Ductility Of Walls Research Articles

Effect of boundary element detailing on the seismic performance of reinforced concrete masonry shear walls

Laboratory tests demonstrated that reinforced masonry shear walls (RMSWs) can provide sufficient strength and ductility to be considered an efficient seismic force resisting system (SFRS) for mid-rise buildings. The ductility and overall seismic performance of shear walls were increased by providing confinement to the end zones of the walls to form boundary elements (BEs)., which enhanced the ultimate masonry compressive strain and curvature ductility of the walls. Regular stretcher blocks are commonly used in the construction of masonry boundary elements; however, they impose some constraints due to their geometrical characteristics. This study investigated the construction and testing of three half scale specimens of reinforced masonry shear walls with boundary elements (RMSWs+BEs) that were characterized by flexural dominance under reversed cyclic moment and lateral loading. In the lower story panel of a 12-story RMSW building, these walls constitute the plastic hinge zone, which is represented by a plastic hinge wall. In this study, C-shaped masonry units were used instead of stretcher units to construct BEs with different sizes and vertical reinforcement ratios. The findings of this work revealed that employing C-shaped masonry units to construct the BEs was effective in overcoming the construction limits imposed by stretcher units. Additionally, the results of this study demonstrated that when RMSWs+BEs are subjected to quasi-static reversed cyclic loading, they are capable of providing a high level of ductility with minimal loss of strength.

Study on Vertical Dowel Connections in Precast Walls

Precast concrete wall connections using dowels are becoming more popular and effective these days due to their ease of installation and cost. In this study, one-third scale models of slender and intermediate precast walls with dowel connections and monolithic concrete walls were tested experimentally and numerically under lateral cyclic loads. The experiments on precast walls and monolithic walls were conducted on a loading frame of capacity 20 T and the cyclic loads were applied until the failure of the wall specimens. The numerical studies on walls were carried out using Abaqus.cae software, and the same cyclic loads were applied. The responses such as ultimate load, displacement, cracking pattern, ductility, and energy dissipation capacity of precast walls were compared. The results obtained from the numerical investigation proved to be effective in simulating the actual behavior of the studied precast and monolithic walls, thereby reducing the burden of doing physical tests on a huge number of precast wall specimens.

Experimental study on the seismic performance of concrete shear walls partially replaced by MRPC

Shear wall structures are widely used in high-rise buildings, due to their satisfactory integrity and force transmission, thus superior seismic performance. However, due to insufficient material strength, non-standard construction, and the fact that some buildings have reached their design service life, many shear wall structures can no longer resist natural disasters such as earthquakes, nor can they meet the functional requirements. Therefore, it is of practical significance to reinforce shear wall structures and study their seismic performance. This paper uses the partial replacement method to reinforce and renovate concrete shear walls, using modified reactive powder concrete (MRPC) with excellent durability and toughness as the replacement material. The effects of different materials and different replacement positions on the seismic performance of shear walls were studied. A total of 5 shear wall specimens were designed and manufactured, including Specimen SW1 that did not reach the designed concrete strength, Specimen SW2 that met the original design strength, SW3 with the middle part of the wall was replaced by MRPC, and another two specimens that used ordinary concrete (SW4) or MRPC (SW5) to replace the two ends of the wall. Pseudo-static tests were carried out on the specimens and their seismic performance indicators such as bearing capacity, stiffness degradation, displacement ductility, and energy dissipation capacity were analyzed. Finally, finite element simulation analysis was also performed for the specimens. The results show that compared with the original design strength specimen SW2, the specimens SW4 and SW5, which used C45 concrete and MRPC to replace the two ends of the walls, effectively improved the bearing capacity, energy dissipation, and ductility of the shear wall. By comparing the mechanical properties of SW3 and SW5, it can be found that replacing the two ends of the shear wall can obtain better results.

