Experimental Research on Seismic Response of Heat-Insulating Perforated Brick Full-Scale Walls with Openings

2013 ◽  
Vol 353-356 ◽  
pp. 1896-1900
Author(s):  
Chuan Qing Liu ◽  
Ming Hai Li ◽  
Guang Chun Zhou ◽  
Zuo Yun Mei
Keyword(s):  
Bearing Capacity ◽  
Seismic Response ◽  
Axial Force ◽  
Masonry Wall ◽  
Ultimate Bearing Capacity ◽  
Full Scale ◽  
Window Opening ◽  
New Type ◽  
The One ◽  
Ultimate Displacement

Heat-insulating perforated brick is a new type energy-saving masonry material. In order to investigate seismic response of masonry wall with this new-type brick, a set of quasi-static full-scale cyclic tests are performed. The test results show that this brick owns a good cooperative work system between bearing layer and insulation layer, and vertical axial force is an obvious factor which affects seismic response of heat-insulating perforated brick walls. With the increase of vertical axial force, ultimate bearing capacity increases, however, ultimate displacement can be decreased. In the case of the same axial force, ultimate bearing capacity of the specimen wall with door opening is less than the one with window opening, and the ultimate displacement also is less than the one with window opening.

scholarly journals Experimental Analysis of Seismic Performance of Masonry Shear Wall Reinforced with PP-Band Mesh and Plastering Mortar under In-Plane Cyclic Loading

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Qiang Zhou ◽  
Lingyu Yang ◽  
Wenyang Zhao
Keyword(s):  
Energy Dissipation ◽  
Cyclic Loading ◽  
Bearing Capacity ◽  
Low Cost ◽  
Low Frequency ◽  
Masonry Wall ◽  
Ultimate Bearing Capacity ◽  
Masonry Walls ◽  
Seismic Capacity ◽  
Energy Dissipation Capacity

Masonry structures are widely used in developing countries due to their low cost and simple construction, especially in remote areas, where there are a large number of houses without seismic measures. These buildings are prone to collapse and cause a lot of casualties, even under the action of small earthquakes. For the reinforcement of this structure, a cheap, effective, and easy-to-construct reinforcement method is urgently needed. Therefore, this article studies the reinforcement method of polypropylene bands (PP-bands). We have carried out low-frequency cyclic loading tests for two PP-band reinforced masonry walls and two compared masonry walls. We mainly studied the influence of PP-band and different compressive strengths of plastering mortar on the masonry wall’s seismic capacity. The seismic indicators mainly studied in this article include ultimate bearing capacity, energy dissipation capacity, stiffness degradation, and hysteresis characteristics. The experimental results show that the PP-band can greatly enhance the seismic capacity of the masonry wall. The ultimate bearing capacity, energy dissipation capacity, and displacement ductility of the PP-band reinforced wall are increased by 38%–48%, 22%–47%, and 138%–226%.

Analysis of Bearing Capacity of New-Type Formwork Support Frame

2013 ◽  
Vol 341-342 ◽  
pp. 1449-1452
Author(s):  
Qing Dun Zeng ◽  
Fang Liu
Keyword(s):  
Bearing Capacity ◽  
Structural Stability ◽  
Failure Process ◽  
Ultimate Bearing Capacity ◽  
Load Test ◽  
Solid Model ◽  
Finite Element Software ◽  
Support Frame ◽  
New Type ◽  
Security And Reliability

Various new type scaffolds have been introduced and developed in China. They are novel in structure and economic in material, but their security and reliability can not be ignored. This paper introduced a new chained formwork support frame with nine upright tubes and many cross-braced connections. Firstly, the load test of the support frame was performed in order to observe the failure process and to determine the ultimate bearing capacity. Then, the strength and stability of both single upright tube and a cross-braced rod were checked according to the existing specifications on scaffolds. Finally, a finite element software ANSYS was used to establish a solid model for the support frame. The structural stability was analyzed and the ultimate bearing capacity was calculated. The comparison between the computational and experiment results was carried out. The results show that the ultimate bearing capacity of the new chained formwork support frame is controlled by the structural stability.

Experimental Investigation on Anchorage Mechanisms of Self-Locked Anchor under Combined Tension and Shear

2010 ◽  
Vol 163-167 ◽  
pp. 3600-3603
Author(s):  
Ying Li ◽  
Dong Zi Pan ◽  
Lian Zhang
Keyword(s):  
Experimental Investigation ◽  
Bearing Capacity ◽  
Fracture Pattern ◽  
Ultimate Bearing Capacity ◽  
Design Codes ◽  
Design Recommendations ◽  
Experimental Parameters ◽  
Current Design ◽  
New Construction ◽  
New Type

Self-locked anchor is a new type of underreamed anchor, and which is more and more frequently used in both new construction and structural retrofitting or strengthening projects. Nevertheless, current design codes do not contain suitable design recommendations for these anchors. This study investigates the anchorage mechanisms of self-locked anchor under combined tension and shear loadings. The experimental parameters mainly include anchor diameters (Φ16 and Φ20) and loading angles (0°, 30°, 45°, and 60°). The present results indicate the characters of axial and transverse deformations, the ultimate bearing capacity, the fracture pattern of anchor, and the breakout model of concrete.

