Infill Walls Research Articles

ANALISIS STRUKTUR DENGAN DINDING PENGISI DAN TANPA DINDING PENGISI PADA GEDUNG BERTINGKAT TERHADAP PERILAKU DINAMIK DENGAN METODE TIME HISTORY

This study aims to compare structural modeling with the addition of wall elements and without walls with the help of SAP2000 software. The method used in this study is time history analysis using the San Fernando groundmotion data. Based on the modeling that has been done, the participation of the variance mass has reached 90% for structures with walls in mode 278 while without walls in mode 243. The addition of walls in this study resulted in a decrease in the drift value. The average percentage of settlement of each floor is 40.12% for the X direction and 30.26% for the Y direction. The addition of walls can also reduce the period value of the structure, where the structure with walls has a period value of 1.0804 seconds while the structure without walls is 1 ,2016 sec. Keywords: Building Structure, Infill Wall, Drift, Time History Analysis

Out-of-plane seismic performance of bed-joint reinforced Autoclaved Aerated Concrete (AAC) infill walls damaged under cyclic in-plane displacement reversals

The infill walls made of Autoclaved Aerated Concrete (AAC), which is a lightweight, fire resistant and energy efficient material, provide effective insulation solutions for building types of structures and becoming more and more popular in earthquake prone regions. Although the number of experimental tests examining the seismic response of clay brick infills is extensive, the amount of prior research on infill walls built of AAC blocks is rather limited. Past research revealed that the use of bed-joint reinforcement is one of the promising solutions to improve the global seismic response of masonry walls by enhancing strength and displacement capacity. In this study, the out-of-plane (OOP) seismic performance of AAC infill walls with flat-truss and innovative cord-type bed-joint reinforcement is experimentally evaluated. Also, consideration is given to the prior in-plane (IP) damage, which was found to degrade the seismic performance of infills in OOP direction. For this purpose, three IP and four OOP, in total, seven experimental tests were performed on four full-scale AAC infill wall specimens. The test parameters were selected in such a way as to make it possible to parametrically compare the OOP performance of AAC infills with flat-truss and cord-type bed-joint reinforcements with unreinforced AAC infill walls, together with the effect of prior IP damage on the OOP response of unreinforced AAC infill walls. It was found that the use of innovative cord-type bed-joint reinforcement improved the OOP strength to a similar extent to what was obtained from the truss-type reinforced specimen. In terms of ultimate displacement and energy dissipation capacity enhancement, the specimen with cord-type reinforcement performed better. In addition, the damages formed due to IP cyclic displacement reversals up to 0.005 drift ratio, which is defined as the drift limit for buildings with brittle infill walls in certain design codes, resulted in a significant reduction in the OOP strength and stiffness properties of AAC infills. The theoretical OOP strength calculations were found to provide unconservative strength values for the IP-damaged specimens.

Influence of Masonry Infill Walls on the Seismic Assessment of Non-Seismically Designed RC Framed Structures

This paper examines how the decision to include (or exclude) masonry infill walls in the modelling of non-seismically designed RC framed structures can affect the results of the EC8-3 seismic assessment process. A frequently used macro-modelling technique for the simulation of infill panels within bounding RC members is first reviewed. A case-study application follows in which the seismic assessment of a sample structure is carried out, with and without considering the effect of its infill walls, using nonlinear static and dynamic analysis models. The obtained results are then discussed according to the applicable limit states’ performance requirements, and conclusions are drawn regarding the overall outcome. The study indicates that, when low and medium seismic input motions constitute the base demand for the assessment of older-type RC framed buildings, the protection provided to the RC members by the confined masonry infill panels should not be neglected. Moreover, it shows that the identification of the most likely collapse mechanism might also be significantly influenced by the modelling decision in question. As such, the default recommendation is to include masonry infill walls in the modelling of such structures.

