Current Issue : January-March Volume : 2025 Issue Number : 1 Articles : 5 Articles
With the development of science and technology and transportation, high pier and large-span bridges are rapidly rising. Due to the increase in span diameter and pier height, nonlinear and stability problems of bridges become more and more important. In this paper, the stability of large-span steel box-girder suspension bridges is investigated using engineering mechanics methods. Based on the finite element analysis method to solve the bridge structure of the first type of stability problems and the second type of stability problems, the use of the response spectrum method for bridge seismic response. Taking “Xiling Yangtze River Bridge” as the engineering background, the seismic response is analyzed by establishing a finite element model. The axial force of the bridge tower generated by the downstream earthquake is larger than that generated by the transverse earthquake. In the transverse direction, the bending moment MZ is larger than the bending moment MY in the transverse direction, and the bending moment of the pile foundation is larger than the bending moment of the pile foundation in the longitudinal direction. The Xiling Yangtze River Bridge plays a dominant role in transverse seismicity, and its downstream seismic excitation plays a dominant role in longitudinal seismicity. However, the energydemand ratio corresponding to the transverse moment MY is only 1.83, and the strength of the pile section needs to be further improved. For the future innovation of bridge design, a high-performance bridge structure based on UHPC is an important direction for future development....
The visualization method for mechanics knowledge in civil engineering courses is very important, which can help students learn abstract mechanics. Combined with the structural analysis software, this paper develops a visualization teaching approach for mechanical analysis in civil engineering structures based on the proposed deformation decomposition method, such as elastic mechanics, material mechanics and structural dynamics. Compared with traditional strain analysis method, the proposed method is more intuitive and can identify more macroscopic basic deformations. By aid of a survey for undergraduate students and master students, the teaching effectiveness of the visualization course is higher than that of the blackboard writing course. Besides, Mann–Whitney test results show that there is a significant difference. The proportion of undergraduate students that think the combination of visualization has good effects are greater than those of master students. The proposed visualization teaching approach can be promoted in mechanics courses of civil engineering....
Considering the complex construction processes involved, there are significant risks during the construction of long-span cantilever casting arch bridges. In this study, a risk assessment method for the construction process of cantilever casting concrete arch bridges was developed. The compositional elements and characteristics of safety risks in the construction of cantilever casting concrete arch bridges were clarified, and a safety risk source list that includes seven major risk sources and thirty-three minor risk sources was formed. Then, a Bayesian model for the risk analysis of cantilever casting concrete arch bridge construction was established, and a method was proposed to determine the prior and posterior probabilities of the Bayesian network using triangular fuzzy numbers. This method fully utilizes the experience of experts while avoiding the subjectivity of expert opinions. A cantilever casting concrete open spandrel arch bridge (Bridge A) with a total span length of 287 m was taken as an example, and a safety risk assessment was conducted during its construction process. The calculation results show that the construction safety risk level of Bridge A was level III. This engineering application verified the feasibility of determining key node parameters of the Bayesian network using triangular fuzzy numbers....
The “pile–wall” structure, which considers conventional temporary retaining piles as parts of the underground structure in the normal working stage, has been practiced, but there are insufficient studies on the optimization of the design of the “pile–wall” structure and the influence of various factors on the structural stresses and deformations. In order to analyze the factors affecting the stresses and deformations of the “pile–wall” structure, the numerical simulation of the “pile–wall” structure was carried out with the help of finite element simulation software Plaxis 3D through the excavation of Wuhan Optics Valley Center City Distributed Energy Project. The research of stresses and displacements on the “pile–wall” structural under the influence of different factors were carried out. The results show that the number of pile–wall connection nodes, the pile–wall thickness ratio, and the pile–wall stiffness ratio have influences on the stresses and deformations of the “pile–wall” structure. The number of connection nodes which is 4, the pile–wall thickness ratio which is 1 : 0.3, and the pile–wall stiffness ratio which is 1 : 1 are the most reasonable for the deformation and force of pile–wall structure in the project. The research results have good reference and guiding significance for the actual “pile–wall” excavation engineering structure, and the purpose of energy-saving and consumption-reducing construction can be achieved by seeking the reasonable values of the three and optimizing the construction program....
The increase in complexity and quality standards of civil engineering projects continues to drive the innovation of construction materials from the traditional ordinary concrete-steel structure combination to the combination of highperformance concrete and steel structure. In this paper, the application of the combination of high-performance concrete and steel structures in civil engineering projects is investigated based on the mechanical properties of the two structures. The structural reliability index and the corresponding functional function are used to measure the structural reliability of the combination of high-performance concrete and steel structures. After measuring its reliability, a finite element simulation is carried out to investigate the application value of the high-performance concrete-steel structure combination in civil engineering projects. Considering the reliability index of resistance and load time-varying effects decreases with the service time of the combined structure, if the reliability index of the components during the service period is not allowed to be lower than the target reliability index, the time to reach the limit state of the selected high-performance concrete-steel combined building in this paper is about 75 years. The ultimate load-carrying capacity of the highperformance concrete-steel structure combination is increased by 28.74% compared with that of the ordinary concretesteel structure combination, and the end slip of the high-performance concrete-steel structure combination is smaller than that of the ordinary concrete-steel structure combination under the same load. It shows that the advantages of highperformance concrete-steel structures in civil engineering are much more than ordinary concrete-steel structures....
Loading....