Frame-shear Wall Structure Research Articles

DYNAMIC MODEL AND SEISMIC RESPONSE ANALYSIS OF FRICTION SURFACE ISOLATION STRUCTURES

In view of the large displacement and residual deformation of friction-slip isolation systems under strong earthquakes, we propose a friction surface isolation structural system, in which the superstructure moves reciprocally around the curvature center of the isolation layer under earthquakes and gravity. A simplified single-point double-mount editing mechanical model of the friction surface structure is established. The expression of the bearing axial force and its parameter correlation are obtained based on the equation of motion. The shake table test of a reinforced concrete frame shear wall structure model was completed. The experimental results show that the acceleration response of the friction surface isolation structure is slightly increased compared with that of plane friction slip structures, but it has better effect in controlling the displacement of the barrier layer and bearing stress of the isolation layer. The numerical simulation of the shake table test was carried out. The correctness was verified by comparison of the test results. The effect of the curvature radius and the coefficient of friction of the isolation layer on the structural response was analyzed by numerical simulation.

Seismic performance of RC frame-shear wall structures with vertical setback

The reinforced concrete (RC) frame-shear wall structure is a typical structural system for modern high-rise buildings. This paper investigates the influence of vertical setback on its seismic performance through elasto-plastic time history analysis on three groups of models under different levels of earthquakes excitation. The studied variables include setback percentage, local lateral stiffness ratio and setback position, which cause vertical irregularity to the structure. It is confirmed that existence of setback increases the inter-storey drift ratio at the setback position due to the sudden change of lateral stiffness thereby. Compared to the structure without setback but having the similar local lateral stiffness, the maximum inter-storey drift ratio is smaller due to the reduced mass associated with the existence of setback. To quantify vertical irregularity, limitation on the local lateral stiffness ratio can be relaxed to some extent for structures with setback. Considering the resulted variation of inter-storey drift ratio, setback percentage and lateral stiffness ratio are equally important. Along the height, setback at the middle height gives larger inter-storey drift ratio and seismic force.

The applied research on Tuned Liquid Damper in practical engineering with three-dimensional numerical simulation

The practical application of high-position fire-fighting water tanks on the top-level of office buildings in State Grid Corporation of China is studied in this article. Fluid-solid-coupling mathematic models were established based on ABAQUS finite element analysis software to compare the calculational results in two-dimensional situations and three-dimensional ones. Meanwhile, a 22-storey frame-shear wall structure named Innovation Mansion was selected to discuss the vibration reduction effect of TLD. The results indicate that the fliud-solid-coupling analytical method could reflect the nonliear character of TLD-structure systerm precisely, and the aseismic ratios were 2%~5% variation between two-dimensional models and three-dimensional ones. The TLD has positive effects on controlling the structural seismic responses and the aseismic ratios could reach 10% around, besides, the TLD damping force not only offset the increased base-shear arose from its own weight, but also reduced the total base-shear.

Seismic Performance of Frame–Shearwall Structure with Long-Span and High-Level Steel Transfer Trusses

Based on a shaking table experiment a 1:25 scaled frame–shearwall structure model with large-span steel transfer trusses and finite-element analysis, the dynamic characteristics, seismic responses in the elastic and elastic–plastic phases, and destructive forms of the structure were studied. It was observed that cracks developed as the earthquake wave acceleration increased, but no severe cracking developed in the structure during the experiment. In the seismic responses caused by the artificial accelerogram, the site accelerogram and the El Centro accelerogram, that caused by the artificial accelerogram was the most intense. The interstory drift between transfer stories is large, which means that the transfer stories might be weak. However, the seismic performance of the steel truss transfer stories was good and the structural system was able to meet the seismic requirements regulated by the Chinese Design Code.

Experiment investigation and seismic performance evaluation of hybrid isolation bearing with uncoupled compression and shear mechanism

SummaryLead rubber bearings (LRBs) are widely used in the seismic isolated structures. However, the lateral and vertical stiffness of rubber bearing would degrade under high pressure and larger shear strain, which has influence on the structural safety under great earthquakes. This paper proposes a novel hybrid isolation bearing (HIB) with uncoupled compression and shear mechanism. The HIB consists of sliding bearing and rubber springs, carrying superstructural weight and providing lateral stiffness, respectively. The configuration and mechanical model of the HIB are introduced, and an experiment investigation on two sizes of HIB was completed. Through the model test, the deformation mechanism and the mechanical model were verified. A numerical simulation of a frame–shear wall structure was performed, and the variation of structural responses is illustrated. Compared with conventional LRB isolated structure, the HIB isolated structural has similar response variations under earthquakes from frequent to rare levels. Under extremely rare earthquakes, the HIB has more stable mechanical behavior.

