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The research described in this paper investigates the seismic behaviour of lightly reinforced concrete (RC) bearing sandwich panels, heavily conditioned by shear deformation. A numerical model has been prepared, within an open source finite element (FE) platform, to simulate the experimental response of this emerging structural system, whose squat-type geometry affects performance and failure mode. Calibration of this equivalent mechanical model, consisting of a group of regularly spaced vertical elements in combination with a layer of nonlinear springs, which represent the cyclic behaviour of concrete and steel, has been conducted by means of a series of pseudo-static cyclic tests performed on single full-scale prototypes with or without openings. Both cantilevered and fixed-end shear walls have been analyzed. After validation, this numerical procedure, including cyclic-related mechanisms, such as buckling and subsequent slippage of reinforcing re-bars, as well as concrete crushing at the base of the wall, has been used to assess the capacity of two- and three-dimensional low- to mid-rise box-type buildings and, hence, to estimate their strength reduction factors, on the basis of conventional pushover analyses
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... De hecho, la alta redundancia de tales estructuras tipo caja da como resultado picos de tensión más bajos y menos concentrados que los experimentados en pórticos de hormigón armado tradicionales; además estos últimos presentan trayectorias limitadas para la transferencia de gravedad y de carga sísmica. [13] Sin embargo, este mecanismo de resistencia (comportamiento tipo caja) solo se garantiza si están presentes las conexiones adecuadas entre los paneles verticales adyacentes y entre los paneles y las losas del piso. ...
... Según indican Brunesi et al [13] aún no se ha logrado un consenso unánime sobre un procedimiento único para seleccionar y escalar acelerogramas para obtener un conjunto de registros estándar, mientras que numerosos trabajos de ...
... Estas últimas también presentan limitadas trayectorias para la transferencia de gravedad y carga sísmica. [13] Los resultados reportados en este trabajo indican que el uso de paneles multilaminados en estructuras de poca altura (ensamblados con un refuerzo adecuado en las conexiones entre paredes ortogonales y entre paredes y cimientos para garantizar un comportamiento tubular) conduce a un rendimiento sísmico superior (prácticamente sin daños en un terremoto severo) sin necesidad detalles complejos y con costos de construcción competitivos. ...
Thesis
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El objetivo principal del presente trabajo de investigación consiste en el estudio del comportamiento estructural del sistema constructivo de paneles aligerados con poliestireno expandido, malla electrosoldada espacial y hormigón proyectado in-situ, usualmente llamados “paneles sándwich”. En particular, se buscar identificar y obtener los parámetros que caracterizan su respuesta frente a distintas solicitaciones y proponer una metodología para el cálculo estructural del panel a través de software basados en la teoría de elementos finitos.
... In these studies, specimens were tested in vertical position and vertical and lateral deflections were recorded. Performance of RCSP panels under lateral and seismic loading was also investigated, experimentally, by some of the past researchers [8,9,10,11] and analytical models were developed for designing of the RCSPs. A Column model was developed considering the combined effect of bending and shear [10,11] and was used to estimate the seismic response of real-size (one to four storey) RCSP box type buildings [11]. ...
... Performance of RCSP panels under lateral and seismic loading was also investigated, experimentally, by some of the past researchers [8,9,10,11] and analytical models were developed for designing of the RCSPs. A Column model was developed considering the combined effect of bending and shear [10,11] and was used to estimate the seismic response of real-size (one to four storey) RCSP box type buildings [11]. ...
... Performance of RCSP panels under lateral and seismic loading was also investigated, experimentally, by some of the past researchers [8,9,10,11] and analytical models were developed for designing of the RCSPs. A Column model was developed considering the combined effect of bending and shear [10,11] and was used to estimate the seismic response of real-size (one to four storey) RCSP box type buildings [11]. ...
Article
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The structural behavior of Expanded Polystyrene (EPS) core Reinforced Concrete Sandwich Panels (RCSP) under axial and in-plane shear loading is studied, experimentally. An experimental study is conducted on RCSP consisting of factory made corrugated EPS core, welded wire mesh, and orthogonal shear connectors. Total 14 specimens (six of axial compression and eight of diagonal compression) are constructed and tested. The specimens are tested in displacement control mode with Digital Image Correlation (DIC) to measure displacements and strains. The mode of failure, propagation of cracks, ultimate axial load carrying capacity, in-plane shear strength, and stress–strain curves are presented in this article. The experimentally obtained axial load capacity and shear strength are also compared with those calculated analytically. The axial load capacity obtained analytically is in good agreement with experimental results, but the shear strength obtained from experiment is much higher than that estimated using the design codes for reinforced concrete.