Prediction of Failure Modes of Steel Tube-Reinforced Concrete Shear Walls Using Blending Fusion Model Based on Generative Adversarial Networks Data Augmentation

The steel tube-reinforced concrete (STRC) shear wall plays an important role in the seismic design of high-rise building structures. Due to the synergistic collaboration between steel tubes and concrete, they effectively enhance the ductility and energy dissipation capacity of conventional shear walls. To identify vulnerable areas prone to brittle failure and optimize the design, it is essential to develop a rapid method for identifying the failure mode of STRC shear walls. In this study, a fast identification method of STCR shear wall failure modes based on a Blending fusion model with Generative Adversarial Network (GAN) augmented data is proposed. The GAN is employed to address the issue of inadequate experimental data by generating new samples. This method combines classification boosting (Catboost), Random Forest (RF), K-Nearest Neighbors (KNN), and Least Absolute Shrinkage and Selection Operator (LASSO) to establish the Blending-CRKL fusion model to improve the prediction accuracy of the failure mode of STRC shear walls. The results reveal a significant improvement in the prediction performance of KNN, Backpropagation Neural Network (BPNN), RF, Light Gradient Boosting Machine (LightGBM), Catboost, and Blending-CRKL models after augmenting the training set with GAN. On average, the accuracy increased by 13%, precision increased by 81%, recall increased by 48%, and F1 score increased by 67%. The proposed Blending-CRKL fusion model outperforms the tested KNN, BPNN, RF, LightGBM, and Catboost models, achieving an accuracy rate of 97% in predicting the failure mode of STRC shear walls. Additionally, the stability and robustness of the Blending-CRKL model were validated, while the important features and value ranges of different failure modes were analyzed. This study provides a reference for the rapid identification of the failure mode of STRC shear walls.

ÇEVRİMSEL YÜKLER ALTINDA CFRP İLE GÜÇLENDİRİLMİŞ ÇELİK LEVHALI PERDELERDE ÇELİK LEVHA İLE CFRP ARASINDAKİ BİRLEŞİMİN AYRILMASININ DENEYSEL İNCELENMESİ

Steel plate shear walls, as an innovative lateral load resisting system, are widely used in the world. In this study, carbon fiber-reinforced polymer textile (CFRP) is used in order to increase load carrying capacity, ductility and energy dissipation of steel plate shear walls. A specimen of composite plate shear wall through epoxy bonding between two steel plates in a steel frame was prepared, and cyclic loading was applied. The finite element model of the steel plate shear wall without CFRP textile was prepared, and an in-plane static pushover analysis was conducted. The load-displacement curves obtained from the analysis of the model were compared with the results of the experimentally-obtained CFRP textile added specimen, and they were found to be in a good agreement. In conclusion, as a result of the addition of CFRP textile to the steel plate shear wall, it was observed that the carbon fiber reinforced polymer delaminated from the plate surface, and its contribution to the system behavior remained limited. Accordingly, it has been observed that in order to obtain the expected contribution, it is necessary to ensure that the steel plate and the textile must have full bonding and act as a composite material.

Study on seismic performance test and calculation method of recycled steel fiber reinforced concrete shear wall

