scholarly journals Assessment of ultimate drift capacity of RC shear walls by key design parameters

Author(s):  
Chanipa Netrattana ◽  
Rafik Taleb ◽  
Hidekazu Watanabe ◽  
Susumu Kono ◽  
David Mukai ◽  
...  

The latest version of the Standard for Structural Calculation of Reinforced Concrete Structures, published by the Architectural Institute of Japan in 2010 [1], allows the design of shear walls with rectangular cross sections in addition to shear walls with boundary columns at the end regions (referred to here as “barbell shape”). In recent earthquakes, several reinforced concrete (RC) shear walls were damaged by flexural failures through concrete compression crushing accompanied with buckling of longitudinal reinforcement in the boundary areas. Damage levels have clearly been shown to be related to drift in structures; this is why drift limits are in place for structural design criteria. A crucial step in designing a structure to accommodate these drift limits is to model the ultimate drift capacity. Thus, in order to reduce damage from this failure mode, the ultimate drift capacity of RC shear walls needs to be estimated accurately. In this paper, a parametric study of the seismic behaviour of RC shear walls was conducted using a fibre-based model to investigate the influence of basic design parameters including concrete strength, volumetric ratio of transverse reinforcement in the confined area, axial load ratio and boundary column dimensions. This study focused on ultimate drift capacity for both shear walls with rectangular sections and shear walls with boundary columns. The fibre-based model was calibrated with experimental results of twenty eight tests on shear walls with confinement in the boundary regions. It was found that ultimate drift capacity is most sensitive to axial load ratio; increase of axial load deteriorated ultimate drift capacity dramatically. Two other secondary factors were: increased concrete strength slightly reduced ultimate drift capacity while increased shear reinforcement ratio and boundary column width improved ultimate drift capacity.

2011 ◽  
Vol 243-249 ◽  
pp. 149-155 ◽  
Author(s):  
Zhe Li ◽  
Shao Ji Chen ◽  
Ye Ni Wang ◽  
Cui Ping Zhang ◽  
Jing Xu

The neutral axis change along with axial load ratio, load angle, section size etc. For the neutral axis of SRCLSC(steel reinforced concrete L-shaped column) is neither plumb with the plane that the moment work on, nor parallel with borderlines of SRCLSC section, it is difficult to get loading capacity and ductility of SRCLSC on biaxial eccentric loading. Based on the plane-section assumption, a method for the nonlinear analysis of complete response process for ductility of 15 SRCLSC..It include 36 sets for load angle, 6 sets for axial load ratio, 3 sets for concrete strength, 3 sets for the content of steel, 2 sets for steel style, 3 sets for stirrup ratio, 3 sets for steel location, 3 sets for section size, 3 sets for stirrup diameter about SRCLSC. The ductile behavior of L-shaped, with calculating 1068 loading conditions,are investigated. It concluded that axial load ratio, load angle, and ratio of the spacing of stirrups and longitudinal reinforcement’s diameter (s/d) are most important factors.


2011 ◽  
Vol 368-373 ◽  
pp. 28-32
Author(s):  
Zhe Li ◽  
Shao Ji Chen ◽  
Cui Ping Zhang ◽  
Shuai Zhang

Compared with reinforced concrete shaped columns, bearing capacity and ductility of steel reinforced concrete shaped columns are significantly improved, so it is with theoretical significance and practical application of value to research. Based on the plain cross section presume, with material T-section boundary calculation unit, 15 steel reinforced concrete T-shaped columns(SRCTSC) have made nonlinear full-rang numerical analysis. It demonstrates that the most adverse curvature ductility load angle of SRCCRSC is 180°.Loading angle ( ), axial compression ratio ( ), and the ratio of spacing and diameter of longitudinal reinforcements (s/d) are the principal factors in curvature ductility of SRCTSC subjected to biaxial eccentric compression. It include 36 sets for load angle, 6 sets for axial load ratio, 3 sets for concrete strength, 3 sets for the content of steel, 2 sets for steel style, 3 sets for stirrup ratio, 3 sets for steel location, 3 sets for section size, 3 sets for stirrup diameter about SRCTSC. The ductile behavior of T-shaped, with calculating 1068 loading conditions, are investigated. It concluded that axial load ratio, load angle, and ratio of the spacing of stirrups and longitudinal reinforcement’s diameter (s/d) are most important factors.


Author(s):  
Dae-Han Jun ◽  
Pyeong-Doo Kang

Reinforced concrete shear walls are effective for resisting lateral loads imposed by wind or earthquakes. This study investigates the effectiveness of a wall fiber element in predicting the flexural nonlinear response of reinforced concrete shear walls. Model results are compared with experimental results for reinforced concrete shear walls with barbell-shaped cross sections without axial load. The analytical model is calibrated and the test measurements are processed to allow for a direct comparison of the predicted and measured flexural responses. Response results are compared at top displacements on the walls. Results obtained in the analytical model for barbell-shaped cross section wall compared favorably with experimentally responses for flexural capacity, stiffness, and deformability.


