scholarly journals A Study on Axial Compression Performance of Large Diameter-Thickness Ratio Concrete-Filled Gas Drainage Steel Pipe

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Zi-Lu Liu ◽  
Zhan-Guo Ma ◽  
Ye Li ◽  
Peng Gong ◽  
Ke-Long Li ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Axial Compression ◽  
Ultimate Load ◽  
Peak Load ◽  
Steel Pipe ◽  
Load Bearing Capacity ◽  
Gas Drainage ◽  
Steel Pipes ◽  
Drainage Pipe ◽  
Second Peak

A large number of gas drainage pipes are obsoleted in the coal mine gas drainage system, and it causes serious waste. If concrete is poured into the discarded gas drainage pipes as components for underground roadway support, it is very significant for sustainable development of mine. Therefore, it is necessary to study the mechanical properties of the concrete-filled gas drainage steel pipe. Most frequently used gas drainage pipes are spiral welded steel pipe (SSP-I) and spiral external rib steel pipe (SSP-II). In this study, three different concrete-filled steel pipes are taken as the research object: SSP-I concrete-filled steel pipes, SSP-II concrete-filled steel pipes, and RSP concrete-filled ordinary round steel pipes. Through the axial compression test, the failure mode and relationship between stress-strain of concrete-filled steel pipes were obtained. Subsequently, the ultimate bearing capacity of three types of specimens was calculated based on the unified strength theory, limit equilibrium theory, and superposition theory. The test results show that both the SSP-I concrete-filled pipe columns and RSP concrete-filled pipe have good post-peak load-bearing capacity and ductility, and the second peak load reaches 70.38% and 81.92% of the ultimate load, respectively. The load-bearing capacity of SSP-II concrete-filled pipe columns is dropped sharply after bearing ultimate load, and the second peak load reaches only 36.47% of the ultimate load. The failure characteristics of concrete-filled gas drainage pipe columns show that the core concrete is compressed to powder and explain that the gas drainage pipe has fully exerted its restraint on the concrete. The FE method was used to simulate the compression test of three types of concrete-filled steel pipes, and the numerical simulation results show good agreement with the experimental results. Theoretical calculations show that the calculation of concrete-filled gas drainage pipe columns based on the superposition theory EC4-2004 is the closest to the measured value. Therefore, the EC4-2004 standard is recommended to calculate the ultimate bearing capacity of concrete-filled gas drainage pipe columns.

scholarly journals The energy absorption behavior of novel composite sandwich structures reinforced with trapezoidal latticed webs

2021 ◽  
Vol 60 (1) ◽  
pp. 503-518
Author(s):  
Juan Han ◽  
Lu Zhu ◽  
Hai Fang ◽  
Jian Wang ◽  
Peng Wu
Keyword(s):  
Bearing Capacity ◽  
Energy Absorption ◽  
Sandwich Structure ◽  
Ultimate Load ◽  
Sandwich Structures ◽  
Elastic Displacement ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Composite Sandwich ◽  
Composite Sandwich Structures

Abstract This article proposed an innovative composite sandwich structure reinforced with trapezoidal latticed webs with angles of 45°, 60° and 75°. Four specimens were conducted according to quasi-static compression methods to investigate the compressive behavior of the novel composite structures. The experimental results indicated that the specimen with 45° trapezoidal latticed webs showed the most excellent energy absorption ability, which was about 2.5 times of the structures with vertical latticed webs. Compared to the traditional composite sandwich structure, the elastic displacement and ultimate load-bearing capacity of the specimen with 45° trapezoidal latticed webs were increased by 624.1 and 439.8%, respectively. Numerical analysis of the composite sandwich structures was carried out by using a nonlinear explicit finite element (FE) software ANSYS/LS-DYNA. The influence of the thickness of face sheets, lattice webs and foam density on the elastic ultimate load-bearing capacity, the elastic displacement and initial stiffness was analyzed. This innovative composite bumper device for bridge pier protection against ship collision was simulated to verify its performance. The results showed that the peak impact force of the composite anti-collision device with 45° trapezoidal latticed webs would be reduced by 17.3%, and the time duration will be prolonged by about 31.1%.

Effect of Axial Compression Ratio on Ductility and Bearing Capacity of Specially Shaped Columns with HRB500 Reinforcement

2012 ◽  
Vol 204-208 ◽  
pp. 1066-1069
Author(s):  
Yan Jun Li ◽  
Ping Liu
Keyword(s):  
Bearing Capacity ◽  
Axial Compression ◽  
Compression Ratio ◽  
Ultimate Load ◽  
Deformation Capacity ◽  
Displacement Ductility ◽  
Yield Load ◽  
Axial Compression Ratio ◽  
Low Cyclic Loading ◽  
Specially Shaped Column

Four specially shaped columns with HRB500 reinforcement were tested under low cyclic loading. The hysteretic curve, yield load, ultimate load, displacement ductility and rigidity degradation were compared in order to research the effect of axial compression ratio on ductility and bearing capacity of specially shaped column with HRB500 reinforcement. It is shown that the axial compression ratio has greater influence on ductility and bearing capacity. With the increase of axial compression ratio, the bearing capacity of HRB500 reinforcement concrete specially shaped column can be enhanced while the deformation capacity becomes worse. The hysteretic characteristic of specially shaped columns with HRB500 reinforcement is improved and the stiffness degeneration becomes slow with the decrease of axial compression ratio.