Shaking table test and investigation of rocking effect in a high-rise isolated structure

Laminated rubber bearings have a large compression stiffness and small tension stiffness and isolation layers show rocking deformation under bending moments. The application of isolation technology is limited in high-rise structures due to the unequal compression and tension stiffnesses. The rocking effect of a high-rise isolated structure was investigated in this work. To do this, a dynamic model of a high-rise isolated structure considering non-linear tension behaviour of the isolator and the stiffness centre offset was established. The limit criterion of the rocking angle and the corresponding input peak ground acceleration of the tension limit, damage limit and collapse limit were determined. A shaking table test of the isolated model was conducted and the aspect ratio was found to have a great influence on the structural rocking response. The response of the large aspect ratio (LAR) model was larger than that of a model with a small aspect ratio. The bearings in the LAR model were more likely to be tensioned. The test results and numerical simulations were close, confirming the accuracy of the proposed dynamic model and the limit criteria. Subsequently, dynamic analysis of frame–shear wall structures was conducted and the influence of aspect ratio and earthquake level was investigated. The proposed theories can be applied for direct predictions of rocking response and the performance state of isolators.

The comparison analysis of earthquake resistant behavior between frame structure and frame shear wall structure

According to the investigation of earthquake damages in China and abroad, the earthquake resistant behavior of frame shear wall structure is better than that of frame structure. Compared to the reinforced concrete fame shear wall structure, the fame structure is easier to be damaged under the action of earthquakes. In this paper, the five-storey frame structure model is taken as the research object, and a certain number of shear walls are reasonably arranged to form a frame shear wall structure to compare and analyze the earthquake resistant behavior of the two structures. The analysis results show that the frame shear wall structure can achieve good earthquake resistant behavior compared with the frame structure.

Analysis of Construction Technology of Frame Shear Wall Structure

Analysis of Construction Technology of Frame Shear Wall Structure

Structural system selection and design of Zhangzhou Opera House Fujian Province

Zhangzhou Opera House adopts the complex structure system of petal shape. According to the building shape and architectural layout, the structure combines the steel truss for large-span space and the frame-shear wall structure surrounding. This article introduced its structural system, multi-line defense line arrangement and anti-seismic performance objectives, and summarized the structural characteristics of the overall structure, especially focusing on key issues such as setting the ring floor beam to resist the extroversive forces, anti-seismic performance of key components and the design of the junction between the steel truss and concrete structure. The results show that the structure has strong adaptability to the building shape with suitable seismic performance, and fulfilling both the requirements of seismic performance design and the structural safety.

Damage Quantification of Frame-Shear Wall Structure with Metal Rubber Dampers under Seismic Load

The seismic load can bring serious damages to the coupling beams and frame beams in the frame-shear wall structure. Such damages can hardly be repaired, causing functional loss to the structure. One of the best ways to consume seismic energy input, rationalize the damage mode of structure, and prevent serious damages to the main components is to install metal rubber (MR) dampers materials in the frame-shear wall structure. Based on Park and Ang’s damage model, this paper presents pertinent formulas of damage indexes, and uses them to quantify the failure mode. Then, the correspondence was established between damage level of the target structure, reasonable damage mode, and damage index. Finally, two ABAQUS models of an 18-floor frame-shear wall structure were constructed: an uncontrolled structure (traditional frame-shear wall structure) and a controlled structure (frame-shear wall structure with MR dampers). Through comparative analysis, the characteristic parameters of the damper were determined for the reasonable damage mode, and the failure mechanism of the target structure was identified accurately under seismic load.

Racking performance of poplar laminated veneer lumber frames and frame-shear hybrid walls

This study examined the racking performance of poplar laminated veneer lumber (LVL) frames using bolted steel filling plates to connect beam-column joints, poplar LVL frames using the embedment bars to connect beam-column joints, and frame-shear hybrid walls made of poplar LVL studs and oriented strand board (OSB) sheathing panels. A new design load spreader beam was used on the side of the top of a specimen to apply monotonic and cyclic loadings. It was found that the lateral force resistance, stiffness, and ultimate loads of poplar LVL pure frames with bolted steel filling plate connections and closed rod connections were much lower than those of the poplar LVL frame-shear wall hybrid structure. The highest initial stiffness of the poplar LVL hybrid frame-shear wall was 1.77 kN/mm, which was 24% and 22% lower than that of the conventional shear wall made with spruce-pine-fir studs and OSB or plywood sheathing panels, respectively. The poplar LVL frame-shear wall hybrid structure showed lower degradation in stiffness than the conventional shear wall. The hybrid frame-shear wall structures made of poplar LVL could meet the requirements of Chinese standard; however, diagonal braces were required in use of poplar LVL pure frames.

