Research on Mechanical Property and Economic Effect of Contractible Concrete Filled Steel Tube Support

2011 ◽  
Vol 90-93 ◽  
pp. 722-727
Author(s):  
Hui Li ◽  
Bei Jiang ◽  
Bin Yang ◽  
Qi Wang ◽  
Hong Tao Wang ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Bearing Capacity ◽  
Influencing Factor ◽  
Economic Effect ◽  
Soft Rock ◽  
Economic Benefits ◽  
Steel Tube ◽  
Support Effect ◽  
Optimization Analysis ◽  
Concrete Filled Steel Tube

The finite models of U-steel support, grid steel frame, hollow steel tube support and concrete filled steel tube support were established, of which mechanical property and influencing factor such as bearing capacity, support effect etc. was analyzed. Comparative analysis of economic benefit was carried out through research of material dosage and support effect index. The contractible joint for concrete filled steel tube was designed, and their mechanical characteristic was analyzed through test. The results show that the supporting performance of concrete filled steel tube support is related to confinement coefficient. Compared with traditional support, the concrete filled steel tube support has high bearing capacity, intensive later strength, good ductility, various standards and well economic benefits, and in conjunction with contractible joint, it is able to implement functions of quantitatively increasing resistance and yielding. Properly designed through optimization analysis on associated effects, the concrete filled steel tube support can meet supporting demand of deep soft rock and joint broken rock.

Supporting Effect and Economic Benefit Analysis on New Type Concrete-Filled Steel Tube Supports

2010 ◽  
Vol 160-162 ◽  
pp. 608-613
Author(s):  
Qi Wang ◽  
Bei Jiang ◽  
Shu Cai Li ◽  
Han Peng Wang ◽  
Wei Teng Li ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Economic Benefit ◽  
Mechanical Performance ◽  
Soft Rock ◽  
Jointed Rock ◽  
Steel Tube ◽  
Engineering Practice ◽  
Contrast Model ◽  
Concrete Filled Steel Tube ◽  
Relative Design

The finite element contrast model such as concrete filled steel tube support, U-steel support and hollow steel tube support were established with ANSYS software, combining with engineering practice and relative design scheme of concrete filled steel tube test, respectively analysis their influencing factors and mechanical properties such as support effect, bearing capacity and so on. The economic benefit of each support was been analysised by comprehensive comparison of the material using condition and mechanical performance. The results show that, comparing with traditional U-steel support, retractable concrete filled steel tube support is a new style support with high bearing capacity, a large variety of sizes, higher economic benefit, and hence fit to support the deep soft rock broken jointed rock mass.

Experiment and Application Study on the Load-Bearing Properties of Shallow Arch Circular Concrete Filled Steel Tube Support

2014 ◽  
Vol 568-570 ◽  
pp. 1662-1666
Author(s):  
Jun Wang ◽  
Yan Fa Gao
Keyword(s):  
Bearing Capacity ◽  
Soft Rock ◽  
Steel Tube ◽  
Shallow Arch ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Concrete Filled Steel Tube ◽  
Theoretical Test ◽  
Soft Rock Roadway ◽  
Rock Roadway

Shallow arch circular concrete filled steel tube support has a good load-bearing capacity, which is used in soft rock roadway supporting to solve the problem of supporting instability and to reduce the amount of anti-invert excavation. In this paper, concrete filled steel tube supports of Φ168 ×6 are designed according to shallow arch circular concrete filled steel tube structures and their load-displacement curves, ultimate bearing capacity and support failure mode are especially tested in experiment. This shallow arch circular concrete filled steel tube support is also applied in very soft rock roadway supporting of No. 1 mine well of Chaganzhuoer in Xilinhot, Inner Mongolia and proved to be of good supporting effect. The shallow arch circular concrete filled steel tube support is of higher load-bearing capacity and of outstanding advantages in solving extremely soft rock roadway supporting problems, as is proved in both theoretical test and application.

scholarly journals Research on Influence Factors of Bearing Capacity of Concrete-Filled Steel Tubular Arch for Traffic Tunnel

Symmetry ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 167
Author(s):  
Lei Li ◽  
Ke Lei
Keyword(s):  
Bearing Capacity ◽  
Influence Factors ◽  
Soft Rock ◽  
Economic Benefits ◽  
Steel Tube ◽  
Underground Engineering ◽  
Supporting Structure ◽  
Geological Conditions ◽  
Traffic Tunnel ◽  
Core Concrete