Seismic performance of RC frames with self-centering precast post-tensioned connections considering the effect of infill walls

This paper presents the seismic performance evaluation of self-centering precast post-tensioned concrete (SCPPTC) frames with infill walls. The SCPPTC connection system consists of all-steel bamboo-shaped energy dissipaters (SBED) and prestressed tendons, which provide energy dissipation capacity and self-centering capability, respectively. Using modeling parameters calibrated with experimental tests, nonlinear numerical models of SBED, SCPPTC connection, infill walls, and 2D SCPPTC frames were developed in OpenSees, to compare the performance of the structures with different types of infill wall layouts. Nonlinear static pushover and incremental dynamic analysis (IDA) were performed to study the effect of infill walls on the overall response of SCPPTC frames, in terms of stiffness, strength, maximum interstory drift ratio,θmax, the maximum residual interstory drift ratio, θr,max, and the normalized post-tensioned force. Using the IDA results, the study also developed fragility curves and estimated the collapse margin ratios. The results demonstrated that the shear strength of the SCPPTC frame was improved from 4.19% to 12.2%, and the initial secant stiffness of the SCPPTC frame was augmented from 22.9% to 88.3% with increasing filling rate. The totally infilled SCPPTC frame (SCPPTC-ToI) exhibits a 19.86% lower θmax than that of pilotis-infilled SCPPTC frame (SCPPTC-PiI) under rare earthquakes, and the maximum prestress of SCPPTC-ToI was also 7.14% lower than that of SCPPTC-PiI. With the increase in filling rate, θr,max increased by a maximum of 120.45%. The pronounced soft layer led to the highest failure and collapse probabilities of SCPPTC-PiI among all SCPPTC frames at the same performance level.

Collapse capacity assessment of non-ductile open ground story reinforced concrete frame

It is a well-known fact that the absence of infill walls at the ground story, which is termed as “open ground story” may lead to a soft-story deficiency, especially in the case of non-ductile buildings. The previous severe earthquakes have shown that catastrophic destruction may occur in such a condition. Therefore, the seismic assessment of open ground story reinforced frames, where the effects of infill walls are incorporated, is of vital importance. However, the effects of infill walls are generally disregarded or considered indirectly in the seismic assessment procedures of the codes. This may mislead the actual condition of the open ground story buildings at different performance levels. This study aims to assess a non-ductile reinforced concrete frame with an open ground story regarding the collapse prevention performance level. The pushover and incremental dynamic analyses results are evaluated following the code limitations for collapse prevention. The results demonstrate the measure of misleading caused by the ignorance of infills at the upper stories while applying these code limitations.

Testing of Damaged Single-Bay Reinforced Concrete Frames Strengthened with Masonry Infill Walls

Despite achieving consensus and having current knowledge on the behaviour and contribution of masonry infill walls, there remain unresolved issues regarding their nonlinear behaviour as a method for strengthening existing reinforced concrete (RC) frames with effective modifications, primarily infills and the interconnection of infills and frames. The challenge for safely and economically designing frames with competent walls is to utilise the stiffening benefits while ensuring that the increased lateral forces and reduced drift capacity do not hinder performance. This study aims to investigate the potential of using masonry infill to strengthen previously slightly damaged RC frames. Experimental tests were conducted on previously slightly damaged RC frame specimens infilled with vertically hollowed-clay and solid-clay masonry units, connected to the frame elements using traditional methods (i.e., avoiding the use of modern composite materials). These strengthened infilled frame structures were subjected to constant vertical and cyclic lateral loading, which revealed improved stiffness, strength, and damping characteristics, enhancing their overall behaviour. As the main novelties, the study found that when damaged RC frames were strengthened with masonry infill walls, their performance resembled that of undamaged infilled RC frames. The strengthened infilled frame structures exhibited enhanced stiffness, strength, and hysteretic damping. The increase in stiffness was observed regardless of the type of masonry units and the strengthening technique employed. However, the improvements in strength and hysteretic damping were influenced by the specific masonry units, particularly their robustness, and the chosen reinforcement method.

Evaluating the effect of infill walls on seismic responses of post-tensioned self-centering concrete frames based on a new analytical model

This paper proposes a numerical model with the lump plasticity rotational springs for the simulation of post-tensioned self-centering (PTSC) concrete frames. The analytical connection model that is able to properly capture the joint responses and connection damage is incorporated in the rotational springs. The static and dynamic numerical results are validated against those obtained using the fiber-based structural model. Furthermore, the proposed numerical model is adopted in the seismic response prediction of PTSC frames with infill walls (IWs) and various energy dissipation components. Incremental dynamic analysis is performed through the scaling schemes based on Sa(T1) and PGA, and the effects of IWs and energy dissipators on the structural responses under different ground motion inputs are compared. The numerical results indicate a remarkable reduction in the inter-story drifts of the PTSC frames with IWs as compared to the bare frames under the same Sa(T1). Nevertheless, when subjected to ground motions with large PGAs, the damage of IWs would induce rapidly increased inter-story drifts in the lower floors, which may exceed the drifts of bare frames under the same earthquake intensity. This study highlights the accuracy of the proposed numerical model and the importance of considering IWs in the seismic response predictions of PTSC concrete frames.