Seismic Response of Reinforced Concrete Frame-Shear Wall Structure with Metal Rubber-Based Damper in Coupling Beam

In reinforced concrete (RC) frame-shear wall structure, the coupling beam needs to yield before the wall limbs are damaged, in order to dissipate the energy of the external load. However, the coupling beam has a limited energy dissipation capacity. Once severely damaged, the coupling beam is difficult to be repaired, which hinders the structural recovery after an earthquake. Considering excellence of metal rubber (MR) in hysteresis energy dissipation and deformation self-reset, this paper changes the energy dissipation mode of the coupling beam by adding an MR damper to the beam. Firstly, the stress-strain curve of MR was obtained through mechanical experiments, and used to construct the constitutive model of the material. Then, the parameters of the damper were designed based on the constitutive model. Next, the MR dampers were installed on the coupling beams of a 12-layer RC frame-shear wall structure. The authors analyzed the time histories of the elastoplastic dynamics of the structure under seismic actions, and calculated the seismic responses like interlayer displacement, absolute acceleration, and base shear force. These parameters were compared with those of the structure without the damper, and the output-deformation envelope curve of the damper on each layer were obtained. In this way, the authors studied how the parameters of the MR damper affect the seismic response of RC frame-shear wall structure. The results show that adding the MR damper to coupling beam can effectively weaken the seismic response of the RC frame-shear wall structure.

A Theoretical Study of Estimating the Elastic Responses of Framed Self-Centering Wall Structures under Lateral Loading

The framed self-centering wall (FSCW) structure is a newly-emerged special type of seismic-resistant system. However, the related studies rarely concern the theoretical investigation of the FSCW structures subjected to lateral loading, which is of great importance for seismic design of the FSCW structures. In view of this, the analytical model of the FSCW structures is firstly developed, then the fundamental equations that govern the elastic responses of FSCW structures under lateral loads are formulated and the corresponding analytical solutions are derived. Meanwhile, the developed analytical model is validated by the finite element method, which shows that the developed model has a good reliability in predicting the elastic responses of FSCW structures sustaining lateral loading. Utilizing the proposed method, the effects of the post-tensioned (PT) tendon and dampers on the behaviors of the FSCW structure under lateral loading are investigated. Moreover, a comparative study of mechanical performance between the FSCW structure and conventional structures under lateral loading is conducted. The results show that, in terms of the lateral displacement and shear force responses of the frame, the mechanical performance of the FSCW structure subjected to lateral loading generally falls in between those of the conventional frame-shear wall structure and the moment-resisting frame structure.

Analysis and Application of Shock Absorption Measures for High-rise Inpatient Building of a Hospital in High Intensity Fortification Area

A proposed 22-storey hospital building is located in an area with 8-degree seismic fortification and is a reinforced concrete frame-shear wall structure. Through the establishment of structural model, calculation and comparative analysis are carried out by using ETBAS and PERFORM-3D software. The viscous damping wall is used for energy dissipation and damping, and the optimal damping scheme is determined by multi round time history analysis and optimal adjustment of the number and location of dampers.

Collapse Patterns and Their Discrimination of Reinforced Concrete Shear Wall Under Combined Stresses of Compression and Shear due to Strong Earthquake

The collapse patterns of reinforced concrete (RC) shear walls under seismic load are proposed. The crack distribution and propagation of shear walls are specifically based on the failure criterions of Mohr-Coulomb with tension cutoff. Three zones and five different corresponding failure modes of RC shear walls are determined according to the transfer path of shear stress in shear wall. These failure modes of shear walls under seismic load are verified by many experimental results and can be utilized in collapsing analysis for frame-shear wall structure.

Analysis on seismic behavior of different structural systems of small high-rise buildings

In order to study the seismic performance of small high-rise building under different structural systems, an ordinary residential tower building of 11 floors in 7 degree area was designed as a frame structure, frame-shear wall structure and shear wall structure respectively. Elastic calculation of all structures was conducted based on FE model built by the software of YJK and elasto-plastic time-history analyses were conducted by the software of PERFORM-3D. The numerical results confirm that all of the three kinds of structure system can meet the requirement that the beam yield firstly, but vertical force component dose not yield in rare earthquake. On the frame-shear wall structure, the inter-story drift angle can be controlled better. The proportion of plastic energy dissipation of the frame structure is the highest and of the shear wall structure is the least among the three structures. All kinds of structure systems show good seismic behavior.