When a traffic tunnel passes through special strata such as soft rock with high geo-stress, expansive rock, and fault fracture zones, the traditional supporting structure is often destroyed due to complicated loads, which threatens the construction and operation safety of tunnel engineering. Concrete-filled steel tubular (CFST) structure gives full play to the respective advantages of steel and concrete and has better bearing capacity and economic benefits than traditional support structure, which has achieved good results in some underground engineering applications. In order to promote the application of CFST in the construction of traffic tunnels with complex geological conditions and improve the bearing capacity of the initial supporting structure of tunnels, the influencing factors of the bearing capacity of CFST arch were studied by numerical simulation. The main achievements are as follows: (1) The load-displacement curves of CFST members under different material parameters are basically consistent. CFST members have significant restrictions on displacement in the elastic stage and have high ultimate bearing capacity. Although the bearing capacity decreases obviously after reaching the peak, it shows good extension performance. (2) The height of the steel tube section, the thickness of the steel tube wall and the grade of the core concrete have an approximately linear positive correlation with the bearing capacity of CFST arch, but the influence of these three factors on the bearing capacity of CFST arch decreases in turn, and when the grade of core concrete increases above C50, it has no significant effect on the bearing capacity of members.

Bearing capacity of composite shear wall incorporating a concrete-filled steel tube boundary and column-type reinforced wall

2020 ◽  
Vol 23 (10) ◽  
pp. 2188-2203
Author(s):  
Zhao Nannan ◽  
Wang Yaohong ◽  
Han qing ◽  
Su Hao
Keyword(s):  
Bearing Capacity ◽  
Residual Deformation ◽  
Shear Walls ◽  
Shear Wall ◽  
Steel Tube ◽  
Concrete Filled Steel Tube ◽  
Composite Shear Wall ◽  
Boundary Shear ◽  
Column Type ◽  
Composite Shear

Composite shear walls are widely used in high-rise buildings because of their high bearing capacity. To improve the bearing capacity of ordinary shear walls, restraining elements are usually installed at both boundaries or within the wall body. In this article, two different restraining elements, namely, a rectangular steel tube and a column-type reinforcement (the whole wall body was restrained by segmented stirrups and tied by diagonal bars), were applied to the boundary frame and wall body of the shear wall either jointly or separately. A new type of steel-concrete composite shear wall, referred to as a composite shear wall incorporating a concrete-filled steel tube boundary and column-type reinforced wall, was proposed. In addition, three specimens with different restraining elements, namely, a column-type reinforced shear wall, a concrete-filled steel tube boundary shear wall and an ordinary reinforced concrete shear wall, were presented for comparison. The influences of the two different restraining elements on the seismic performance and bearing capacity of the shear walls were analyzed from four perspectives of failure mode, hysteresis behavior, stiffness and residual deformation, and the equivalent lateral pressures of the two restraining elements were calculated. Based on the plane-section assumption, expressions for the crack, yield, peak and ultimate bearing capacities were derived, and the effects of the two restraining elements on the peak and ultimate bearing capacities were considered. The results show that these two restraining elements significantly improved the bearing capacity of the shear wall specimens, and the concrete-filled steel tube restraining element was more effective than the column-type reinforced restraining element. Finally, the calculated values of the bearing capacity of the four different restraining elements of the shear wall specimens proposed in this article were in good agreement with the experimental values.

Study of the Ultimate Bearing Capacity of Concrete-filled Steel Tube K-Joints

2019 ◽  
Vol 23 (5) ◽  
pp. 2254-2262 ◽  
Author(s):  
Kaizhong Xie ◽  
Hongwei Wang ◽  
Jinhao Pang ◽  
Jianxi Zhou
Keyword(s):  
Bearing Capacity ◽  
Steel Tube ◽  
Ultimate Bearing Capacity ◽  
Concrete Filled Steel Tube

Axial behaviour of slender concrete-filled steel tube square columns strengthened with square concrete-filled steel tube jackets

2019 ◽  
Vol 23 (6) ◽  
pp. 1074-1086 ◽  
Author(s):  
Tao Zhu ◽  
Hongjun Liang ◽  
Yiyan Lu ◽  
Weijie Li ◽  
Hong Zhang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Bearing Capacity ◽  
Element Model ◽  
Steel Tube ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Concrete Filled Steel Tube ◽  
Experimental Parameters ◽  
Modified Formula