SummaryRecycled steel wire is taken from used tires, and by procedures like mechanical cutting and friction treatment, it can be converted into industrial recycled steel fiber that meets precise criteria. Such green fiber may effectively limit the growth of fractures in concrete and diffuse the fracture energy of concrete when incorporated into concrete. An investigation of the effects of materials and horizontal reinforcement spacing on the seismic performance of shear wall specimens is presented in this research. The test and numerical simulation findings indicate that the RSFRC (recycled steel fiber reinforced concrete) shear wall's fracture is substantially narrower than that of a conventional shear wall and that the shear carrying capacity and deformation ductility of the shear wall have been greatly enhanced. The energy dissipation capacity of the RSFRC shear wall specimen with varying horizontal reinforcement spacing is significantly enhanced when compared to the conventional shear wall, and the ultimate displacements are reduced. RSFRC shear wall specimen has higher stiffness in the early stage, and the overall stiffness decreases slowly. With the decrease of fiber volume fraction of RSFRC shear wall in a certain range, the shear bearing capacity and stiffness of the model will decrease slightly, but the ductility will increase significantly. Compared with the RSFRC shear wall with fiber aspect ratio of 40 and 25, the bearing capacity and ductility of the two are close, but the RSFRC shear wall with low aspect ratio is slightly insufficient. When the axial compression ratio is in the range of 0.2–0.4, the horizontal shear capacity of RSFRC shear wall increases with the increase of vertical load, but the maximum horizontal displacement becomes smaller, and the model is damaged by compression. Using theoretical calculation, this work also creates the simplified calculation method and restoring force model for the bearing capacity of the diagonal section of RSFRC shear wall. The observed findings correspond well with the test hysteresis curve and may serve as a benchmark for future study. This study provides a new research direction for the seismic performance of RSFRC structures, as well as a solid theoretical foundation and promotion for future research.

Axial load behavior of unreinforced and reinforced hollow interlocking compressed stabilized earth block masonry walls

This study investigates the axial load behavior of unreinforced and reinforced hollow interlocking compressed stabilized earth block masonry walls. Sixty walls were constructed and tested under axial compression. The variables include block type (unreinforced and coir fibre reinforced), grout condition (ungrouted and grouted), channel blocks, reinforcement type (steel bars and bamboo splints) and configuration (vertical and mesh type). The results show that addition of coir fibres significantly increase the axial load capacity and ductility of walls, regardless of all other variables considered. Grouting of masonry cores increases the load capacity of unreinforced and fibre-reinforced walls (without bamboo/steel reinforcement), however slightly affecting the deflection capacity. The channel block had a detrimental effect on the load and deflection capacity of both unreinforced and reinforced walls. Bamboo/steel reinforced vertically significantly contributed to the axial load and deformability of walls, despite the presence or absence of channel blocks. Both bamboo and steel reinforced walls behaved in a similar manner; yet bamboo splints showing slightly lesser load and deflection capacity than steel. The axial load and deflection capacity of bamboo reinforced grouted walls are about 78.54% to 90.00% and 79.50% to 94.60% respectively as compared to steel reinforced counterparts. Bamboo/steel mesh reinforced walls with channel blocks exhibited better performance compared to corresponding specimens with only vertical reinforcement. However, the improvement was marginal, due to larger spacing between the horizontal reinforcement. Nevertheless, the presence of horizontal reinforcement greatly improved the failure behavior by restraining the buckling of vertical reinforcement. Overall, fibre and vertical steel reinforced grouted wall specimens without channel blocks (FSVRGMW) showed the best performance in terms of compressive strength. The design equations in MSJC-11 predicted the load capacity of unreinforced and reinforced masonry walls more conservatively. Finally, it can be stated that MSJC-11 recommendation of internally reinforced grouted walls must be treated as unreinforced walls, if no horizontal reinforcements was provided, is not reasonable.

Experimental study on the seismic performance of short shear walls comprising cold-formed steel and high-strength reinforced concrete with concealed bracing

Abstract This study investigates the seismic performance of a composite structure comprising cold-formed steel and high-strength concrete. Four short shear walls composed of cold-formed steel and high-strength concrete, namely, one specimen without diagonal bracing, one with angle-steel bracing, and two with lattice bracing, were designed for testing their low cyclic loading. The cracking load, ultimate displacement, maximum horizontal bearing capacity, failure process, hysteretic curve, and skeleton curve of the four specimens were obtained during the test. The results showed that the use of cold-formed steel-concealed bracing in the high-strength concrete short shear wall can effectively change the failure mode of the wall into bending shear failure with good ductility. An analysis of the energy dissipation of the four specimens revealed that the energy dissipation capacity and ductility of high-strength concrete short shear wall with cold-formed steel concealed bracing were improved, indicating that the use of cold-formed steel concealed bracing greatly improved the total energy dissipation capacity of high-strength concrete short shear wall. The calculated shear bearing capacity in the diagonal section of the wall with concealed bracing was compared with the measured one. Considering specifications, a formula for calculating the shear capacity in the oblique section of short shear wall with concealed bracing was proposed.