... Precast concrete structure has been widely used because of the distinct advantages of high quality, high industrialization level, fast construction speed, low labor intensity, and green construction [1][2][3][4][5][6][7][8]. Over the last decades, many countries and regions, such as the United States, Japan, China, and Europe, have been increasingly advocating the precast concrete structure system for residential and industrial buildings [3,4]. ...
... Over the last decades, many countries and regions, such as the United States, Japan, China, and Europe, have been increasingly advocating the precast concrete structure system for residential and industrial buildings [3,4]. Especially, the low-rise precast structures, most of which adopt the precast wall panel structure system [2,3,9,10], have a wide application in building construction [2,3]. Meanwhile, previous studies have shown that the structure system adopting precast reinforced concrete shear wall as the main lateral resistance component exhibits a good seismic performance [11][12][13]. ...
... Over the last decades, many countries and regions, such as the United States, Japan, China, and Europe, have been increasingly advocating the precast concrete structure system for residential and industrial buildings [3,4]. Especially, the low-rise precast structures, most of which adopt the precast wall panel structure system [2,3,9,10], have a wide application in building construction [2,3]. Meanwhile, previous studies have shown that the structure system adopting precast reinforced concrete shear wall as the main lateral resistance component exhibits a good seismic performance [11][12][13]. ...
Article
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This paper develops a novel dry connection utilizing high-strength bolts and introduces the corresponding low-rise precast wall panel structure system. To investigate the seismic performance of the structure system with full bolt connections, monotonic loading tests of the connection joint and cyclic lateral loading tests of three full-scaled precast shear walls are both conducted. Based on the test data, axial and shear mechanical models of the connection are given. Meanwhile, experimental results show that the failure mode of the connection is dominated by anchored rebar ductile rupture, and the precast structure system presents a stable energy dissipation capacity and a good seismic ductility. The numerical model of the precast shear wall is then developed and validated by the cyclic loading test. Also a simplified calculation method to predict the lateral strength of the precast shear wall is proposed. According to the calculation results, the distance between the center of the connection and the edge of the shear wall is suggested to be 150 mm, while the wall thickness is recommended to be 120 mm or 150 mm. Finally, a three-story precast wall panel structure is employed to assess the collapse performance of the proposed precast structure system by using the presented numerical model. The results indicate that the proposed structure system with full bolt connections has high stiffness and high seismic resistance against collapse.
... Lightly reinforced walls are usually examined either to evaluate the response of walls that were constructed with substandard details or in special shearwall structures. [7][8][9] In Ref. [10], the recommendations given in Ref. [11] are adopted, using the height and length of the wall for the calculation of the plastic hinge length. In a recent study, 12 various equations for the estimation of plastic hinge length were checked by means of artificial neural networks, and it was found that the form proposed by Eurocode 8 is remarkably accurate. ...
... Moreover, while the majority of previous papers [7][8][9][10][11] developed 2D simplified nonlinear FEM models to reproduce the experimental data, very few works can be found on the 3D nonlinear FEM design, taking also into account the influence of a rigid insulation layer [12,16]. As far as the inplane shear under a constant compression load of RC sandwich panels is concerned, most of the research work accomplished up to date was focused upon the experimental characterization of the seismic behavior after a certain number of horizontal lateral loading cycles, [17][18][19][20][21][22][23][24][25]. Precast and cast in-situ RC sandwich walls were tested through shear tests with/without constant compression. ...
Article
The paper deals with the experimental and numerical characterization of the in-plane axial and shear mechanical behavior of sprayed in-situ reinforced concrete (RC) sandwich panels, used as structural walls. Axial compression tests were carried out on specimens with different slenderness ratios to study their behavior under axial vertical loads. While the diagonal compression test and shear load with constant compression test were respectively performed on squared panels, analyzing their response to in-plane horizontal lateral forces. Ultimate axial and shear loads have been experimentally determined and the most significant load–displacement diagrams have been reported. The obtained results have been compared with other experimental campaigns on RC sandwich panels and with conventional RC walls equations, available in codes of practice and literature. The structural potentialities of RC sandwich panels as load-bearing and shear walls are highlighted. The experimental investigation is corroborated by a 3D nonlinear finite element (FE) numerical analysis, considering the influence of the insulation layer, the efficiency of steel connectors, and the involved material nonlinearities.
