Wage Structure Determinants and Gender Pay Gap among Wage Earners: from Mean to Overall Log Wage Distributional Decomposition

HongYe Sun,GiSeung Kim 서울대학교 경제연구소 2017 Seoul journal of economics Vol.30 No.1

This study comprehensively investigates the wage structure determinants and gender pay gap in Korea. Using 2014 Korean Labor and Income Panel Study (KLIPS) data, we find that individual characteristics exhibit significant differences across the distribution and that magnitude and significance differ according to gender. Findings suggest that returns to education are high for women and experience is influential only for women at the upper wage distribution. By applying vigorous counterfactual decomposition method, we find large returns on characteristic differentials by gender, especially for lowly educated women. A strong glass ceiling effect in Korea is obtained, and the integrative effect is composed of the continuously increasing composition effect and N-shaped (i.e., low at both ends) structure effect. In particular, most of the explained differentials are attributable to the differences of experience. The high returns on education for women are beneficial for reducing discrimination (unexplained or structure effect).

Effect of bridge lateral deformation on track geometry of high-speed railway

Hongye Gou,Longcheng Yang,Dan Leng,Yi Bao,Qianhui Pu 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.29 No.2

This paper presents an analytical model to analyze the mapping relationship between bridge lateral deformation and track geometry of high-speed railway. Based on the rail deformation mechanisms, the deformation of track slab and rail at the locations of fasteners are analyzed. Formulae of rail lateral deformation are derived and validated against a finite element model. Based on the analytical model, a rail deformation extension coefficient is presented, and effects of different lateral deformations on track geometry are evaluated. Parametric studies are conducted to evaluate the effects of the deformation amplitude, fastener stiffness and mortar layer stiffness on the rail deformation. The rail deformation increases with the deformation of the girder, and is dependent on the spacing of the fasteners, the elastic modulus of the rail's material, and the moment of inertia of the rail's section.

Static and dynamic responses of a tied-arch railway bridge under train load

Hongye Gou,Biao Yang,Wei Guo,Yi Bao 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.71 No.1

In this paper, the static and dynamic responses of a tied-arch railway bridge under train load were studied through field tests. The deflection and stresses of the bridge were measured in different static loading scenarios. The dynamic load test of the bridge was carried out under the excitation of running train at different speeds. The dynamic properties of the bridge were investigated in terms of the free vibration characteristics, dynamic coefficients, accelerations, displacements and derailment coefficients. The results indicate that the tie of the measuring point has a significant effect on the vertical movement of the test section. The dynamic responses of arch bridge are insensitive to the number of trains. The derailment coefficients of locomotive and carriage increase with the train speed and symmetrically distributed double-line loads reduce the train derailment probability.

Mapping vertical bridge deformations to track geometry for high-speed railway

Hongye Gou,Zhiwen Ran,Longcheng Yang,Yi Bao,Qianhui Pu 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.32 No.4

Running safety and ride comfort of high speed railway largely depend on the track geometry that is dependent on the bridge deformation. This study presents a theoretical study on mapping the bridge vertical deformations to the change of track geometry. Analytical formulae are derived through the theoretical analysis to quantify the track geometry change, and validated against the finite element analysis and experimental data. Based on the theoretical formulae, parametric studies are conducted to evaluate the effects of key parameters on the track geometry of a high speed railway. The results show that the derived formulae provide reasonable prediction of the track geometry change under various bridge vertical deformations. The rail deflection increases with the magnitude of bridge pier settlement and vertical girder fault. Increasing the stiffness of the fasteners or mortar layer tends to cause a steep rail deformation curve, which is undesired for the running safety and ride comfort of high-speed railway.

Flexural behaviors of full-scale prestressed high-performance concrete box girders

Hongye Gou,Jie Gu,Zhiwen Ran,Yi Bao,Qianhui Pu 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.75 No.5

In this study, the flexural behaviors of full-scale prestressed concrete box girders are experimentally investigated. Four girders were fabricated using two types of concrete (compressive strengths: 50 MPa and 70 MPa) and tested under four-point bending until failure. The measured parameters included the deflection, the stress and strain in concrete and steel bars, and cracks in concrete. The measurement results were used to analyze the failure mode, load-bearing capacity, and deformability of each girder. A finite element model is established to simulate the flexural behaviors of the girders. The results show that the use of high-performance concrete and reasonable combination of prestressed tendons could improve the mechanical performance of the box girders, in terms of the crack resistance, load-carrying capacity, stress distribution, and ductility.

