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Article
Publication date: 3 February 2020

Hamed Arefizadeh and Hadi Shahir

Anchorage with concrete bearing pad is commonly used in Iran for stabilization of excavations because of the ease of construction, less costs and less time consumption than the…

Abstract

Purpose

Anchorage with concrete bearing pad is commonly used in Iran for stabilization of excavations because of the ease of construction, less costs and less time consumption than the soldier pile method. In this method, a wall facing which includes the concrete bearing pads at the location of the anchors and a shotcrete layer between the bearing pads is constructed parallel to the excavation operation similar to the nailing method.

Design/methodology/approach

In this paper, using the finite element software Abaqus, a three-dimensional model of the above-mentioned type of wall is constructed, and the effect of spacing and size of bearing pads on the wall behavior is discussed.

Findings

According to the obtained results, the size of the concrete bearing pads has little effect on wall deformations, but the internal forces and bending moments developed in the shotcrete layer between the bearing pads are greatly influenced by the bearing pads dimensions and spacing.

Originality/value

Owing to the discrete elements of the wall facing, the behavior of this system is completely three-dimensional.

Details

Journal of Engineering, Design and Technology , vol. 18 no. 6
Type: Research Article
ISSN: 1726-0531

Keywords

Article
Publication date: 27 September 2022

Yong Huang, Guangyou Song and Guochang Li

The purpose of this study is to explore the seismic damage mechanism of the Dayemaling Bridge during the Maduo earthquake and discuss the seismic damage characteristics of the…

Abstract

Purpose

The purpose of this study is to explore the seismic damage mechanism of the Dayemaling Bridge during the Maduo earthquake and discuss the seismic damage characteristics of the high-pier curved girder bridge.

Design/methodology/approach

In this study, the numerical simulation method is used to analyze the seismic response using synthetic near-field ground motion records.

Findings

The near-field ground motion of the Maduo earthquake has an obvious directional effect, it is more likely to cause bridge seismic damage. Considering the longitudinal slope of the bridge and adopting the continuous girder bridge form, the beam end displacement of the curved bridge can be effectively reduced, and the collision force of the block and the bending moment of the pier bottom are reduced, so the curved bridge with longitudinal slope is adopted.

Originality/value

Combined with the seismic damage phenomenon of bridges in real earthquakes, the seismic damage mechanism and vulnerability characteristics of high-pier curved girder bridges are discussed by the numerical simulation method, which provides technical support for the application of such bridges in high seismic intensity areas.

Details

Multidiscipline Modeling in Materials and Structures, vol. 18 no. 6
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 22 August 2022

Long Liu and Songqiang Wan

To make full use of the tensile strength of near surface mounting (NSM) pasted carbon fiber reinforced plastics (CFRP) strips and further increase the flexural bearing capacity…

89

Abstract

Purpose

To make full use of the tensile strength of near surface mounting (NSM) pasted carbon fiber reinforced plastics (CFRP) strips and further increase the flexural bearing capacity and flexibility of reinforced concrete (RC) beams, a new composite reinforcement method using ultra-high performance concrete (UHPC) layer in the compression zone of RC beams is submitted based on embedding CFRP strips in the tension zone of RC beams. This paper aims to discuss the aforementioned points.

Design/methodology/approach

The experimental beam was simulated by ABAQUS, and compared with the experimental results, the validity of the finite element model was verified. On this basis, the reinforced RC beam is used as the control beam, and parameters such as the CFRP strip number, UHPC layer thickness, steel bar ratio and concrete strength are studied through the verified model. In addition, the numerical calculation results of yield strength, ultimate strength, failure deflection and flexibility are also given.

Findings

The flexural bearing capacity of RC beams supported by the new method is 132.3% higher than that of unreinforced beams, and 7.8% higher than that of RC beams supported only with CFRP strips. The deflection flexibility coefficient of the new reinforced RC beam is 8.06, which is higher than that of the unreinforced beam and the reinforced concrete beam with only CFRP strips embedded in the tension zone.

Originality/value

In this paper, a new reinforcement method is submitted, and the effects of various parameters on the ultimate bearing capacity and flexibility of reinforced RC beams are analyzed by the finite element numerical simulation. Finally, the effectiveness of the new method is verified by the analytical formula.