scholarly journals Effect of Sand Relative Density inside the Geotextile Pillow on the Bearing Capacity of Pad Foundation

2015 ◽  
Vol 773-774 ◽  
pp. 1428-1432 ◽  
Author(s):  
Mia Wimala ◽  
Herianto Wibowo
Keyword(s):  
Bearing Capacity ◽  
Relative Density ◽  
Factor Of Safety ◽  
Laboratory Experiments ◽  
Ultimate Bearing Capacity ◽  
Performance Criteria ◽  
Sand Surface ◽  
Foundation Model ◽  
The One ◽  
Underlying Soil

A foundation is used to support a building or structure and transmits loads directly to the underlying soil or rock. It must provide an adequate factor of safety against failure of the supporting strata, as well as failure of any excessive settlement which can interfere the function of the structure. Ultimate bearing capacity of a specific foundation is one parameter commonly used to describe the performance criteria of both the soil and the structure above. It can be improved by the inclusion of reinforcements in the ground such as geotextiles. In practice, geotextiles are normally placed directly on the soil in the form of sheet and then covered with aggregates. This research was conducted specifically to investigate the effect of different sand relative densities inside the geotextile pillow, an alternative of geotextile installations in practices, on the bearing capacity of pad foundation by laboratory experiments. A-10 cm x 10 cm pad foundation model was developed in a 1 m3 box filled with sand to actualize this experiment. Geotextile sheet was formed into a pillow, filled with sand with different relative densities and placed at a predetermined depth from the sand surface. As a result, the bearing capacity of the pad foundation model was proved to increase by 50% using a sheet of geotextile compared to the one without any geotextile. Moreover, to the same condition, the use of a geotextile pillow with different sand relative densities inside the pillow, i.e. 30%, 50% and 70% remarkably improved the bearing capacity of the pad foundation model from 150% to 525%. Among the experiment results using a geotextile pillow, the 66.67% addition of sand relative density increased the bearing capacity of a pad foundation model by 100% and 150% with 133.33% of sand relative density. It showed that the increase of the sand relative density inside the geotextile pillow was directly proportional to the increase of the bearing capacity of the pad foundation model.

scholarly journals Development of a New Inflatable Controlled Anchor System and Experimental Study of pull-out Capacity

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Xuexiang Yang ◽  
Shanpo Jia ◽  
Caoxuan Wen ◽  
Yuanjie Liu
Keyword(s):  
Bearing Capacity ◽  
Field Tests ◽  
Ultimate Bearing Capacity ◽  
Inflation Pressure ◽  
Working Mechanism ◽  
Anchor System ◽  
System A ◽  
Pull Out ◽  
New Type ◽  
Soil Interface

Considering the deficiency of traditional anchors, we propose a new type of inflatable controlled anchor system in this paper. The working mechanism and its structural composition of newly designed inflatable controlled device are discussed in detail. To investigate the performance and pull-out capacity of this new anchor system, a series of field tests were carried out under different inflation pressure conditions. By comparing these test results with those of traditional grouting anchors, a full-process constitutive model of anchor-soil interface is proposed to depict the pull-out characteristics of the inflatable controlled anchor. The results show that the ultimate bearing capacity of the inflatable controlled anchor is greater than that of the traditional grouting anchor when the inflation pressure is greater than 0.2 MPa and the ultimate bearing capacity of this new anchor improves obviously with the increase of inflation pressure. When the inflation pressure reaches 0.4 MPa, the ultimate bearing capacity of the inflatable controlled anchor is 2.08 times that of the traditional grouting anchor. Through comparison with the experimental curves, the results of model calculation indicate that the proposed anchor-soil interface constitutive equation can describe the pull-out characteristics of the inflatable controlled anchor. The designed controlled anchor has the advantages of no grouting, recyclability, rapid formation of anchoring force, and adjustable anchoring force.

Experimental Verification on Bearing Capacity of Concrete-Filled Steel Tube Short Columns Based on Unified Theory

2010 ◽  
Vol 163-167 ◽  
pp. 1999-2004 ◽  
Author(s):  
Jing Ji ◽  
Wen Fu Zhang ◽  
Hai Yan Sui
Keyword(s):  
Mechanical Properties ◽  
Bearing Capacity ◽  
Axial Force ◽  
Calculation Method ◽  
Steel Tube ◽  
Ultimate Bearing Capacity ◽  
Unified Theory ◽  
Concrete Filled Steel Tube ◽  
Short Columns ◽  
Load Displacement

To verify the rationality of calculation method on unified theory of concrete - filled steel tube short columns under axial force, Experimental Study on mechanical properties of the 12 concrete -filled steel tube short columns with 7 different sections under axial force is preformed. Failure process and Failure mode of them are observed, load-displacement curves are obtained, and the influence for confinement coefficient ξ to the mechanical properties of short columns under axial load is analyzed. Based on load-displacement curves, ultimate bearing capacities of them are given. By comparison for ultimate bearing capacity obtained by testing and the bearing capacity according to unified theory, the results show both are in good agreement. Calculation method on unified theory of concrete - filled steel tube is fit for calculating ultimate bearing capacity of short columns under axial force with different sections, and the results are safe and reliable.