This article investigates the behaviour of slender concrete-filled steel tube square columns strengthened by concrete-filled steel tube jacketing. The columns were realised by placing a square outer steel tube around the original slender concrete-filled steel tube column and pouring strengthening concrete into the gap between the inner and outer steel tubes. Three concrete-filled steel tube square columns and seven retrofitted columns ranging from 1200 to 2000 mm were tested to failure under axial compression. The experimental parameters included three length-to-width ( L/ B1) ratios, three width-to-thickness ( B1/ t1) ratios and three strengths of concrete jacket (C50-grade, C60-grade and C70-grade). Experimentally, the retrofitted columns failed in a similar manner to traditional slender concrete-filled steel tube columns. After strengthening, the retrofitted columns benefitted greatly from the component materials, with their load-bearing capacity and ductility notably enhanced. These enhancements were mainly brought about by sectional enlargement and good confinement of concrete. A finite element model was developed using ABAQUS to better understand the axial behaviour of the retrofitted specimens. A parametric study was conducted, with parameters including the length of the column, thickness of the outer steel tube, strength of the concrete jacket, yield strength of the outer steel tube, thickness of the inner steel tube and strength of the inner concrete. Furthermore, the finite element model was adopted to study the behaviour of rust-damaged and post-fire slender concrete-filled steel tube square columns strengthened by square concrete-filled steel tube jacketing. A modified formula was proposed to predict the load-bearing capacity of retrofitted specimens, and the numerical results agreed well with the experiments and the finite element results of undamaged, rust-damaged and post-fire specimens. It could be used as a reference for practical application.

scholarly journals The Horizontal Bearing Capacity of Composite Concrete-Filled Steel Tube Piles

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Yunxiu Dong ◽  
Zhongju Feng ◽  
Haibo Hu ◽  
Jingbin He ◽  
Qilang Zhang ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Soil Compaction ◽  
Soil Mass ◽  
Steel Tube ◽  
Continuous Increase ◽  
Concrete Filled Steel Tube ◽  
Concrete Piles ◽  
Compaction Zone ◽  
Reinforced Concrete Piles ◽  
Centrifugal Model

Steel casings (SCs) are extensively and increasingly used to stabilize the borehole wall in the construction of bridge pile foundations. Steel casings (SCs), together with reinforced concrete piles (RCPs), form composite concrete-filled steel tube piles (CCFSTPs), which differ significantly from ordinary RCPs in horizontal bearing capacity. In this study, based on the characteristics of CCFSTPs, the horizontal bearing capacity of a CCFSTP was examined through a centrifugal model test with the length of the steel casing (LSC) and the modulus of the soil mass in the steel casing soil compaction zone (ESCSC_zone) as variables. Pile-side soil resistance, load-displacement curves, and pile moment curves were obtained for the CCFSTP. The results show that increasing LSC within a range of 12 cm significantly increases the ultimate horizontal bearing capacity of the CCFSTP, and further increasing LSC beyond 12 cm produces a continuous increase in the ultimate horizontal bearing capacity of the CCFSTP but only to an insignificant extent. In addition, increasing ESCSC_zone increases the ultimate horizontal bearing capacity of the CCFSTP, but to a relatively small extent. The results of this study provide a theoretical basis and technical support for the design and construction of CCFSTPs.

scholarly journals Axial Compression Performance of Square Thin Walled Concrete-Filled Steel Tube Stub Columns with Reinforcement Stiffener under Constant High-Temperature

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1098 ◽  
Author(s):  
Xuetao Lyu ◽  
Yang Xu ◽  
Qian Xu ◽  
Yang Yu
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Bearing Capacity ◽  
Numerical Models ◽  
Steel Tube ◽  
Ultimate Bearing Capacity ◽  
Displacement Curve ◽  
Concrete Filled Steel Tube ◽  
Finite Element Software ◽  
Thin Walled

This study investigated the axial compressive performance of six thin-walled concrete-filled steel tube (CFST) square column specimens with steel bar stiffeners and two non-stiffened specimens at constant temperatures of 20 °C, 100 °C, 200 °C, 400 °C, 600 °C and 800 °C. The mechanical properties of the specimens at different temperatures were analyzed in terms of the ultimate bearing capacity, failure mode, and load–displacement curve. The experiment results show that at high temperature, even though the mechanical properties of the specimens declined, leading to a decrease of the ultimate bearing capacity, the ductility and deformation capacity of the specimens improved inversely. Based on finite element software ABAQUS, numerical models were developed to calculate both temperature and mechanical fields, the results of which were in good agreement with experimental results. Then, the stress mechanism of eight specimens was analyzed using established numerical models. The analysis results show that with the increase of temperature, the longitudinal stress gradient of the concrete in the specimen column increases while the stress value decreases. The lateral restraint of the stiffeners is capable of restraining the steel outer buckling and enhancing the restraint effect on the concrete.

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