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

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.

2011 ◽  
Vol 90-93 ◽  
pp. 722-727
Author(s):  
Hui Li ◽  
Bei Jiang ◽  
Bin Yang ◽  
Qi Wang ◽  
Hong Tao Wang ◽  
...  

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.


2013 ◽  
Vol 838-841 ◽  
pp. 1884-1890 ◽  
Author(s):  
Guang Long Qu ◽  
Yan Fa Gao ◽  
Liu Yang ◽  
Bin Jing Xu ◽  
Guo Lei Liu ◽  
...  

Compared with I-shaped and U-shaped supports in soft rock roadway, concrete-filled steel tubular (CFST) support, as a new supporting form, has stronger bearing capacity with reasonable price. So it is becoming more and more popular in roadway supporting of coal mine in China. In this article, the surrounding rock in soft rock roadway was classified into three different types: hard rock in deep coal mine, soft surrounding rock, extremely soft surrounding rock. And, according to the characteristics of deformation failure of the CFST support and the surrounding rock in the industrial tests, three different strength assessments, including assessment of axial compressive strength, assessment of lateral flexural performance, assessment of hardening rate of core concrete, were proposed through mechanical analysis and laboratory tests for the three different types of the surrounding rock, respectively. Moreover, aimed to insufficient flexural strength of the support or low hardening rate of the core concrete in some of the roadway supporting, strengthening lateral flexural performance or making early strength concrete was necessary for the above unfavorable situations. The laboratory test results showed that the ultimate bearing capacity for the CFST support with φ194*8mm of steel tube reinforced by φ38mm round steel was 31% greater than that of the unreinforced one, 177% greater than that of the U-shaped one with equivalent weight per unit length.


2014 ◽  
Vol 1065-1069 ◽  
pp. 1092-1096 ◽  
Author(s):  
Gao Cheng ◽  
Yong Jian Liu ◽  
Lei Jiang

Concrete-filled rectangular steel tube four sides restraint effect on the core concrete was weaker than the corner, which made the effect not significant. The paper studied a new kind of stiffening rib –PBL stiffener to strengthen restraint effect of concrete-filled rectangular steel tube , and evaluated its advantages compared with other stiffening ribs. 9 PBL stiffened concrete-filled rectangular steel tube columns under axial compressive load were tested. It also collected the test with other stiffened rids, such as straight ribs, binding bars, knee brace, steel reinforcement cage, steel bar stiffeners, saw tooth shaped stiffeners, stitching straight stiffeners and no rib concrete filled rectangular steel tube to compare. It evaluated increasing coefficient of bearing capacity by stiffening ribs. The results showed that: the PBL stiffeners and binding bar of concrete-filled rectangular steel tube bearing capacity was greater than other reinforcement measures by more than 20%; PBL stiffener could be a new prominent type of stiffener because of its excellent mechanical performance and simple construction.


2011 ◽  
Vol 368-373 ◽  
pp. 369-372
Author(s):  
Zhu Yan Li ◽  
Yong Jun Liu ◽  
Dong Wang

The tests are order to investigate the axial compressive performance of the new circular hybrid Steel-Concrete- CFRP-Concrete column (simply called SCCC column).SCCC column is composed of steel tube, annular concrete, CFRP tube and core concrete. Axial ultimate bearing capacity test was performed on 3 SCCC columns, from which we gains the law of affecting SCCC columns, the load-strain curve and load-displacement curve of SCCC columns, and compare the test results of the test specimen with different annular concrete thicknesses, from which we finds that after the relationship curve of test specimen with small annular concrete thickness reaches yield load, the bearing capacity starts to decline, and then continues to rise till the ultimate load is reached and the test specimen is damaged. The result shows that the smaller the annular concrete thickness is, the greater the axial ultimate bearing capacity of SCCC column is, and also indicates that CFRP tube plays a role of binding and constraining to the core concrete in later period of loading the test specimens.


2013 ◽  
Vol 690-693 ◽  
pp. 742-746
Author(s):  
Peng Wu ◽  
Jian Feng Xu ◽  
Jun Hai Zhao ◽  
Qian Zhu ◽  
Su Wang

Based on unified strength theory, the mechanical behavior of core-concrete of concrete-filled square steel tubular stub columns was analyzed. Through controlling the constraint effect between square steel tube and core-concrete by width-thickness ratio, the ultimate bearing capacity formula for concrete-filled square steel tubular stub columns under axial compression was proposed, and the influencing factors of which was also discussed. The rationality of proposed formula was proved from the comparison of the analytical results obtained in this paper and experimental data.