... In this paper, the RC beams, columns, and rocking walls are modelled via displacement-based beam-column (dis-pBeamColumn) fibre elements, in which their concrete and steel reinforcement materials use Concrete01 (because the tensile strength is less than the compressive strength, Concrete01 is used to build model) and Steel02 (the elastic tangent of reinforcement is 200 GPa, and strain-hardening ratio is 0.01), respectively. Some approaches have been proposed to model the panels (or walls) such as the multilayer element [32] or rigid beam element [33] with the bottom linked by a nonlinear zero-length element. e cladding panels and floors are simulated by shell elements, and the material adopts an elastic model. ...
Article
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An approach combining U-shaped dampers (USDs) and rocking walls is proposed in this paper to improve the seismic performance of traditional precast reinforced concrete (RC) frames with cladding panels (PRCFCPs): (1) the steel bar and USD connection methods are adopted at the top and bottom of the cladding panels to use the relative deformation between the cladding panels and the main structure and then dissipate the seismic energy and (2) rocking walls are added to the structure to control the structural deformation profiles. The USD numerical model is calibrated using the test data, and a series of nonlinear pushover analyses, dynamic time-history analyses, and incremental dynamic analyses are successively performed to compare the seismic performance and collapse capacity of the PRCFCP, PRCFCP with USDs (PRCFCP-USD), and PRCFCP with USDs and rocking walls (PRCFCP-USD-RW).The results show that the USDs in the PRCFCP-USD-RW undergo more uniform deformation along the structural height and higher energy dissipation efficiency and the PRCFCP-USD-RW exhibits enhanced seismic performance and collapse capacity, which verify the superiority of the proposed combined approach.
... At present, 'wet' methods have been widely used to facilitate constructability of most precast structures, such as connecting vertical reinforcing bars with mechanical couplers or lap splices and then placing cast-in-situ concrete or fresh cementitious grout [15][16][17]. Several innovative PC shear walls were investigated in the past 20 years, such as hollow core precast wall [18], sandwich wall [19,20], and light-weight wall [21]. All these efforts are aimed at improving construction speed as well as maintaining construction quality, while the aforementioned 'wet' methods all require some cast-in-situ work, which reduces the construction efficiency to some extent. ...
Article
Full-text available
A novel Precast Concrete (PC) shear wall system was developed to achieve a dry and convenient assembly method, with the system consisting of bolted connections between precast wall panels. T-connectors were utilized for horizontal connection of the panels, friction-bearing devices and end columns were utilized for vertical connection. A series of pseudo-static reversed cyclic loading tests were conducted on four shear walls, including one conventional cast-in-situ wall and three novel PC shear walls. The test results indicated that the performance of the PC wall containing friction-bearing devices was generally superior in terms of strength, drift capacity, energy dissipation and ductility. It is concluded that the vertical connections delayed stiffness degradation and led to increased lateral drift capacity. Furthermore, study of the vertical connections provided further insight into the elongation of ductile reinforced concrete members.
... In the last decades, researches on precast building's seismic performance have been systematically carried out [6][7][8][9], some of which show that structure adopting precast reinforced concrete shear walls as the main lateral force resistance presents a good seismic performance [8,9]. At present, a variety of precast wall panel structure system have been reported, such as unbonded post-tensioned precast concrete shear walls structure [10][11][12], steel-concrete composite shear wall structure [13], shear wall structure with metal bellows grouting [14], and new types of sandwich and light-weight wall structure [8,[15][16][17][18][19]. The precast concrete shear wall structure has a great potential in the development of residential building industrialization. ...