Damage of Infill Masonry Walls due to Vertical Loads in Buildings with Reinforced Concrete Structure

Buildings are subjected to deformations of their reinforced concrete structure due to vertical loads that can lead, in certain cases, to the significant cracking of the unreinforced masonry (URM) infill walls, therefore requiring the development of specific knowledge of these types of deformations in order to minimise them. Aiming the evaluation of buildings with reinforced concrete structures subjected to vertical deformations, the mechanical characteristics of their infill masonry walls, as well as of their interface with the supporting concrete elements, are here analysed. The basic compression behaviour of brick masonry is assessed particularly through the previous analysis of a vertical compression test of a masonry specimen. The mechanical behaviour characteristics of the constituents (bricks, and mortar joints) are analysed to account for their influence on the compression behaviour of masonry infill, aiming particularly for the prevision of their cracking in case of vertical deformations of the supporting reinforced concrete (RC) elements. Based on that evaluation, the analysis of masonry walls subjected to vertical deformations of their supports is made through the assessment of the relevant characteristic behaviour of masonry wall-beam/slab assembly in case of vertical load. A general modelling approach of the behaviour of URM infills and the interaction with their supports is generally accessed. Finally, the preventive control of deformations of masonry wall-beam/slab assembly is discussed.

Strengthening of autoclaved aerated concrete (AAC) masonry wallettes with fabric reinforced cementitious matrix for in-plane shear and out-of-plane loads

Autoclaved aerated concrete (AAC) masonry is popularly used for the construction of infill and partition walls in the RC and steel-framed structures. However, past research highlighted that AAC masonry may exhibit poor performance during seismic events due to its low tensile capacity. In this study, the flexural and shear performance of AAC masonry was enhanced by using the fabric-reinforced cementitious matrix (FRCM). This strengthening scheme was applied in two modes: direct mode using anchor and sandwich method using adhesive mortar. These strengthening schemes were different from each other in the method of placing of the fabric. The experimental results showed that the proposed strengthening methods could improve the strength and ductility of the masonry under shear and flexural loads. The test results showed comparable strengths for both types of strengthening methodologies and either of two methods of fabric application may be chosen for the strengthening of AAC masonry, depending on the availability of materials and ease in construction. Moreover, the outcome of the conducted tests were compared with the respective theoretical predictions estimated using available analytical models and equations.

Damage Estimation of Full-Scale Infilled RC Frames under Pseudo-Dynamic Excitation by Means of Output-Only Modal Identification

To assess the health condition of structures and infrastructure during their service lives, continuous vibration-based monitoring represents a viable and cost-effective solution. Model updating and digital twins are increasingly adopted for damage detection. However, significant gaps and uncertainties in damage quantification still arise. This work presents original data from output-only modal identification tests on full-scale, two-storey reinforced concrete (RC) frames subjected to pseudo-dynamic loading to simulate seismic damage. The frames are tested with two masonry infill wall configurations with three-sided and four-sided boundary conditions, and the observed seismic damage is correlated to a damage scale. Output-only modal identification tests are performed before and after testing to catch variations in modal properties due to observed damage. Experimental data are used to build a refined finite element model able to reliably simulate the static and dynamic performance of the infilled RC frames before and after damage. The model allowed for the further assessment of the variation in natural frequencies of tested specimens at different earthquake intensities, the correlation of such variations to damage levels, and identification of the contribution of structural and non-structural components to the overall frequency variation.

