Seismic Performance of Shear Wall with CFST Columns and Encased Steel Truss

Abstract

A shear wall with concrete filled steel tube (CFST) columns and encased steel truss is a new type of shear wall. To determine the seismic performance of the new shear wall, an experiment was carried on a 1/5-scale model. Based on the experimental study, the load-carrying capacity, stiffness, ductility, hysteretic property, energy dissipation and failure phenomena of the model were analyzed. It shows that the seismic performance of a shear wall with CFST columns and encased steel truss has high bearing capacity, stiffness, energy dissipation capacity and good ductility. In addition, a numerical elastic-plastic finite element (FE) analysis of a shear wall with CFST columns and encased steel truss were carried out. The computation results were in good agreement with the test results. FE software, ABAQUS, was used to change the ratio of steel truss to steel tubes and normalized axial force. The influences of different parameters of shear walls were carried out.Keywords: CFST; encased steel truss; shear wall; seismic performance; experimental research IntroductionIn high-rise buildings, the shear wall is usually the main structural component that resists the lateral force. Shear wall with CFST columns is a new type wall developed in recent years (Han and Yang, 2007). Researches have been carried out by some scholars. Kang, T.H. -K et al. (2013) made a careful study of a steel plate shear wall, and found that a properly designed steel plate shear wall would have considerable energy dissipation capacity, ductility, and ultimate strength. Probst, A.D. et al. (2010) studied the composite flexural behavior of full-scale concrete-filled tubes without axial loads. Abolhassan (2001) investigated a steel plate shear wall with CFST columns. During his test, the CFST columns were basically in an elastic state and the specimen showed good ductility and energy dissipation capacity. Qian et al. (2012) conducted a low cyclic loading test on a shear wall with CFST columns. The test results showed that the shear wall had larger load-carrying and deformation capacities relative to the conventional RC wall. Wang et al. (2015) studied the seismic behavior of a lowrise shear wall with CFST frame and embedded steel-

Shear Strength Prediction for SFRC Shear Wall with CFST Columns by Softened Strut and Tie Model

“…Furthermore, a new calculation method based on the SSTM for the shear strength of SFRC shear wall with CFST columns, RC shear wall with CFST columns, and SFRC shear wall was established. Finally, the shear capacities of 24 low-rise shear walls were calculated and the calculated values showed a reasonable agreement with the available experimental results [2,4,9,10].…”

“…e web of shear wall was separated into a series of diagonal compression rhombic blocks by the intercrossing inclined cracks under gradually increasing lateral load. As the lateral load increased continuously, the concrete rhombic blocks reached ultimate compressive strength and the concrete in the web was crushed and spalled, resulting in obvious shear-dominant failure mode for the shear wall specimens in this paper and the literature [2,4,9,10]. e existence of steel tubes and steel fibers cannot change the ultimate failure mode of shear wall specimens.…”

“…Although the experimental design parameters of SFRC shear wall specimens, RC shear wall with CFST columns specimens, and SFRC shear wall with CFST columns specimens were different, the failure processes of shear wall specimens in this paper and the literature [2,4,9,10] are similar. Based on the experimental results, the failure process generally could be divided into four stages: initial cracking stage, main diagonal cracks forming stage, limit stage, and failure stage.…”

“…where α v is the calculation coefficient for shear capacity, α v � 0.97 + 0.2In(ξ), ξ is the confinement factor, ξ � α s f y /f c , f y is the yield strength of steel tube, f c is the axial compressive strength of concrete, α s is the steel ratio of CFST column, α s � A s ′ /A c ′ , A s ′ and A c ′ are the cross-sectional areas of steel tube and concrete, respectively, A sc is the total cross-sectional area of CFST column, and τ scy is the shear yield limit, τ scy � (0.422 + 0.313α 2.33 s ) ξ 0.134 (1.14 + 1.02ξ) f c . e load transferring mechanism of SFRC web under the combined action of compression, bending, and shearing is very complicated, which is similar to RC web in the literature [2,3]. In the SSTM, the shear strength of the web is assumed to be that of concrete compressive struts, and the concrete in the web can continue to withstand shear force after the tension ties yield.…”

“…First, theoretical analysis and experimental study [1][2][3][4] show that the CFST columns serving as boundary members can provide the effective constraint to reinforced high strength concrete (RHSC) wall, restrain the cracking development, and also bear part of transverse load after the RHSC wall deteriorates gradually, indicating that the RHSC shear wall with CFST columns can form double-channel seismic line and have favorable seismic performance. Secondly, the application of SFRC is a good way to enhance the seismic behavior of conventional shear wall structure, especially the RHSC shear wall [5].…”