In-situ dynamic loading test of a hybrid continuous arch bridge

Hongye Gou,Liang Li,Yu Hong,Yi Bao,Qianhui Pu 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.77 No.6

In this study, the dynamic behavior of a three-span hybrid continuous arch bridge under vehicle loading is investigated. The natural vibration characteristics of the bridge were analyzed through pulsation test. In the dynamic loading test, the vibrations of the bridge under different truck speeds and different pavement conditions were tested, and time histories of deflection and acceleration of the bridge were measured. Based on the dynamic loading test, the impact coefficient was analyzed. The results indicate that the pavement smoothness had more impacts on the vibration of the bridge than the truck’s speed. The vertical damping of the bridge under the excitation of the trucks is larger than the transverse damping. Resonance occurs at the side span of the bridge under a truck at 10 km/h.

Running safety of high-speed train on deformed railway bridges with interlayer connection failure

Hongye Gou,Chang Liu,Rui Xie,Yi Bao,Lixiang Zhao,Qianhui Pu 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.39 No.3

In a railway bridge, the CRTS II slab ballastless track is subjected to interlayer connection failures, such as void under slab, mortar debonding, and fastener fracture. This study investigates the influences of interlayer connection failure on the safe operation of high-speed trains. First, a train-track-bridge coupled vibration model and a bridge-track deformation model are established to study the running safety of a train passing a deformed bridge with interlayer connection failure. For each type of the interlayer connection failure, the effects of the failure locations and ranges on the track irregularity are studied using the deformation model. Under additional bridge deformation, the effects of interlayer connection failure on the dynamic responses of the train are investigated by using the track irregularity as the excitation to the vibration model. Finally, parametric studies are conducted to determine the thresholds of additional bridge deformations considering interlayer connection failure. Results show that the interlayer connection failure significantly affects the running safety of high-speed train and must be considered in determining the safety thresholds of additional bridge deformation in the asset management of high-speed railway bridges.

Effect of track defects on track deformations for high-speed railway bridge

Hongye Gou,Rui Xie,Chang Liu,Wei Guo,Bing Han,Yi Bao 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.41 No.3

Track defects can change the interaction between layers and affect the nonlinear contact between the beam and base slab, causing deformations in the rail. This study proposes a theoretical model to clarify the influence mechanism of track defects on the track irregularity of high-speed railway bridges under pier settlement. The investigated track defects include the void under slab, interlayer debonding, and fastener fracture. The elongation coefficient of track deformation is used to describe the mapping characteristics of the interlayer parameters to track geometric under the additional bridge deformation. The geometric characteristics and changing trend of the rail surface are quantified under the influence of the failure position and critical length. Finally, the fundamental mechanisms of track deformation are elucidated, which lays a theoretical basis for further study of the long-term evolution of infrastructure.

Behavior of steel-concrete composite cable anchorage system

Hongye Gou,Wei Wang,Xiaoyu Shi,Qianhui Pu,Rui Kang 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.26 No.1

Steel-concrete composite structure is widely applied to bridge engineering due to their outstanding mechanical properties and economic benefit. This paper studied a new type of steel-concrete composite anchorage system for a self-anchored suspension bridge and focused on the mechanical behavior and force transferring mechanism. A model with a scale of 1/2.5 was prepared and tested in ten loading cases in the laboratory, and their detailed stress distributions were measured. Meanwhile, a three-dimensional finite element model was established to understand the stress distributions and validated against the experimental measurement data. From the results of this study, a complicated stress distribution of the steel anchorage box with low stress level was observed. In addition, no damage and cracking was observed at the concrete surrounding this steel box. It can be concluded that the composite effect between the concrete surrounding the steel anchorage box and this steel box can be successfully developed. Consequently, the steel-concrete composite anchorage system illustrated an excellent mechanical response and high reliability.

Spatial mechanical behaviors of long-span V-shape rigid frame composite arch bridges

Hongye Gou,Qianhui Pu,Junming Wang,Zeyu Chen,Shiqiang Qin 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.47 No.1

The Xiaolan channel super large bridge is unique in style and with greatest span in the world with a total length of 7686.57 m. The main bridge with spans arranged as 100m+220m+100m is a combined structure composed of prestressed concrete V-shape rigid frame and concrete-filled steel tubular flexible arch. First of all, the author compiles APDL command flow program by using the unit birth-death technique and establishes simulation calculation model in the whole construction process. The creep characteristics of concrete are also taken into account. The force ratio of the suspender, arch and beam is discussed. The authors conduct studies on the three-plate webs’s rule of shear stress distribution, the box girder’s longitudinal bending normal stress on every construction stage, meanwhile the distribution law of longitudinal bending normal stress and transverse bending normal stress of completed bridge’s box girder. Results show that, as a new combined bridge, it is featured by: Girder and arch resist forces together; Moment effects of the structure are mainly presented as compressed arch and tensioned girder; The bridge type brings the girder and arch on resisting forces into full play; Great in vertical stiffness and slender in appearance.