Article
Double-skin composite walls have been increasingly applied in high-rise buildings. The behavior of connection to the wall under seismic action is essential to the performance of the whole structures. This paper investigated the experimental seismic behavior of four proposed connections to an innovative double-skin composite wall. The wall employs steel trusses as internal connectors. Large-scaled cyclic tests were performed on connections with different configurations. The seismic behavior was evaluated in terms of failure mode, hysteretic response, stiffness degradation, ductility, and energy dissipation ability. The test results found that all specimens exhibited stable and plentiful hysteretic performance without noticeable pinching effect. Reasonable stiffness degradation, good ductility and satisfying energy absorbing capacity were also observed. Strain distributions at key locations were analyzed to evaluate the strain development at beam, stiffener, and wall face. It is concluded that the connection with vertical stiffeners has good seismic behavior. The application of vertical plate or additional cover plate is also acceptable. In addition, the use of through plate should be careful as the welding quality is important to the behavior of connections.
Article
The maximum displacement responses under the seismic motions are usually considered as an indicator for damage evaluation. It is obvious that appropriate selection of drifts corresponding to various damage levels plays an important role in safety and economy of a design project. Despite the extensive use of the box-type structural system in mass construction and housing industry, there is no special design requirement for this structural system. Due to three-dimensional behavior and interaction of intersecting walls and slabs, it is expected that this system presents different seismic performance in comparison to the conventional shear wall buildings. This study evaluates the overall and story failure mechanism as well as global and local damage indices in this structural system. Maximum allowable drift ratios of 0.45%, 0.65%, and 0.8% are suggested for the immediate occupancy, life safety, and collapse prevention levels, respectively. Moreover, a damage index based on the maximum relative inter-story drifts is proposed to assess the failure in the height domain. According to the assessments, the story and global failure occurring due to considerable damages in main load bearing elements reveals high importance of local damage indices in box-type structural system. Based on the results, it is concluded that the proposed maximum values for drifts in different standards and codes are not reliable. Considering the shear-control behavior and depending on the expected performance levels, the proposed local damage indices are considered as accurate control indicators for box-type structural system.
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Recent major earthquakes in the Italian territory have reaffirmed the seismic vulnerability of precast industrial buildings typical of past Italian building practices, highlighting structural deficiencies observed during previous events and primarily related to the transfer of horizontal forces between structural and nonstructural elements. An intrinsic lack of shear and ductility capacity has been observed in simply supported beam-to-joist and beam-to-column connections, primarily constituted by vertical steel dowels or solely relying on shear friction, with or without neoprene pads. These connections were designed neglecting seismic loads and their premature failure was observed during recent seismic events to cause a loss of support of beam elements, owing to the relative movements of elements, and the collapse of part of the buildings, primarily the roof. The seismic displacement demand of the industrial buildings under consideration is larger than traditional RC frame structures owing to their higher flexibility, according to both higher interstory height and to a cantilevered static scheme. Furthermore, this high flexibility may also result in displacement incompatibility between structural and nonstructural elements, such as precast cladding panels, causing their connection failure. On the basis of detailed field observations on a relevant number of buildings, collected just after the earthquakes, seven representative industrial facilities are examined to outline the primary vulnerabilities of one-story precast concrete structures not designed and detailed for seismic loads.
Chapter
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Nonlinear simulations for structures under disasters have been widely focused in recent years. However, precise modeling for the nonlinear behavior of reinforced concrete (RC) shear walls, which are the major lateral-force-resistant structural member in high-rise buildings, still has not been successfully solved. In this paper, based on the principles of composite material mechanics, a multi-layer shell element model is proposed to simulate the coupled in-plane/out-plane bending or the coupled bending/shear nonlinear behaviors of RC shear wall. The multi-layer shell element is made up of many layers with different thickness. And different material models (concrete or steel) are assigned to various layers so that the structural performance of the shear wall can be directly connected with the material constitutive law. And besides the traditional elasto-plastic-fracture constitutive model for concrete, which is efficient but does not give satisfying performance for concrete under complicated stress condition, a novel concrete constitutive model, referred as micro-plane model, which is originally proposed by Bazant et al., is developed to provide a better simulation for concrete in shear wall under complicated stress conditions and stress histories. Three 10-story buildings under static push-over load and dynamic seismic load, with various shear wall arrangements, were analyzed with the shear wall model proposed in this study. The simulation results show that the multi-layer shell elements can correctly simulate the coupled in-plane/out-plane bending failure for tall walls and the coupled in-plane bending-shear failure for short walls. And with micro-plane concrete constitutive law, the cycle behavior and the damage accumulation of shear wall can be precisely modeled, which is very important for the performance-based design of structures under disaster loads.
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