Experimental and finite element study on the single-layer reticulated composite joints

2020 ◽  
Vol 23 (10) ◽  
pp. 2174-2187
Author(s):  
Liang Zheng ◽  
Cheng Qin ◽  
Hong Guo ◽  
Dapeng Zhang ◽  
Mingtan Zhou ◽  
...  
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Axial Compression ◽  
Wall Thickness ◽  
Great Influence ◽  
Single Layer ◽  
Experimental Results ◽  
Steel Pipe ◽  
Cover Plate ◽  
Element Analysis

In this article, a new type of reticulated joint, named the steel–concrete composite reticulated shell joint, is proposed. The proposed reticulated shell joint consists of an inner circular steel pipe, an outer circular steel pipe, a steel cover plate, and internal concrete. Five test specimens were tested under axial compression. The variable study included the wall thickness of the inner and outer circular steel pipes and the radius of the inner circular steel pipe. The test specimens exhibited a high bearing capacity and good plastic deformation ability under axial compression. The test results show that the wall thickness of the outer circular steel pipe and the radius of the inner circular steel pipe have a great influence on the bearing capacity of the steel–concrete composite reticulated shell joint, while the wall thickness of the inner circular steel pipe has little influence on the bearing capacity of the steel–concrete composite reticulated shell joint. Based on the test of the steel–concrete composite reticulated shell joints under axial load, the three-dimensional nonlinear finite element model was used to analyze the mechanical properties of the steel–concrete composite reticulated shell joints under axial compression. The results of the finite element analysis showed good agreement with the experimental results. The formula for calculating the bearing capacity of the joint is derived. By comparing with the experimental results, the calculated results are basically consistent with the experimental results.

Deformation Characteristics and Load-Bearing Capacity of NO.21 Coal Seam’s Mudstone Floor in Western Henan

2013 ◽  
Vol 644 ◽  
pp. 175-178
Author(s):  
Jing Ping Wei ◽  
Fan Chen ◽  
Zhi Hao Ding
Keyword(s):  
Plastic Deformation ◽  
Bearing Capacity ◽  
Peak Load ◽  
Layer By Layer ◽  
Specific Pressure ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Transition Mechanism ◽  
Failure State ◽  
Weak Plane

Through the floor specific pressure test, the floor specific pressure was obtained. The rock mass of mudstone, under the loading perpendicular to the weak plane, was in brittle-plastic failure state, and the bearing capacity of mudstone was equal to the Ⅲa grade floor. The brittle-plastic transition mechanism of the mudstone was revealed: Firstly, the more size, the more heterogeneity. The mudstone body was bigger than its rock samples, so there were more planes of weakness, which caused the macroscopic plastic deformation. Secondly, the directions of the load and the weak plane influenced the strength of the mudstone floor. During the plastic deformation, the compressive failure occurred layer by layer under the loading perpendicular to the weak planes, and the post peak load-bearing capacity of mudstone floor was decided by the layer’s strength.

FINITE ELEMENT ANALYSES ON CORRODED PONY TRUSS BRIDGE FOR REASONABLE MAINTENANCE

2020 ◽  
Vol 7 (2) ◽  
Author(s):  
Risa Fujinaga ◽  
Tatsumasa Kaita ◽  
Ryoko Koyama ◽  
Tsutomu Imai ◽  
Katashi Fujii
Keyword(s):  
Bearing Capacity ◽  
Ultimate Load ◽  
Plane Deformation ◽  
Element Model ◽  
Truss Structures ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Out Of Plane ◽  
Pony Truss Bridge ◽  
Truss Bridge

The load bearing capacity of an existing corroded pony truss bridge, which is used for 100 years was estimated from FEM results for whole bridge model. The beam element model is to clarify that the influence of the residual out-of-plane deformation in main truss structures on the load bearing capacity from the viewpoint of whole bridge. Also, shell element model is to clarify that the influence of severe corrosion damages occurred in many structural members on the load bearing capacity as whole bridge. On the other hand, the influence of assumed support conditions in analytical models were discussed from the analytical results of both type of models, because it will be thought that the performance of shoes deteriorates gradually by long in-service period. The ultimate load bearing capacity was estimated by the critical live load magnification. From the analytical results, the residual out-of-plane deformation of main truss structures in this bridge had little influence on the ultimate load bearing capacity. Also, the ultimate load bearing capacity may decrease up to 20% due to aging deterioration of shoes including corrosion damages. In bridge maintenance, it should be paid attention on local severe corrosion damages on the structural member, which may occur higher secondary stress.

scholarly journals Assessment of Seismic Bearing Capacity of a Strip Footing Resting on Reinforced Earth Bed using Pseudo-Static Analysis

