Using experimental and numerical analysis, this paper aims at investigating the mechanical behavior in Perfobond rib (PBL) shear connectors with ultrahigh-performance concrete (UHPC)-steel composite structures. Twelve push-out specimens fabricated according to the design used for the connectors in the UHPC-steel composite structures in bridges have been investigated. The main objective of this paper was to discuss the mechanism of failure and the influence of different parameters on PBL shear connectors mechanical properties, including the diameter of transverse rebar, hole spacing and number of holes. The results showed that the failure mode of this type is different from that of conventional concrete specimens. During the failure of specimens, there are few cracks and the overall stiffness still maintain a high level, and reveal that a balance between the size of transverse rebar and the diameter of the hole. In addition, the basic form of the ultimate bearing capacity of existing PBL shearing bonds is summarized, and a new concept of steel fiber shearing in UHPC is proposed. Finally, based on the elastic foundation beam model, the full curve calculation formula of UHPC single-hole PBL shear bond is derived by using Timoshenko beam element. The formula calculation results are in good agreement with the experimental values.

As the core course of civil engineering, the teaching quality of bridge engineering and the learning effectiveness of students are crucial for the construction of bridge engineering. The traditional teaching of bridge engineering courses tends to be teacher-centered, with learning as a supplement, and therefore is commonly referred to as teacher-centered. This article analyzes the drawbacks of the teacher-centered teaching model and proposes a student-centered holographic teaching method in the teaching practice of bridge engineering courses. By reconstructing the learning content and constructing a holographic information field from a comprehensive perspective of digital, physical, and humanistic aspects, a teacher–student learning community guided by teachers and deeply participated in by students is established. From the perspective of integrating life experience, professional knowledge cognition, and engineering philosophy thinking, the learning effect of students is made high order, innovative, and challenging. The improved analytic hierarchy process (AHP) was used to evaluate the student-centered holographic teaching concept, and the results showed that adopting a multidimensional and multi-level holographic teaching method has great practical significance in promoting the establishment of student knowledge systems and the development of diversity.

The existing safety analysis methods for the assessment of the aerostatic stability of long-span symmetry cable-stayed bridges have difficulties in meeting the requirements of engineering applications. Based on the finite element method and the inverse reliability theory, an approach for the probabilistic safety analysis of the aerostatic instability of long-span symmetry cable-stayed bridges is proposed here. The probabilistic safety factor of aerostatic instability of long-span symmetry cable-stayed bridges was estimated using the proposed method, with Sutong Bridge as an example. The probabilistic safety factors for the aerostatic instability of Sutong Bridge were calculated using the finite element inverse reliability method, based on the FORM approach. The influences of the mean value and the coefficient of variation of random variables, as well as the iterative step length of finite difference, on the probabilistic safety factors of aerostatic instability of Sutong Bridge were analyzed. The results indicated that it is necessary to consider the uncertainties of random variables in probabilistic safety factor assessments of aerostatic instability in cable-stayed bridges using the proposed method, which could be recommended for the assessment of safety factors involved in the aerostatic instability of long-span symmetry cable-stayed bridges. The randomness of the parameters had an important influence on the probabilistic safety factor of the aerostatic stability of Sutong Bridge. Neglecting the randomness of these parameters may result in instability of the structure.

In order to improve the estimation accuracy of bearing capacity of pile foundation, a new forecast method of bearing capacity of pile foundation was proposed on Jeffrey’s noninformative prior using the MCMC (Markov chain Monte Carlo) method of the Bayesian theory. The proposed approach was used to estimate the parameters of Normal distribution. Numerical simulation was used to produce pseudosamples. The parameter estimation of the maximum likelihood method and the Bayesian statistical theory was used to estimate the parameter estimation of the Normal distribution, which has been compared with the theoretical value of the pseudosample of Normal distribution. The result indicates that the forecast model of Normal distribution using the Bayesian method is better than that of the maximum likelihood method, and the performance of the proposed method was improved with increasing of pseudosample number. At last, the proposed method was applied to estimate the parameter of Normal bearing capacity distribution of pile foundation, which shows that the proposed method has a high precision and good applicability.

Most existing methods for the determination of the reasonable finished state of self-anchored symmetry suspension bridges were based on the stress state of the stiffening girders used in the construction. A simple and practical control method for the reasonable completion state of stiffened beam based on double control indexes of deformation and stress was proposed. In this paper, the long-term effects of shrinkage and creep were taken into consideration, and a finite element model was built to study the change in the stiffening girder stress during operation. The mid-span deflection of the middle span sustained increasing and the compression stress in the bottom slab of the stiffening girder consistently decreased under the effects of shrinkage and creep. The speed changes from fast to slow and tends to become stable in 50 years. Furthermore, stiffening girders under the action of hanger force, dead weight, cable force, and pre-stress were investigated to study the mechanism of the stress change during operation. Based on the safety stress state of stiffening girders after 50 years, a new control method for the reasonable finished state was proposed. Moreover, the total cross-section of stiffening girders maintained the compression stress state during the developing processes of shrinkage and creep in 50 years. Finally, the utilization in the Hunan Road self-anchored symmetry suspension bridge verified the simplicity and practicality of this new control method and confirms that the method can be implemented to guide the design and construction of the similar bridges.

A new structure termed “concrete-filled FRP-grooved steel composite tube (CFGCT) column” is proposed, which is composed of a stress-released steel tube (i.e., grooved steel tube), fiber-reinforced polymer (FRP) and concrete. Axial load tests were carried out on twenty-four specimens to investigate the constraint effect of this structure. Three main experimental variables were considered: the steel tube thickness, the FRP type, and the FRP layer. The failure modes, stress-strain relationships and the effect of the main experimental variables were discussed. The stress-strain curves of this new structure are composed of an initial linear part, a nonlinear transition part, a strengthening part and a residual part. The test results demonstrate that the bearing capacity of the structure was improved, and that the mechanical mechanism of the structure was simplified due to the stress-released grooves. Based on the test results and previous studies, formulas for calculating the ultimate stress (f_cu), ultimate strain (ε_cu), peak stress (f_cc) and peak strain (ε_cc) were proposed. In addition, models for predicting the stress-strain curves of CFGCT columns were put forward, and the models could precisely simulate the stress-strain curve of this new composite structure. Hence, this study indicates that a structure composed of FRP and stress-released steel tube can effectively constrain concrete.