Numerical simulation of RC-masonry infill wall system strengthened with textile reinforced concrete

Masonry walls are generally considered non-load-bearing elements in most concrete or steel-framed structures. Being a heterogeneous structure, the masonry system effectively enhances the strength and lateral stiffness of the overall panel when subjected to horizontal forces. But the recent unsatisfactory performance of unreinforced Masonry Infill Walls (MIW) during in-plane seismic loading has caught the attention of many researchers for the last few years. To overcome these detrimental effects, strengthening the MIW frame is considered the best procedure to enhance the horizontal load-carrying capability of the system. Numerous studies evaluating various parameters affecting the behaviour of MIW were conducted using Fiber Reinforced Cementitious Material (FRCM) as a strengthening material. This paper conducted a validation study that includes numerical simulation of the experimental research carried out at Wellington Institute of Technology in which nine 2:3 scaled single bay and single story Reinforced Concrete Frame with Masonry Infills (RCFMI) specimens strengthened with different fibers (basalt, carbon, and glass) of FRCM was tested under in-plane seismic/cyclic loads. The study went into detail on creating a numerical model replicating the non-linear structural cyclic behaviour of an infill wall bound by a reinforced Concrete frame and subjected to displacement-controlled in-plane lateral stress. The numerical analysis was performed in the Finite Element Method (FEM) programme ABAQUS using a streamlined micro-model approach. To simulate the non-linear behaviour of the masonry blocks and concrete, the Concrete Damage Plasticity (CDP) model was employed. The tested specimen was retrofitted with glass fiber grid diagonal bands, each with a width equal to 1/6 of the infill diagonal length. This analysis was used to create the numerical model. The validation demonstrated that the numerical model could faithfully simulate the behaviour and forecast the strength of masonry infill walls with RC frames. The findings of the observations are explained in the form of load–displacement hysteresis loops and excursion curves. The numerical results demonstrate excellent agreement with the experimental data, a significant impact of FRCM on the system's dynamic behaviour, and an improvement in MIW effectiveness with FRCM under cyclic loading is observed.

Review of different analysis and strengthening techniques of soft story buildings

Soft story buildings are vulnerable to seismic forces due to their weak lower levels, which can lead to significant damage or even collapse during earthquakes. Various analysis and strengthening techniques have been developed to mitigate this risk, each with its advantages and limitations. Objective of this study to provides a comprehensive overview of different strengthening techniques of soft story buildings, their effectiveness, and limitations. It also covers different strengthening measures such as global strengthening techniques (Adding of shear walls, Addition of infill walls, Adding of steel bracing, Wall thickening technique, Adding of wing wall /buttresses, Mass reduction, Base isolation) and local strengthening techniques (Jacketing of beam, Jacketing of column, Jacketing of the beam-column junction, Strengthening of individual footings). From the comparative study, it is observed that Jacketing techniques are one of the most popular and cost-effective local strengthening technique if only a few building components are flawed. Steel bracing required less work since the cost of the foundation may be reduced, interior framework receives significantly less weight. The findings can help engineers and researchers/practitioner to make informed decisions in selecting the most suitable retrofit strategy for a specific building.

Experimental Study of Structural Behavior of Banua Tadulako’s House for Earthquake Survivor of Palu

Huntap (Permanent dwelling) is a building intended for people whose houses are affected by disasters. The main requirement is that the building be proven to survive if an earthquake occurs around the Permanent dwelling located in the future.This research begins with the completion of the architectural drawing of the Banua Tadulako’s House (Rumbako) according to input from the Spatial Planning and Settlement Service of Palu City and the Directorate of Housing and Settlement Engineering Development of the Ministry of PUPR. The next process is the preparation of materials and equipment. Structural analysis using SAP 2000 software.Based on the analysis and simulation results, the following results are obtained: The stresses that occur on the surface of the wall do not exceed the allowable stress of the brick wall infill material, The cross-sectional capacity of the reinforcing steel is quite safe against the combination of loading applied to the structure. The basic seismic shear force of the structure capacity from the pushover analysis is 226 kN. More than the design earthquake force of 121 kN. Minimum connection details and truss structural elements have been calculated and qualify the requirements for strength and stress ratio.