RC wall and steel side columns coupled structural system: Experimental and numerical investigations

The reinforced concrete (RC) wall coupled with steel side columns (SSC) using steel coupling beams were studied both experimentally and numerically. A 1/4 scaled 5-story test model was constructed and tested to failure under reversed lateral cyclic and constant axial loads. Test results proved that the coupling mechanism can be effectively realized in this unique coupled structural system involving only one wall pier. In order to reveal more seismic response characteristics in addition to the test results, numerical parametric studies were conducted based on the validated finite element modeling techniques. Results indicate the medium levels of axial load ratio and span-to-depth ratio of the steel coupling beam, or low level of wall aspect ratio, can lead to acceptable lateral load capacity and displacement ductility of the RC wall and SSC coupled structural system.

Experimental Study and Finite Element Modelling of Squat Shear Walls under Combined Cyclic Loads and High Axial Loads

Experimental observations on three reinforced concrete shear walls with small shear span-to-depth ratio (SDR) under combined high vertical axial load and horizontal cyclic loads are presented. The influence of high axial load ratio (ALR) on the failure mode, hysteretic behaviour, displacement ductility, shear strength and stiffness of the squat shear walls is investigated. In addition, a novel built-in strain gauges measuring system is employed for measuring the strain conditions in the reinforcements during the whole test process. Test results indicate that high axial load restrains the development of cracks and improves the shear load capacity, but that it also decreases ductility and energy dissipation and aggravates stiffness degradation. Concrete crush and out-of-plane buckling were observed in all specimens, resulting in the final failure of the specimens. According to the strain analysis, the section of the squat walls coincided well with the assumption of plane section under the condition of high ALR. With the increase of ALR, the depth of the compression zone of members increases, while the length of plastic hinge decreases. When the axial load is relatively small, the vertical and horizontal reinforcements provided almost equal contribution to the shear capacity of squat shear walls. However, under extremely high axial load, both vertical and horizontal reinforcements cannot provide full contribution to the shear capacity. The hysteretic behaviours of the tested shear walls were simulated by a cyclic softened membrane model (CSMM). Simulation results indicate that CSMM captured well the nonlinear characteristics of the squat shear wall under high axial load.

Response of RC shear walls with single and double layers of reinforcements subjected to in-plane cyclic loading

Reinforced concrete (RC) shear walls are primarily designed to resist lateral actions in buildings, in addition to carrying the vertical loads from above. Recent changes in the Australian concrete standard (AS 3600) enforces RC walls to have double layers of reinforcement in the horizontal and vertical directions to be considered as ductile walls, whereas RC walls with centrally placed single layered reinforcement are regarded as non-ductile walls. The in-plane behaviour of these RC shear walls under both in-plane lateral and vertical loads is complex as many parameters influence their lateral strength and deformity. To extend the knowledge on the performance of RC walls with single and double layered reinforcement, experimental testing followed by an in-depth data analysis was carried out in this study. The experimental study involved testing of two RC walls with the same percentage of reinforcement arranged either in single or in double layers under in-plane cyclic shear loading. The aim of the experimental testing was to investigate the reinforcement detailing effect between a single-layer and a double-layer configuration, while keeping other key structural parameters such as reinforcement ratio, concrete compressive strength, level of axial load, aspect ratio, and slenderness ratio constant. Experimental results revealed that the double layered RC wall possessed higher in-plane strength (by ∼30%) and displacement ductility (by ∼9.7%) than the single layered RC wall. To validate these findings, a database of the single- and double-layered RC walls using results from previous experimental studies was developed to compare the in-plane load capacities of single and double layered RC walls. Existing design provisions from the standards (AS 3600 and ACI 318–19) were employed to predict the in-plane load capacities of the single and double layered RC walls and compared with the experimental results of the database.