Details

International Journal of Building Pathology and Adaptation, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2398-4708

Keywords

Article
Publication date: 6 September 2022

Lifeng Wang, Haiqi Wu, Long Liu and Ziwang Xiao

The application of ultra-high performance concrete (UHPC) in anchorage zones can significantly improve the local compression performance of structures. However, the high cost and…

Abstract

Purpose

The application of ultra-high performance concrete (UHPC) in anchorage zones can significantly improve the local compression performance of structures. However, the high cost and complex preparation of UHPC make UHPC difficult to be widely used in practice. This study proposes a method to strengthen the local compression zone of structures built by normal strength concrete (NSC) by incorporating UHPC cores.

Design/methodology/approach

In this study, a Finite Element Model (FEM) of local compression specimens was established by ABAQUS, and the accuracy of FEM was verified by comparing the FEM calculation results with experimental results. The verified FEM was adapted to the research on the influences of affecting factors on local compression performance of structures, including NSC strength, UHPC strength, spiral steel bar strength, and UHPC core diameter.

Findings

The results show that the peak load of the strengthened specimen SC1-U + N increases by 210.2% compared to that of the SC1-NSC. Furthermore, compared to SC1, the strengthened specimen SC1-U + N can save 64.7% amount of UHPC while the peak load decreases by only 34.4%. The peak load of the strengthened specimens increases with the axial compressive strength and the diameter of UHPC cores increasing, crack load increases with increasing the compressive strength of NSC, the spiral steel bar with high strength can prevent the sharp drop of load-deflection curve and the residual bearing capacity increases accordingly. All findings indicate that increasing the diameter of UHPC cores can improve the overall performance of the specimens. Under loading, all specimens fail by following a similar pattern. The effectiveness of this new strengthen method is also verified by FEM analytical calculations.

Originality/value

Based on the experimental study, this study extrapolates the influence of different parameters on the local bearing capacity of the strengthened specimens by finite element simulation. This method not only ensures the accuracy of bearing capacity assessment, but also does not require many samples, which ensures the economy of the reinforcement process. The research results provide a reference for the reinforcement design of anchorage zone.

Details

Multidiscipline Modeling in Materials and Structures, vol. 18 no. 5
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 1 February 1976

Arthur M. Johnston

The exceptional frictional characteristics of PTFE (polytetrafluoroethylene) make it an ideal material for use as a sliding medium when moving heavy loads. Extremely low friction…

Abstract

The exceptional frictional characteristics of PTFE (polytetrafluoroethylene) make it an ideal material for use as a sliding medium when moving heavy loads. Extremely low friction coefficients can be achieved with pads and slideways made from unfilled PTFE so that massive loads can be moved with relatively small forces. The use of filled grades of PTFE can provide greatly increased wear resistance with a small increase in friction coefficient.

Details

Industrial Lubrication and Tribology, vol. 28 no. 2
Type: Research Article
ISSN: 0036-8792

Article
Publication date: 6 July 2022

Baocheng Liu, Jinliang Liu, Yanqian Wen, Qinglin Hu, Liang Liu and Shili Zhao

In this paper, to obtain shear and bending performance of carbon fiber-reinforced polymer (CFRP)-strengthened beams bonded by geopolymers, the effects of impregnated adhesive…

Abstract

Purpose

In this paper, to obtain shear and bending performance of carbon fiber-reinforced polymer (CFRP)-strengthened beams bonded by geopolymers, the effects of impregnated adhesive types, strengthened scheme, CFRP layer and pre-cracked width are investigated, and the performance of CFRP-strengthened beams is validated by the establishment of Finite Element Models (FEMs).

Design/methodology/approach

In this paper, static loading test and finite element analysis of epoxy-CFRP-strengthened (ECS) and geopolymer-CFRP-strengthened (GCS) were carried out, and the bearing capacity and stiffness were compared, the results show that GCS reinforced concrete (RC) beam is feasible and effective.

Findings

The bearing capacity, crack distribution and development, load–deflection curves of GCS RC beams with different pre-crack widths were investigated. The reinforcement effect of geopolymer achieves the same as epoxy, effectively improving the ultimate bearing capacity of the beam, with a maximum increase rate of 28.9%. The failure mode of CFRP is broken in the yield failure stage of GCS RC beam with reasonable strengthening form, and the utilization rate of CFRP is improved. CFRP-strengthened layers, pre-cracked widths significantly affect the mechanical properties, and deformation properties of the strengthened beams.