Environmental assessment of a new building envelope material derived from urban agriculture wastes: the case of the tomato plants stems

PurposeDecarbonizing cities is one of today’s biggest challenges. In this regard, particular attention has been paid on improving the environmental performance of buildings. In this framework, this work consists in assessing the environmental impact of an innovative building envelope component derived from urban agriculture (UA) wastes. In fact, rooftop UA seems to be a possible solution to the rising food demand due to increasing urban demographic growth. Consequently, rooftop UA wastes need to be treated in sustainable ways.MethodsThis study aims to determine the carbon footprint and embodied energy of a new infill wall material, derived from UA wastes produced by a building rooftop greenhouse tomato crop, and evaluate the potential biogenic carbon that such by-product could fix temporally until its end of life. After an initial description of the manufacturing process of the new material, its carbon footprint and embodied energy have been calculated by means of the life cycle assessment (LCA) methodology according to the ISO 14044 and the ISO 14067 guidelines adapted to the analyzed context. In particular, the inventory analysis is based on data collected from the production of samples of the new material at the laboratory scale.Results and discussionThe results of the LCA indicate that, when the biogenic carbon fixed in the UA wastes is considered, a negative carbon footprint of − 0.2 kg CO2 eq. per kg of material can be obtained. Hence, it can be assumed that from a life cycle perspective the material is able to fix carbon emissions instead of emitting them. Specifically, for the considered scenario, approximately 0.42 kg CO2 eq./m2 per year could be sequestered. However, the crop area required to produce enough waste to manufacture a unit of material is quite high. Therefore, future studies should focus on individuate solutions to reduce the density of the new component, and also different urban crops with higher waste production rates.ConclusionsThe outcomes of the study put in evidence the potential of the new proposed infill wall component in fixing carbon emissions from UA, allowing to also compensate those relating to the production and transportation stages of the component life cycle. Moreover, producing by-products with UA wastes, hence temporally storing the carbon fixed by crops, may contribute to reduce the carbon cycles speed conversely to traditional waste management solutions, other than lower new raw materials depletion.

Investigation on the seismic performance of the masonry infill wall with damping layer joint

Aimed at improving the seismic performance of the traditional masonry infill wall (MIW), an innovative configuration called Damped Masonry Infill Wall (DMIW) is developed through subdividing the MIW horizontally and introducing damping layer joint (DLJ) into the wall. In order to verify the feasibility and the seismic performance of DMIW, the optimized material used as DLJ was determined among four types of materials via the shear-hysteretic test firstly. Then, a quasi-static test was performed to investigate the seismic performance of 1:2 scaled RC frame specimens with DMIW and traditional MIW, in terms of damage pattern, seismic parameters, shear deformation characteristics of DLJ. The results show that the modified asphalt waterproof (MAW) product, APF-500 (also labelled No.1 MAW in this study), is the optimized material used for DLJ among other three tested material. The expected working mechanism of DMIW that the shear deformation of the wall concentrates in the DLJs is able to be realized by using the optimized DLJ material. Also, it proves that DMIW is capable of presenting a prominent reduction of damage level and significant decrease of the lateral force and stiffness. It is anticipated that the detrimental effect of traditional MIW on the seismic performance of the frame structure can be avoided by adopting DMIW. Furthermore, a fitted equation of the relationship between the maximum shear deformation demand of DLJ and the lateral deformation of the RC frame is developed for determining the minimum thickness of DLJ in the case where DMIW has three masonry units.

Seismic fragility and risk assessment of self-centering wall structures with traditional and sliding joint infill walls

Self-centering (SC) precast wall structures have emerged as earthquake-resilient structural systems with excellent seismic performances characterized by low damage as well as negligible post-earthquake residual deformation. However, research on SC wall systems often ignores infill walls for simplicity, which results in difficulty to achieve an integrated resilient structural system. To fill this gap, this paper presents a comprehensive assessment of SC precast concrete wall structures with three different types of infill walls and compares the results with that without infill walls. The maximum inter-story drift, the peak floor acceleration, and the damage index of the considered systems at different seismic intensities are calculated through incremental dynamic analysis. The assessment is then expanded from fragility to risk by evaluating the probabilities of exceeding each potential limit state throughout the service life. Results show that, despite merely no damage to the SC wall itself, the integral system could sustain significant damage due to the damage to the infills attached. What’s more, with stronger infill walls, severer damage to the integral system is likely to be. Among the three infills considered in this study, the one with sliding joints performs the best from the perspective of damage, resulting in a smaller likelihood of 21%∼60% exceeding various damage limits than that of traditional infills. However, the sliding joint infill’s benefit in damage is at the expense of larger drift and slightly higher acceleration responses compared with traditional infills. It is concluded that the infills considered in this paper all have their drawbacks and new infills that combine the sliding mechanism (to reduce damage) and higher damping (to reduce drift and acceleration) are encouraged to develop an integrated resilient system.

