No abstract

In view of the fact that the anti sliding effect analysis of the current anchor cable and anti slide pile structure is not yet complete, research on the synergy mechanism of adjacent pile-anchor composite structures under traffic load is carried out. Firstly, a free vibration analysis for the slope dynamic model is carried out by using a three-dimensional finite element numerical simulation method. By improving the slope boundary conditions of time-domain analysis, the time-domain equation of the dynamic model of traffic load acting on the top of the slope is solved accurately, and the response law of the internal force of the pile anchor composite structure is also described. The mechanism by which the pile anchor composite structure resists against the slope sliding through the internal force increment is proposed: this internal force increment is estimated to be 73.4%, while that of anchor cable is 26.6%. The composite structure presents the coordinated sharing for sliding force. The internal force of the lower row of anchor cables is 89.48 kN larger than that of the upper row, and the internal force increment is four times larger, indicating that the lower anchor cable is more effective in slope reinforcement. As the deformation at the top of the slope is greater, the prestress of the upper anchor cable should be increased to avoid the “chain failure” caused by excessive deformation. As a result, the coordination law of internal force of pile anchor is revealed, and the anti sliding sharing mechanism is clarified. A design idea of the adjacent pile-anchor composite structure is proposed, which takes 0.2‐0.3 times the remaining sliding force as the design value of prestressed anchor cable. The idea fully considers the anti sliding effect of prestressed anchor cables and reduces the design size of anti slide pile section, providing a theoretical support for optimization design of combined anti slide structure and saving project investment.

For long-span steel bridges, the contact states between the pavement and the steel decks change significantly during the operation stage. Different interlayer contact states have different effects on the viscoelastic mechanical properties of the pavement. Here, the modified SMA10 mixture and the epoxy–asphalt mixture are compared in terms of the transverse tensile strain, the transverse tensile stress, and the deflection at the bottom of the asphalt layer under different contact conditions. The main curve clusters of the relaxation modulus were obtained using the creep test data, and the effects of four different contact conditions on the viscoelastic mechanical response of the asphalt mixture pavement of the Huangpu Suspension Bridge in China were analyzed accordingly. It was found that the delayed deformation capacity of the epoxy–asphalt mixture is better than that of the modified SMA10 mixture. The change of the interlayer contact condition has an impact on the viscoelastic mechanical response of the asphalt mixture pavement; for the modified SMA10 asphalt mixture pavement, the transverse tensile stress and the transverse tensile strain at the bottom of the pavement are more sensitive to the contact condition than the deflection. For the epoxy–asphalt mixture pavement, the deflection is more sensitive to the contact condition.

For laminated beams connected by Coulomb friction, interlayer slippage occurs when interfacial shear stress exceeds the resistant friction stress. Then, the physical properties of the laminated beams will change and may even cause structural damage. In this article, the law of interlayer slippage of laminated beams is obtained by mechanical derivation, and the finite element model is used for comparison verification. First, the internal shear force calculation formula of the laminated beam considering the interlaminar friction is derived from the segment micro-element method. Second, interlayer slippage laws of the frictional laminated beams in both horizontal and longitudinal direction are derived according to the hierarchical slip determination conditions. Third, according to the state quantity of different boundary conditions, the transfer matrix method is used to solve the longitudinal length of interlayer slip. Then, the design of the algorithm program is completed by MATLAB. Finally, based on the comparison between the finite element model calculation results and the calculation results of the algorithm program, the accuracy of the proposed method is verified. The analysis results indicate that slippage destroys the integrity of the laminated beam section and reduces the bending moment of inertia of the slip section of the beam. The influence of slip effect on the frictional laminated beams should be considered in deflection calculation.

In the bridge engineering, there are some problems about the dynamics that traditional theory cannot solve. So, the theory about stress waves is introduced to solve the related problems. This is a new attempt that the mechanic theory is applied to practical engineering. The stress wave at a junction of the structure composed of beams and strings is investigated in this paper. The structure is studied because the existence of a soft rope makes the transmission of the force in the bridge structure different from the traditional theory, and it is the basis for further research. The equilibrium equations of the displacement and the internal force are built based on the hypothesis. The fast Fourier transform (FFT) numerical algorithm is used to express an incident pulse of arbitrary shape. The analytical solutions are substantiated by comparing with the finite element programs. The conclusion that if the cross section of the string is relatively small, then the energy density of the structure is relatively large, which is disadvantageous to the structure, can be obtained from this paper.