall planar modelling as individual walls which each wall was modelled as a vertical beam. Shear Wall assembly modelling as a combined unit to be represented by one beam element. The application of shear wall assembly is placed in elevator shafts in buildings or stairwell. [1]. In ETABS program, there are two types modelling shear wall are planar walls and wall assemblies. The analysis is based on three types of design section that are Simplified Compression (C) and Tension (T), Uniform Reinforcing and General Reinforcing. The purpose of this study is comparing the planar walls Simplified C and T with planar walls Uniform Reinforcing and wall assemblies Uniform Reinforcing. The conclusion for longitudinal reinforcement are, first, planar walls Simplified C and T is 40 to 96 % larger than wall assemblies, except pier P6 is 28 % smaller, second, planar walls Uniform Reinforcing is larger than 7 to 33 % wall assemblies Uniform Reinforcing, except pier P6 is 39 % smaller, third, the planar walls Simplified C and T, planar walls Uniform Reinforcing transversal reinforcement are 1 to 8 % larger than wall assemblies Uniform Reinforcing, except pier P6 is 51 % smaller.

HIGH-STRENGTH CONCRETE HOLLOW BEAMS STRENGTHENED WITH EXTERNAL TRANSVERSAL STEEL REINFORCEMENT UNDER TORSION / SUKTINĖS STIPRIOJO BETONO DĖŽINIO SKERSPJŪVIO SIJOS, SUSTIPRINTOS IŠORINE PLIENINE SKERSINE ARMATŪRA

Some bridges have to withstand high levels of torsion forces. As a consequence, box type beams are often the obvious solution. It could be possible that the balance of transversal to longitudinal torsion reinforcement is not fully reached. If the transversal reinforcement is somehow underestimated, the box beam needs to be transversally strengthened. From the various solutions, external transversal reinforcement is certainly one possibility. The investigation presented here aimed to study such solution. The authors tested four hollow beams under pure torsion. The level of the non balanced ratio between internal longitudinal and transversal torsion reinforcement was one of the parameters that were considered in this investigation. Other parameter was the existence or the no existence of external transversal strengthening reinforcement. The experimental results of the tests have shown the effectiveness of the use of the external transversal strengthening steel reinforcement to compensate the lack of balance of internal transversal to longitudinal torsion reinforcement with respect to various behaviour aspects, such as: increasing of torque strength, increasing of ductility, increasing of cracking torsion moment, and better distribution of cracking. Santrauka Kai kurie tiltai turi atlaikyti dideles sukimo jėgas. Tam tikslui dažnai naudojamos dėžinio skerspjūvio sijos. Gali būti, kad tarp sukimui atlaikyti naudojamos skersinės ir išilginės armatūros ne visada pasiekiamas tinkamas balansas. Jei skersinė sija armuota nepakankamai, dėžinio skerspjūvio sijas gali tekti papildomai stiprinti. Vienas iš įvairių galimų stiprinimo variantų – armavimas išorine skersine armatūra. Šiame straipsnyje pateikiama tokio stiprinimo analizė. Autoriai išbandė keturias grynojo sukimo veikiamas dėžinio skerspjūvio sijas. Vienas iš tyrimo parametrų – skersinės ir išilginės sukimo armatūrų santykio nesubalansuotumo lygis. Kitas parametras – išorinės skersinės stiprinimo armatūros buvimas arba nebuvimas. Eksperimentinių tyrimų rezultatai parodė stiprinti naudojamos išorinės plieninės skersinės armatūros veiksmingumą, kompensuojant vidinės skersinės ir išilginės suktinės armatūrų tarpusavio nesubalansuotumą. Efektyvumas buvo įrodytas tokias aspektais: padidėjusi sukamoji galia ir elastingumas, padidėjęs plyšių atsiradimo sukimo momentas bei geresnis plyšių pasiskirstymas.