Self-centric cyclic resistance of reinforced concrete shear wall with Shape Memory Alloy: Numerical and experimental large-scale model

Over several decades, numerous researches have been routed to forge ahead in enhancing the building performance against dynamic loads. Nowadays, smart materials such as Shape Memory Alloy (SMA) have found profound impact in many applications of civil engineering. Nickel titanium alloy (NiTi) is one of the most famous among types of SMA. The current paper studies the behavior of shear wall, representing one of the most efficient lateral bracing element, structured by NiTi subjected to cyclic loading. Due to the unique characteristics of NiTi particularly in capacity to restore its original shape after unloading, the improvement in shear wall displacement recovery, wall ductility, hysteric behavior and inter-story drift ratio is presented. For this purpose, experiment study on large scale shear walls with aspect ratio 1.9 is conducted to investigate the effect of the intensity of NiTi on cyclic response. Two ordinary walls, as reference structures, and two hybrid walls are set up in order to perform the study. In addition, the validation of numerical simulation is examined by comparing its results with that obtained by the experiments and a pretty much in agreement is found. Hence, three-dimensional modeling by mean of ANSYS19 is extended to study the effect of NiTi length throughout the wall height on the shear wall response. The results showed that the existing of NiTi controls the cracks propagation and confines the majority in the lower third of the wall. Furthermore, for NiTi-wall, the study showed remarkable enhancement in recover capacity by 77 % and significantly increase in drift capacity ratio by 16.5 % relies on the NiTi ratio. Besides, some significant observations like the profile of wall curvature and energy dissipation are analyzed in this paper.

Seismic behavior of shear walls partially strengthened with UHPC in boundary element

Inspired by studies on shear walls reinforced with high performance cement-based materials, this paper explores the applicability of ultra-high performance concrete (UHPC) for improving the seismic behavior of shear walls. In this study, a novel shear wall partially strengthened with UHPC in the boundary element was developed, in which the UHPC was cast into the potential plastic hinge region of the boundary element. Partial application of UHPC can reduce construction costs and promote its use in building structures. To study the influence of distribution height and width of UHPC and axial load ratio on the seismic performance, six shear walls with a shear span ratio of 2.1 were tested under axial load and cyclic lateral load. The failure modes, lateral load-lateral displacement hysteretic behavior and ductility of the shear walls were also investigated. The experimental results indicated that the partial application of UHPC in boundary elements could effectively improve the performance of shear walls. Moreover, even if the volume ratio of UHPC was only 0.12, the shear wall partially strengthened with UHPC still showed good seismic performance under a high axial load ratio, indicating that this type of shear wall can be applied to the high seismic intensity and high axial load ratio regions.

Experimental research on the seismic behavior of brick walls reinforced with dry-connected steel plate frames

Masonry buildings often possess weak earthquake resistance, necessitating improvements in their seismic performance. This paper presents a novel approach to enhance the structural integrity of masonry walls by employing steel frames connected through bolts and welds. Experimental investigations were conducted on one unreinforced brick wall and four reinforced brick walls to examine their seismic behavior. The key parameters considered included the thickness of steel plates (3 mm, 5 mm, and 8 mm) and loading methods (reversed cyclic loading and monotonous loading). The experimental tests revealed that the proposed reinforcement method significantly enhanced the seismic performance of brick walls, particularly in terms of bearing capacity, ductility, and energy dissipation. Increasing the thickness of steel plates effectively improved the ductility of brick walls. The structural failure mode transitioned from shear failure to bending-shear failure due to the constraints introduced by the steel frames. The reinforced walls under reversed cyclic loading and monotonic loading exhibited similar failure modes, and the ductility of structures under monotonic loading was better.