Originality/value

Compared with ECS RC beams, the bearing capacity and stiffness of GCS RC beams are similar to or even better, indicating that GCS RC beam is feasible and effective. It is a new method for CFRP-strengthened beams, which not only conforms to the concept of national ecological civilization construction, but also provides an economical, environmentally friendly and excellent performance solution for structural reinforcement.

Details

International Journal of Structural Integrity, vol. 13 no. 5
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 8 January 2018

Xiao-dong Yu, Lei Geng, Xiao-jun Zheng, Zi-xuan Wang and Xiao-gang Wu

Rotational speed and load-carrying capacity are two mutual coupling factors which affect high precision and stable operation of a hydrostatic thrust bearing. The purpose of this…

Abstract

Purpose

Rotational speed and load-carrying capacity are two mutual coupling factors which affect high precision and stable operation of a hydrostatic thrust bearing. The purpose of this paper is to study reasonable matching relationship between the rotational speed and the load-carrying capacity.

Design/methodology/approach

A mathematical model of relationship between the rotational speed and the load-carrying capacity of the hydrostatic bearing with double-rectangle recess is set up on the basis of the tribology theory and the lubrication theory, and the load and rotational speed characteristics of an oil film temperature field and a pressure field in the hydrostatic bearing are analyzed, reasonable matching relationship between the rotational speed and the load-carrying capacity is deduced and a verification experiment is conducted.

Findings

By increasing the rotational speed, the oil film temperature increases, the average pressure decreases and the load-carrying capacity decreases. By increasing the load-carrying capacity, the oil film temperature and the average pressure increases and the rotational speed decreases; corresponding certain reasonable matching values are available.

Originality/value

The load-carrying capacity can be increased and the rotational speed improved by means of reducing the friction area of the oil recess by using low-viscosity lubricating oil and adding more oil film clearance; but, the stiffness of the hydrostatic bearing decreases.

Book part
Publication date: 5 August 2015

Tony Kazda and Bob Caves

Abstract

Details

Airport Design and Operation
Type: Book
ISBN: 978-1-78441-869-4

Book part
Publication date: 13 January 2010

Tony Kazda and Bob Caves

Abstract

Details

Airport Design and Operation
Type: Book
ISBN: 978-0-08-054643-8

Article
Publication date: 23 March 2022

Long Liu, Xingpeng Ma, Li Yan and Yongmei Wang

Embedding carbon fiber reinforced plastics (CFRP) bars in the tension zone of reinforced concrete (RC) beams is a widely used reinforcement method, which has the advantages of…

Abstract

Purpose

Embedding carbon fiber reinforced plastics (CFRP) bars in the tension zone of reinforced concrete (RC) beams is a widely used reinforcement method, which has the advantages of strong anti-peel ability and high utilization of tensile materials. To further improve the flexural bearing capacity of RC beams, a new composite reinforcement method using the UHPC layer in the compressive zone of RC beams is proposed based on embedding CFRP bars in the tension zone of RC beams.

Design/methodology/approach

The finite element model of an RC experimental beam with CFRP bars embedded in the tension zone was carried out by ABAQUS. Besides, the reliability of the finite element model results was verified by comparing with the experimental results. On this basis, the flexural reinforcement effect of CFRP bars and UHPC layers on RC beams was analyzed.

Findings

Calculation results show the flexural bearing capacity of the beam strengthened by the new method is 15.9%, which is higher than that of the unreinforced beam, and 10.4% higher than that of the beam strengthened only with CFRP bars. The beam ductility ratio of the new method is 8.25%, which is slightly higher than that of the unreinforced beam and equal to that of the beam reinforced only with CFRP bars embedded in the tension zone. The effectiveness of the new method is further verified by using the analytical calculation method.

Originality/value

A new flexural reinforcement method for reinforced concrete beams is proposed, and the effectiveness of the method was verified by experiments and finite element model. The flexural bearing capacity and ductility of the new method were analyzed based on the load-deflection curve. Finally, the possibility of the new method was verified by analytical analysis.

Details

Multidiscipline Modeling in Materials and Structures, vol. 18 no. 2
Type: Research Article
ISSN: 1573-6105

Keywords

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