Development of Fragility Curves for Reinforced-Concrete Building with Masonry Infilled Wall under Tsunami

A tsunami is a natural disaster that destroys structures and kills many lives in many countries in the world. A risk assessment of the building under a tsunami loading is thus essential to evaluate the damage and minimize potential loss. A crucial tool in risk assessment is the fragility curve. Most building fragility curves for tsunami force were developed using survey building damaged data. This research proposed a method for developing fragility curves under tsunami loading based on the analytical building model data. In the development, the generic building was a one-story reinforced-concrete building with masonry-infilled walls constructed from the structural index, popularly built as residential buildings along the west coast of southern Thailand. Three damage levels were investigated: damage in masonry infill walls, damage in primary structures, and collapses. The masonry infill wall was modeled using multisprings to represent the load-bearing behavior due to tsunami with a hydrodynamic pattern. The fragility curves were developed using the maximum likelihood method and considering the uncertainty due to masonry infill wall type, tsunami flow direction, and tsunami flow velocity. The developed fragility curve agrees well with the empirical tsunami fragility curve of a one-story reinforced-concrete building damage data in Thailand from the 2004 Tsunami. The developed fragility functions could be adopted for assessing tsunami risk assessment and disaster mitigation for similar structures against different tsunami scenarios in the future.

Effect of thermal expansion on three-dimensional reinforced concrete frames under high temperature

When exposed to high temperatures, reinforced concrete members undergo major changes in their properties which in turn affects their structural performance. Fire accidents in frame structures at local or global level may lead to collapse of structures. Structural fire has dire consequences like collapse of structures, colour changes, spalling of concrete and failure of essential elements. It is essential to study the conduct of reinforced concrete frame under thermal expansion in order to understand fire-induced collapse of concrete structures. This study observes how a three dimensional single-bay single-storey reinforced concrete frame is performed under thermo-mechanical analysis in ABAQUS (FEA). The paper aims to note the effect of slab and infill wall with respect to thermal expansion. The paper also discusses the main findings regarding the structural performance, structural leading conditions and structural stiffness of the reinforced concrete frame with slab and infill wall under thermal expansion. The results found that the infill frame has better stiffness and performs well under fire conditions.

In-plane seismic performance of different infill wall systems in ductile reinforced concrete frames

In-plane seismic performance of different infill wall systems in ductile reinforced concrete frames

Influence of mechanical properties of modified mortar on In-plane and Out-of-plane seismic performance of RC frame structure with infill walls

The reinforced concrete (RC) frame structures with infill walls are severely damaged under earthquakes. Therefore, enhancing the seismic performance of infill walls is essential to improve a building’s seismic resistance. Experimental investigations were carried out in this paper to enhance the mechanical properties of modified mortar using liquid nano-SiO2, polyethene acrylic acid (SA) emulsion, and polypropylene (PP) fibers as an additive. The results show that the flexural strength, compressive strength, tensile bond strength and shear strength of mortar along through joint were increased by 8.3%, 4.5%, 60.3%, and 60.8%, respectively, when adding 1% liquid nano-SiO2. The addition of SA emulsion improved the tensile bond strength but reduced the compressive strength and shear strength of the masonry along through joint. Adding PP fibers to mortar can improve the flexural and compressive strength but reduce masonry’s tensile bond strength and shear strength of the masonry along through joint. A finite element model of the infill wall-RC frame structure was established in ABAQUS, and the influences of modified mortar’s mechanical properties on in-plane (IP) and out-of-plane (OOP) seismic performance were analysed. The optimum percentage of liquid nano-SiO2 based on the simulation results was 1%. Compared with ordinary mortar, the initial stiffness of IP and OOP were increased by 8.45% and 13.3%, respectively, and the ultimate bearing capacity of IP and OOP were increased by 9.4% and 5%, respectively, when the containing of liquid nano-SiO2 was 1%. The IP and OOP initial stiffness and ultimate bearing capacity of the infill wall-RC frame structure with the SA emulsion mortar were lower than ordinary mortar. The IP and OOP seismic performances of the infill wall-RC frame structure with the PP fibers mortar were similar to ordinary mortar. The addition of nano-SiO2 emulsion improved the cement’s hydration performance and significantly enhanced the IP and OOP seismic performance of the infill wall-RC frame structure.