Experimental and numerical investigations on interaction between reinforced‐concrete grid frame and ceramsite foam concrete infill

AbstractExperimental and numerical studies were conducted to investigate interaction between reinforced‐concrete grid frame (CGF) and ceramsite foam concrete (CFC) infill. In the experiments, compressive tests were performed on the CGF and RC grid frame filled with the CFC which forms a composite wall, namely CGFW. To investigate the mechanical properties of the CGFW and the interactions between the CGF and CFC infill, the failure modes, integral stiffness, local strains, and load distribution coefficients of the composite wall were analyzed. The experimental results indicated that the CFC infill could uniformly transmit loads and significantly improve the bearing capacity and vertical stiffness of the CGFW while reducing the ductility of the composite wall. The load distribution coefficients of the CFC infill were stable at 0.51 ± 0.06 before peak load and damage evolutions in concrete columns were effectively alleviated due to obvious interactions between the CGF and CFC infill. To evaluate the interaction mechanisms of the two, numerical analysis was carried out by changing the sizes of central grid, opening rates, and reinforcement ratios of the composite walls. The finite element model with plastic damage constitutive of concrete was calibrated by comparing the experimental results. The numerical results indicated that the interaction between the CGF and CFC infill was insensitive to changes in grid sizes, and the interaction between the two was significantly different with the same reinforcement method of frame beams and columns. In addition, the CFC infill played an important role in the stability of CGF as the opening rate significantly affected the mechanical properties of the CGFW, and a stable path of load transfer was the key factor to ensure the interaction between the CGF and CFC infill.

Parametric Studies on Seismic Performance of New Precast Braced Concrete Shear Walls under Cyclic Loading

A new precast concrete (PC) shear wall system with diagonal-shaped or cross-shaped concealed bracing was developed and experimentally validated, owning sufficient energy-dissipation capacity, in a previous study. Given that the seismic performance of such precast braced concrete shear (PBCS) walls is not comprehensively understood, this paper numerically investigates the influences of axial load ratio (ALR) and various reinforcement ratios (RRs) on the mechanical behavior of PBCS walls under cyclic loading. For this purpose, the numerical models based on the layered-shell element are developed to analyze the PBCS walls and validated regarding the deformation capacity of experimental results. A total of 156 PBCS wall models with different ALRs, longitudinal RRs of the boundary columns and bracing, and horizontal and vertical web RRs are established and tested under cyclic loading. It is concluded that the effects of bracing RR and horizontal web RR on the hysteretic responses are negligible and thus can be designed as the minimum suggested by the codes. However, the ALR, boundary column RR, and vertical web RR can significantly affect the lateral bearing capacity and displacement ductility of PBCS walls. In addition, the ALR limits for both types of PBCS walls are presented to satisfy the ductility requirements. Moreover, the simplified formulations regarding the bearing capacity and ductility of PBCS walls are proposed, respectively, which show good agreement with the numerical results. The outcomes of this research not only provide an in-depth understanding on the seismic behavior of the PBCS walls, but also promote the design code expansion and potential engineering application of such new types of PC shear walls.

Experimental investigations on the multi-layered SS316L wall fabricated by CMT-based WAAM: Mechanical and microstructural studies

In this research work, the cold metal transfer (CMT)-based wire-arc additive manufacturing (WAAM) process was used to fabricate a multi-layered wall using SS316L wire electrode. The wall was built with optimised CMT-WAAM parameters derived from a multi-variable regression analysis. The mechanical and microstructural characteristics of the multilayered wall were studied at the bottom, middle, and top regions. The macrostructure in all three regions of the wall indicates that the layers have completely fused together. The optical micrograph displays fine equi-axed dendrites in the bottom region, columnar grains with residual δ-ferrite in the middle region, and columnar dendritic structure in the top region. The tensile and impact test values of the bottom, middle, and top regions of the wall show that the values are comparable to their wrought counterparts. It was observed that the hardness value decreased with an increase in the build height. Scanning electron microscopy (SEM) analysis of the fractured surfaces of the tensile and impact test specimens showed dimples, indicating high ductility of the as-built wall and successful fabrication.

