Papers by Keyword: Pseudo-Static Test

Abstract: According to current engineering practice, Confined Masonry (CM) buildings are weak in earthquake resistance and difficult in post-quake restoration. A new form of structure, i.e. Hybrid Masonry – Reinforced Concrete Structure (HMRCS), is investigated. By slightly increasing the sizes and reinforcement ratios of the RC members, i.e. beams and columns, which normally only act as confinement in a CM structure, now play an essential role in resisting the gravity load in HMRCS, while the masonry wall mainly resists the lateral earthquake load. To investigate the seismic-resistant behavior, pseudo-static tests on two full-scale HMRCS specimens were conducted, and the measured hysteretic curves were analyzed. Finite Element (FE) simulation was performed to verify the working mechanism and seismic response of the HMRCS specimens. The lateral displacement ductility factor obtained from the experimental results can fully satisfy the seismic requirement of structures. Therefore, HMRCS is reliable if its RC frame members and masonry walls are designed properly. Furthermore, the feasibility of using FE software to study the proposed HMRCS has been validated by comparing the experimental and simulation results.

Abstract: A two-story masonry housing model was made in this paper. According to Intensity 7, adjusted Northridge record was selected to be the ground motion input in the pseudo-dynamic test. Pseudo-dynamic test and pseudo-static test were carried out to investigate the seismic behavior of the model structure. The time-history curves of the acceleration, velocity, displacement and restoring force of the structural response were obtained besides the time-history curves of the measuring points of the structure. Also the steel strain of the tie-columns and the hysteresis loops of the structure were obtained. The result shows multi-story confined masonry structures possess superior seismic performance if coordinated with the provision specified in the current compulsory design code and it can continue to use after appropriate dressing under the rarely earthquake.

Abstract: in this paper, four single-layer masonry wall models in1/8 scale were made by a kind of special bricks on the basis of an ancient masonry pagoda structure. The models are divided into two groups by whether there is a masonry floor in a model or not. Pseudo-static test is introduced to study the seismic performance of four models with a special load control process which is suited to masonry structure. According to the test results, the horizontal bearing capacity and ductility of each masonry walls reinforced with steel straps under horizontal low cyclic loading has been sorted out. Four nonlinear restoring force models are inferred from the experimental results and phenomena under various operating conditions. And the shear capacity calculation formula of reinforced masonry wall models is fit out. The theory and experimental study show that seismic performance of the masonry pagodas strengthened with steel straps has been improved significantly.

Abstract: In order to acquire the seismic performance of three different types of nodes between the concrete frame and the light steel adding storey, the pseudo-static tests were carried out to analyse contrastively these specimens’ failure modes, stiffness degradation, hysteretic curves and energy dissipation. The test results showed that : Three nodes’ destruction were due to the plastic hinges emerging at the end of beam; both encased steel and carbon fiber strengthening method can improve the seismic behavior, and in terms of the ultimate bearing capacity, energy consumption ability，the encased steel strengthening one can improved more significantly, and the encased steel one can effectively slow down the speed of stiffness degradation.

Abstract: Based on the pseudo-static tests among three different types of joints (traditional planted-bar joint, the CFRP strengthening joint and the transformed-connection joint) between concrete frame and adding light steel storey, the research was carried out to contrast the seismic performance of these joints. The results showed that: three joints’ destruction was due to the plastic hinge and the maximum crack appearing at the end of beams, the seismic performance of the two new types of joints were better than the traditional planted-bar joint; Among the three joints, the hysteresis curve envelope area of CFRP strengthening joint was the biggest and the energy consumption was the most powerful; The stiffness of transformed-connection joint was improved significant, and its manufacture technology of joint was simple and convenient.

Abstract: The seismic behavior of concrete-filled circular steel bridge piers was studied by testing four large scale models which were subjected to a constant axial load in addition to a cyclic lateral load. It was found that concrete-filled circular steel bridge piers had high ductility and energy dissipation capacity. Based on the hysteretic force-displacement, the hysteretic behavior of strength reduction was analyzed. Based on the axial strain and the circumferential strain, the plastic area and the strain feature of steel tube were analyzed. According to two different constitutive models of concrete-filled steel tube, the skeleton curve of moment-curvature and force-displacement were calculated and compared with testing data.

Abstract: This paper mostly studied on the pile stress in the loess foundation when the pile and the soil are interacting by pseudo-static test of piers and piles in the remolded loess foundation indoor. We get the stress-depth curve of pile body. We get its finite element model by ANASYS and analyze the change of pile body stress.

Abstract: To enhance the earthquake resistance capacity of long-span continues bridge, theory and design of a new seismic isolating system are proposed based on the utilization of improved carbon structural steel material. Pseudo-static test result of the damping tenon, one essential energy dissipation component, proved the system’s excellent characteristic of consuming earthquake energy. Comparative experiments of three models reflect the working stability of the damping tenon confronted with different stimulation. Finite Element simulation further validates accuracy of the experiment and helps analyzing the material’s elastic and plastic developing status due to different load steps. Finally, this new seismic isolating system is recommended to long-span continues girder bridge designed on the basis of high level earthquake resistant standard.

Abstract: The pseudo-static tests of two “T” cross-section samples were carried out to study the shear performance of reinforced block short-leg masonry shear wall (RBSMSW), under constant vertical loading. Crack propagation and failure pattern, bearing capacity, load-deformation relationship and energy-dissipation capability were studied, which it identified the parameter values in this experiment and validated the corresponding formulas that can be used in practical design. Also, experimental analysis verifies that both failure mode and ductility of RBSMSW are similar to those of the reinforced concrete short-leg shear wall (RCSSW).

Abstract: Pseudo dynamic test and pseudo static test were carried out on 1/2 scale model of light composite structure. By experimental research, hysteretic curves of base shear force and top displacement of the model structure were got, which come from various sections of pseudo dynamic test and pseudo static test, and through hysteretic curves of base shear force and top displacement of the model structure, skeleton curve of base shear force and top displacement of the model structure can be got. Outside line of all skeleton curves was skeleton curve of the light composite structure model. By analyzing and simplifying of the skeleton curve, finally restoring force model of the model structure was obtained, so reasonable dynamic analysis method of seismic design of the model structure can be offered. Research shows that as peak acceleration of inputting seismic wave continuously grows, especially when the peak acceleration reaching 800 gal, after the model structure reached plastic stage and in the stage of pseudo static test, the hysteretic curves become fuller and fuller, which shows that, with continuous emerging and propagation of crack, the structural rigidity losses gradually, and its energy dissipation capacity increases gradually. So earthquake fortification level of not collapse when hit by rarely occurred earthquake will achieve.