Study on Static Elastoplastic Analysis of a High-Rise Frame-Shear Wall Structure

Static elastoplastic analysis is a widely used method to evaluate the seismic performance of structures. The project example in this paper is the high-rise frame-shear wall structure of the second phase (Yongsheng homeland) of the Baisha resettlement area in Zhengdong New Area. The three-dimensional integral model is used to calculate the force of the building under earthquake using the static elasto-plastic analysis method. Analysis was conducted to obtain the stress conditions of high-rise buildings against plastic deformation, and the sequence of the plastic hinges, and the unfavorable floors of the high-rise structure were identified, which provided guidance for the design of such structures.

Energy-based collapse assessment of concrete structures subjected to random damage evolutions

The assessment of structural capacity against collapse is conducive to the optimal design of new structures as well as checking the safety of existing structures. However, the evaluation cannot be typically carried out by means of destructive tests on prototype or reduced scale structures. In this regard, the numerical models that adequately represent the prototype structures can be alternatively used. Specifically, both the nonlinearities and randomness as well as their coupling effect of materials need to be represented in a unified manner in structural analysis. The present paper aims at providing an effective approach to incorporate the stochastic nature of damage constitutive relationships in collapse analysis and assessment of concrete structures subjected to earthquake ground motions. Within the framework of stochastic damage mechanics, the spatial variability of concrete is represented by a two-scale stationary random fields. The concept of covariance constraint is introduced to bridge the two-scale random fields such that the scale-of-fluctuation of the random material property is satisfied at both scales. Random damage evolution induced structural collapse analysis is achieved via the nonlinear stochastic finite element method. To address the randomness propagation across scales, the probability density evolution method is employed. By exerting the absorbing boundary condition associated with an energy-based collapse criterion on the generalized probability density evolution equation, the anti-collapse reliability of concrete structures can be evaluated with fair accuracy and efficiency. Numerical investigation regarding an actual high-rise reinforced concrete frame-shear wall structure indicates that the random damage evolution of concrete dramatically affects the structural nonlinear behaviors and even leads to entirely different collapse modes. The proposed method provides a systematic treatment of both uncertainties and nonlinearities in collapse assessment of complex concrete structures.

Research on Optimal Design of Foundation Pit Anchor Support based on Improved Particle Swarm Optimization

The engineering technology of deep foundation pit support is complex and comprehensive, and it is necessary to consider the relationship between safety and engineering cost, and the optimal design of foundation pit support is especially important. Anchor support is a common support way for deep foundation pit support, in allusion to the shortcomings of particle swarm optimization; this paper adopts genetic algorithm, step length acceleration method and improved particle swarm optimization to carry out optimal design for foundation pit anchor support. The optimization results show that the combination with genetic algorithm improves the diversity of particle populations, the particle swarm optimization combined with the step length acceleration method has faster convergence performance, and the mathematical model of anchor supporting structure design is established. Through the case study of the foundation pit support of the super-high-rise building with frame shear wall structure, it was found that the engineering cost of the improved anchor support scheme after the improved particle swarm optimization is lower. The research in this paper provides a mathematical model for foundation anchor support.

Effect of Connection Deficiency on Seismic Performance of Precast Concrete Shear Wall-Frame Structures

The quality of precast concrete (PC) component connections is one of the main factors that affect the seismic reliability of PC structures. China is developing PC structures in high seismic regions, and it is important to assess the effect of connection deficiency on seismic performance of PC structures. This paper presents a comprehensive method to assess the seismic reliability of PC shear wall-frame structure whose wall panels are assembled through grouted sleeve connections which are susceptible to insufficient grouting. Considering the uncertainties associated with the number, locations and loading behavior of defected sleeve connections, the probabilistic behavior of PC shear wall with defected connections is estimated through point estimate method using simulation results of the experiment-validated finite element model. Then, a simple shear wall-frame building, designed for the seismic intensity of 8 according to China’s seismic design code, is modeled on platform of OpenSees. Static pushover analyses and seismic fragility analyses are performed on the structure with different degrees of connection deficiency, to investigate the effect of deficiency occurrence rate on seismic performance. The seismic performance is significantly affected by connection deficiencies; it no longer meets the requirement of seismic design as the deficiency occurrence rate exceeds 25%, so the occurrence rate of defected connections should be controlled carefully in construction site.