Experimental and numerical study on the seismic performance of T-shaped precast concrete shear walls with steel double tube connections

This paper proposed an innovative joint assembled by the high-strength screw rod with pre-buried steel double tube connections (SDTCs) in the T-shaped precast concrete shear walls (TPSWs). To study the seismic behavior of TPSWs with SDTCs, the low-reversed cyclic loading experiment and numerical simulation were carried out. In addition, parametric analysis was carried out to study the key parameters affecting the seismic performance of the novel joint, including the spacing of vertical SDTCs, the edge distance of vertical SDTCs, the axial compression ratio, and the shear span ratio. The test and simulation results showed that the spacing of vertical SDTCs had no significant effect on the carrying capacity of the new type of TPSWs. For the edge distance of vertical SDTCs, the smaller the edge distance, the higher the carrying capacity and the lower the ductility of the shear wall. Increasing the axial compression ratio will increase the carrying capacity but the effect is limited. Meanwhile, the ductility of the TPSWs will deteriorate. Increasing the shear span ratio will reduce the carrying capacity and improve the ductility. The shear span ratio is an important factor influencing the failure mode of the novel TPSWs. With the increase of the shear span ratio from 1.04 to 1.76, the failure mode varied in the order of shear failure, bending-shear failure, and bending failure. The final failure mode of the innovative TPSWs was the typical bending failure when the shear span ratio was greater than 1.52. Finally, the reasonable value range of the key parameters affecting the mechanical performance of the novel TPSWs was proposed, and the current codes can predict the bearing capacity of the novel shear walls which provide a basis for subsequent study.

Experimental Study on the Seismic Behavior of a Modified Adobe-Brick-Masonry Composite Wall with a Wooden-Construction Center Column

Damage to adobe constructions might occur due to a long wall and a lack of effective restraint in the middle of the wall, causing it to collapse under an earthquake. Aiming at these problems, a technology for improving the seismic performance of a modified adobe-brick-masonry composite wall with a wooden-construction center column is proposed. It uses modified mud, a wooden center column, steel-wire mesh, and nylon ropes to reinforce the wall. On this basis, four specimens of composite wall and one specimen of modified adobe wall were subjected to proposed quasistatic, cyclic in-plane loading tests to study their failure modes and seismic performance indicators. The results show that the failure modes of all walls were shear failure. The difference is that the modified adobe wall had horizontal cracks in the middle, whereas the composite walls were largely intact. Moreover, the composite walls relied on the modified mud to improve the seismic bearing capacity of each wall. They relied on the center column and the tie materials to form a second line of defense that would increase the wall ductility and collapse residual area. As a result, the phenomenon that caused wall damage and stiffness degradation was lessened.

Seismic performance of L-shaped short-leg shear walls with different concealed support materials

This paper reports a study of the effects of different concealed bracing materials on the seismic performance of short-legged shear walls and presents the results of low-frequency cyclic loading tests on three L-shaped short-leg shear walls—one wall without concealed bracing and the other two with concealed bracing materials of steel bars and SMA bars, respectively. The tests were aimed mainly at analyzing the effects of different concealed bracing materials on seismic performance indicators such as crack pattern, bearing capacity, ductility, hysteresis performance, stiffness, and energy dissipation of the L-shaped short-leg shear walls. The results revealed that their seismic performance with concealed bracing was better than without concealed bracing. The short-leg shear walls with SMA bar concealed bracing had the lowest number of cracks and the smallest crack width, and the effect of delaying the development of cracks was more evident. The short-leg shear walls with steel reinforcement and SMA-bar concealed bracing were better in bearing capacity, ductility, and energy dissipation capacity, with, respectively, 11% and 26.3% increase in ultimate load, 4% and 18.6% increase in ultimate displacement, and 12% and 28% increase in energy dissipation. It can be seen that setting concealed bracing effectively enhances the seismic performance of short-leg shear walls, and that short-leg shear walls with concealed SMA bar bracing have the most significant improvement in seismic performance.