2014 ◽  
Vol 1065-1069 ◽  
pp. 1341-1344
Author(s):  
Gao Lei ◽  
Rui Wang

Concrete filled double skins steel tube is a new components which is based on concrete filled steel tubular and use inner steel tube instead of core concrete. The components have many advantages such as little weight, good resistance for earthquake, good stiffness for resist bending and good performance for resist fire, and has been used in bridge pier, high-rise buildings, power transmission tower and so on. While these structures may inevitably suffer impact which comes from vehicles, ships, aircraft, etc. the structures which is impacted have taken much attention. This article will analysis dynamic behavior of concrete filled double steel tube under impact with simply supported, and propose formula of dynamic bearing capacity, laid the foundation for the analysis of impact performance of CFDST.


2011 ◽  
Vol 243-249 ◽  
pp. 1272-1278
Author(s):  
Tian Hua Li ◽  
Jun Hai Zhao ◽  
Xue Ying Wei ◽  
Wei Kong ◽  
Xiao Ming Dong

Based on the unified strength theory, the bearing capacity of the concrete filled square steel tube short columns with inner CFRP circular tube under eccentric compression was analyzed. The restriction effect of the inner CFRP circular tube upon the core concrete, strength reduction factor for eccentricity ratio and the equivalent reduction factor, which considered the ratio of thickness to side effect, were taken into account in the theoretical analysis. The axial bearing capacity formula of the square steel tube short columns filled with inner CFRP circular tube was deduced. By introducing the strength reduction factor for eccentricity ratio, the eccentric bearing capacity formula on the basis of the axial bearing capacity formula was obtained. Parametric studies were carried out to evaluate the effects of intermediate principal stress, different CFRP deployment ratios, eccentricity ratios and the tension-compression ratio on the eccentric bearing capacity of the column. The formula was verified by the comparison of the theoretical results with the experimental data. The results show that inner CFRP circular tube can effectively restrain the core concrete.


2015 ◽  
Vol 744-746 ◽  
pp. 432-436
Author(s):  
Jie Liu ◽  
Fu An Huang ◽  
Qing Guang Yang ◽  
Bin Cui

In order to improve the bearing behavior and the bearing capacity of single pipe pile, the technology of step cross-section pipe-pile is proposed.Based on FLAC3D, the finite difference model of the pile-soil interaction established,bearing behaviors of step cross-section pipe pile and unimate cross-section pipe pile is studied comparatively and bearing performance influence factors of step cross-section pipe pile is discussed.The results show that the bearing capacity of step cross-section pipe pile is much higher than unimate cross-section pipe pile in the same geological conditions and material dosage. For layered foundation, the bearing capacity of single pile may be improved by setting variable cross-section pile joint in relatively hard soil. But the depth of joint embedded in hard soil has little influence on bearing capacity of single pile.There is an obvious effect on increasing capacity of single pile by improving soil properties of soft soil surrounding pile.


2010 ◽  
Vol 160-162 ◽  
pp. 608-613
Author(s):  
Qi Wang ◽  
Bei Jiang ◽  
Shu Cai Li ◽  
Han Peng Wang ◽  
Wei Teng Li ◽  
...  

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.


2012 ◽  
Vol 588-589 ◽  
pp. 212-216
Author(s):  
Rui Jing ◽  
Yong Sheng Zhang

With the help of large general finite element analysis software ANSYS, under different parameters, this paper will have a finite element analysis of bearing capacity on circular steel tube compile short column filled with steel reinforced concrete(STCSRC).In the paper,it uses separate models to calculate and analyze.Considering the nonlinear constitutive relation of steel and concrete and determining the type of unit,it is shown that stress distribution and load-displacement curve of specimen under the effect of different parameters.According to the curve and data,analysis results of bearing capacity of specimen have been shown that bearing capacity of STCSRC will increase with concrete strength increasing and it also will increase with steel rate increasing under axial load.Because of core concrete working together with steel tube and angle steel,it can significantly improve the bearing capacity of composite columns, slow down and inhibit shearing inclined cracks occur in the core concrete and develop,and improve the ductility of columns.


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