2021 ◽  
Vol 31 (2) ◽  
pp. 117-137
Author(s):  
Sagar Jaiswal ◽  
Vinay Bhushan Chauhan
Keyword(s):  
Bearing Capacity ◽  
Dynamic Loading ◽  
Ultimate Load ◽  
Strip Footing ◽  
Shallow Foundation ◽  
Coarse Grained ◽  
Geosynthetic Reinforcement ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Dense Sand

Abstract The use of geosynthetic reinforcement to enhance the ultimate load-bearing capacity and reduce the anticipated settlement of the shallow foundation has gained sufficient attention in the geotechnical field. The improved performance of the shallow foundation is achieved by providing one or more layers of geosynthetics below the foundation. The full wraparound technique proved to be efficient for the confinement of soil mass and reduction in settlement of foundation however lacks the literature to ascertain the performances of such footing under dynamic loading. In view of the above, the present study examines the effect of geosynthetic layers having a finite length with full wraparound ends as a reinforcement layer, placed horizontally at a suitable depth below the foundation using the finite element modeling (FEM) and evaluates the ultimate load-bearing capacity of a strip footing resting on loose and dense coarse-grained earth beds under seismic loading and further compared to those of footing resting on unreinforced earth bed. Moreover, the effect of horizontal seismic acceleration coefficient (kh) on the ultimate load-bearing capacity has been investigated by varying kh from 0.1 to 0.6 at an interval of 0.1, for both reinforced and unreinforced earth bed having loose and dense soil strata. Furthermore, this study demonstrates that by adopting the new practice of using the geosynthetic reinforcement with the full wraparound ends in foundations, it is possible to support relatively heavier structures under static as well as dynamic loading without allowing large footing settlements. From the outcomes of the present study, it is noted that the ultimate load-bearing capacity of footing resting on loose and dense sand bed found to be improved by 60% and 18% for soils having friction angle of 25° and 40°, respectively compared to respective unreinforced earth beds under static condition.

Experimental Study on Residual Load Bearing Capacity of SRC Eccentric Columns after Exposure to Fire

2010 ◽  
Vol 163-167 ◽  
pp. 2240-2246 ◽  
Author(s):  
Jun Hua Li ◽  
Yue Feng Tang ◽  
Ming Zhe Liu
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Ultimate Strength ◽  
Room Temperature ◽  
Ultimate Load ◽  
Flexural Rigidity ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Steel Reinforced Concrete

This paper provided three test data pertaining to the mechanical properties of steel reinforced concrete (SRC) eccentric columns after exposure to fire and one comparative test data pertaining to the mechanical properties of steel reinforced concrete columns at room temperature. The influence of eccentricity on failure mode, distortion performance and ultimate load bearing capacity are mainly studied. Test results show that the failure modes of steel reinforced concrete eccentric columns after exposure to fire are similar to that at room temperature. Strain along the section height at mid-span section of eccentric columns before loaded to 90% ultimate load bearing capacity is linearly distributed and well agree with the plane section supposition. After exposure to fire, the flexural rigidity and load bearing capacity of specimens are all declined compared with that at normal temperature. In various loading stages from the initial loading to 80% ultimate strength, the ratio of flexural rigidity of SRC eccentric columns after exposure to fire and at normal temperature is ranged from 0.30 to 0.59. With the same concrete strength and heating condition, the ultimate strength of specimens decreases with the increasing of eccentricity. The ultimate bearing capacity of all specimens at normal room temperature is calculated on the method proposed by Chinese regulation JGJ 138-2001. The compared results of experimental values and calculating values show that the residual load bearing capacity of SRC eccentric columns after exposure to fire is about 69% to 81% of that at room temperature.

scholarly journals Structural performance of textile reinforced concrete sandwich panels under axial and transverse load

2021 ◽  
Vol 60 (1) ◽  
pp. 64-79
Author(s):  
Junqing Hong ◽  
Shaofeng Zhang ◽  
Hai Fang ◽  
Xunqian Xu ◽  
Honglei Xie ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Failure Modes ◽  
Ultimate Load ◽  
Wire Mesh ◽  
Transverse Load ◽  
Composite Panels ◽  
Textile Reinforced Concrete ◽  
Load Bearing Capacity ◽  
Load Bearing

Abstract The performance of textile reinforced concrete composite panels (TRCCPs) under the action of pseudo-static load up to collapse was evaluated. The test of TRCCPs under axial and transverse loading was conducted, and the results were compared with those for steel wire mesh reinforced-concrete composite panels (SMRCCPs). Ceram-site concrete was utilized as the panel matrix owing to its lightweight and insulation characteristics. The ultimate load bearing capacity, load-deformation and load-strain relationships, and failure modes were discussed and investigated in comparison with the findings of non-linear finite-element-model (FEM) analysis and the analytic method on the basis of the reinforced concrete (RC) theory. The analysis results indicate that TRCCP is suitable for use as a potential structural member for a wall or slab system of buildings, and the typical RC theory can be applied to predict the ultimate load bearing capacity if modified suitably.

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