2016 ◽  
Vol 10 (1) ◽  
pp. 334-348
Author(s):  
Cui Ji-Dong ◽  
Han Xiao-Lei ◽  
Yang Wan ◽  
Li Wei-Chen

In order to establish the relation between damage state and member deformation of the L-section RC shear wall, 216 FE models designed to meet the requirements of the Chinese codes were set up. The analysis fully considers the variation of parameters including axial load ratio and shear span ratio etc. According to the results, criteria of classifying failure modes of L-section RC shear walls are proposed. Failure modes are determined by shear-span ratio, moment-shear ratio and end columns' reinforcement ratio. Deformation limits corresponding to respective performance levels are put forward. Fitted formulas of calculating the limits are also presented. It is shown that the categorization criteria are reliably accurate in predicting failure modes. Deformation limits of a given L-section RC shear wall could be determined via axial load ratio and moment-shear ratio. The fitted formulas possess a satisfactory correlation with numerical results.


Author(s):  
M. J. N. Priestley ◽  
M. J. Kowalsky

Moment-curvature analyses of cantilever shear walls are used to show that yield curvature, serviceability curvature, and ultimate (damage-control) curvature are insensitive to variations of axial load ratio, longitudinal reinforcement ratio, and distribution of longitudinal reinforcement. The results are used to determine available displacement ductility factors for walls of different aspect ratios and drift limits. It is shown that drift capacity will generally exceed code levels of permissible drift, and that code drift limits will normally restrict, sometimes severely, the design displacement ductility factor.


2015 ◽  
Vol 37 ◽  
pp. 247 ◽  
Author(s):  
Hooman Farahmand ◽  
Mohammad Reza Azadi Kakavand ◽  
Shahriar Tavousi Tafreshi ◽  
Pooria Hafiz Hafiz

Experimental research activities and post-earthquake considerations have demonstrated that reinforcedconcrete columns with light or widely spaced transverse reinforcement are vulnerable to shear failure duringearthquakes. According to this point by using failure limit curve, we can assess the effective parameters in shearand axial failure of reinforced concrete columns in framed buildings. In the current study by flexural, shear andaxial springs which are used in series, shear and axial failures and important effective parameters have beenassessed, Besides 5,10 and 15 story models with different amounts of initial axial load ratio have been analyzedby nonlinear push-over analysis. The results of analytical models contain behavior of buildings based on differentinitial axial load ratio and different spacing of transverse reinforcement are compared


Author(s):  
Jun Zhao ◽  
Fuqiang Shen ◽  
Chenzhe Si ◽  
Yuping Sun ◽  
Lu Yin

AbstractExperimental investigation on seismic performance of RC shear walls reinforced with CFRP bars in boundary elements to enhance the resilience was presented which is expected for stable resistance capacity and small residual deformation. Six RC shear walls reinforced with CFRP bars as longitudinal tensile materials in boundary elements were tested under reversed cyclic lateral loading while subjected to constant axial compression with different axial load ratios of 0.17, 0.26 and 0.33, respectively. Two forms of stirrups were used for each axial load ratio, which were rectangular and circular stirrups in boundary elements. A reference specimen, ordinary RC shear walls, was also introduced to certify the excellence of CFRP bars. The test results indicated that the walls utilizing CFRP bars had small residual deformations and residual crack widths. Lower crack propagation height and larger concrete crushing region, bearing capacity and equivalent viscous damping coefficient (EVDC) could be observed with the increase of axial load ratios. The effects of stirrup forms on experimental results had a relation to the axial load ratio. When the axial load ratio was small, the shear walls with circular stirrups had better energy dissipation than that with rectangular stirrups at a given drift level, while the cumulative energy dissipation (CED) were similar. With the increase of axial load ratio, the walls exhibited similar energy dissipation at the same drift level, however, the shear walls with rectangular stirrups had larger CED.


2013 ◽  
Vol 718-720 ◽  
pp. 1923-1927
Author(s):  
Fu Lai Qu ◽  
Gui Rong Liu ◽  
Pei Yuan Tian ◽  
Lu Yang Qi

Based on the experiment of eight reinforced concrete T-shaped columns under low cyclic load, the factors which affect bearing capacity and seismic behavior, such as limb length, axial load ratio, stirrup ratio and the arrangement of longitudinal bars, etc., are analyzed. Tests results show that the bearing capacity of the columns increases, but the ductility is decreased with an increase of axial load ratio. The bearing capacity of T-shaped column increases when the web gets longer, while its deformability and ductility decrease. Besides, increase of stirrup ratio and longitudinal bars in the end of the web also have effect on the ductility of the columns.


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