Concept and Behavior of a Steel Ring Restrainer with Variable Stiffness and Buffer Capacity

2020 ◽  
Vol 14 (04) ◽  
pp. 2050020 ◽  
Author(s):  
Jubo Sun ◽  
Zhanfei Wang ◽  
Diwei Xue ◽  
Hanbin Ge
Keyword(s):  
Bearing Capacity ◽  
Buffer Capacity ◽  
Variable Stiffness ◽  
Ultimate Bearing Capacity ◽  
Design Parameters ◽  
Initial Stiffness ◽  
Strong Earthquakes ◽  
And Behavior ◽  
The Impact ◽  
Ultimate Displacement

In this paper, a novel restrainer called steel ring restrainer (SRR) is proposed to prevent the unseating of bridges. The restrainer is comprised of a steel ring, an upper guiding pulley, a downward guiding pulley, and two connections. The SRR can provide different stiffnesses under different seismic excitations. The SRR is not activated under daily load but provides smaller stiffness in small and medium earthquakes and even larger stiffness in strong earthquakes. The stiffness changes smoothly from small and medium earthquakes to strong earthquakes. This mechanism called buffer capacity reduces the impact on the connection between the SRR and structure. In order to study the effect of each design parameter on the mechanical properties of the SRR, 54 finite element (FE) models in four groups were established and analyzed. The results show that the diameter of the cross-section of the steel ring has an important influence on the initial stiffness, secondary stiffness, buffering capacity, and ultimate bearing capacity of the SRR, the radius of the curved part of the steel ring significantly affected the initial stiffness and ultimate displacement, the nonworking length of the SRR was decided by the length of the straight part of the steel ring, and the diameter of the guide pulley governed the ultimate bearing capacity and ultimate displacement. Additionally, the predicted formulas of the design parameters were derived and eight models were employed to investigate the effectiveness of the formulas, in order to be applied in the seismic design.

scholarly journals Out-of-Plane Shaking Table Tests on Seismic Response of RC Frame Infilled with a New Type of Shale Fired Heat-Insulation Blocks

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Jian Wu ◽  
Li-dan Zhang ◽  
Qing Yu ◽  
Bo Wang
Keyword(s):  
Seismic Response ◽  
Heat Insulation ◽  
Masonry Wall ◽  
Shaking Table ◽  
Rc Frame ◽  
Out Of Plane ◽  
Rigid Connection ◽  
New Type ◽  
Infill Masonry ◽  
Insulation Block

Shale fired heat-insulation block, which is made of shale, fly ash, building rubbish, and waste paper, is a new type environment-friendly product. In order to study the mechanical properties of shale fired heat-insulation block walls, four full-scale walls were tested under El-Centro, Taft, and Ninghe earthquakes using shaking table equipment, in which the influence of the spacing of cast-in-place belt and the connection between the wall and the frame on the out-of-plane seismic performance of the wall was taken into account. The subject of this study is mainly about out-of-plane dynamic response of masonry walls in terms of frequency, displacement, and acceleration. It could be concluded that the cast-in-place belt and the rigid connection between wall and RC frame could effectively reduce the out-of-plane seismic response of the infill masonry wall. Finally, the recommendations for the use of this type of block in the structure are given.

scholarly journals Mechanical Properties of Full-Scale Prestressed Concrete Beams with Thin Slab after Exposure to Actual Fire

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Chaowei Hao ◽  
Yanjiang Chen ◽  
Yu Tang ◽  
Laiyong Wang
Keyword(s):  
Bearing Capacity ◽  
Prestressed Concrete ◽  
Concrete Beams ◽  
Rapid Identification ◽  
Ultimate Bearing Capacity ◽  
Full Scale ◽  
Bottom Surface ◽  
Thin Slab ◽  
Continuous Girder Bridge ◽  
Girder Bridge

To provide an effective basis and reference for applications of prestressed concrete thin-slab beams after a bridge fire, methods and principles of fire-resistant design, repair, and reinforcement of such beams were discussed. Taking a simple supported and continuous girder bridge of an expressway in service as a sample, appearance testing and nondestructive testing of the internal structure were carried out. Four representative full-scale prestressed concrete beams were selected. Through the comparative test of the ultimate bearing capacity of such beams, the laws of the deflection deformation, strain distribution, crack formation, and crack development were obtained. By combining with the finite element simulation and theoretical analysis, the ultimate bearing capacity, complex mechanical characteristics, and breakage feature and failure mechanism of such beams were studied. It was indicated by the results the following: (1) Prestress loss will cause height reduction of the concrete shear zone, which is one of the main reasons why the bending-shearing failure of such beams happened before the pure bending failure. (2) Under certain operating loads, brittle fracture is more likely to occur on the bottom surface of such beams when directly exposed to fire. (3) The bursting and spalling depth of concrete after being exposed to fire can be used as the characteristic parameters for the rapid identification of the bottom surface of such after-fire beams.

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