一般项目：土石方工程施工(除依法须经批准的项目外，凭营业执照依法自主开展经营活动)。许可项目：各类工程建设活动；房屋建筑和市政基础设施项目工程总承包；施工专业作业(依法须经批准的项目，经相关部门批准后方可开展经营活动，具体经营项目以审批结果为准)。（依法须经批准的项目，经相关部门批准后方可开展经营活动）
Objective It is aimed to tackle the inefficient accuracy of traditional Euler-Bernoulli beam and Winkler foundation model in calculating settlement induced by shield under-passing existing tunnels. Method Based on the Timoshenko beam theory and Pasternak foundation theory, the Timoshenko-Pasternak model, which simultaneously considers the soil shear effect and the tunnel overall shear deformation, is introduced. Settlement control equations for shield under-passing existing tunnels are derived and solved using finite difference method to obtain settlement calculation results. These results are then compared in detail with finite element numerical simulation solutions, actual engineering monitoring data, and theoretical solutions from traditional Euler-Bernoulli-Winkler model. Result & Conclusion Research results show that the Euler-Bernoulli-Winkler model tends to underestimate settlement values and overestimate settlement trough width and segment opening amount for existing tunnels. Additionally, it fails to calculate the segment misalignment amount of existing tunnels. In contrast, the calculation results from Timoshenko-Pasternak model are more consistent with the numerical simulation and actual monitoring values. The model can accurately estimate settlement, settlement trough width, and segment opening amounts for existing tunnels, and provides reliable calculation results for tunnel segment misalignment. The findings are of significant practical value, offering a reliable reference for engineeringapplications.
Due to its novel appearance modeling and good economy, the vase piers are widely used in the bridge construction. The formwork joint leakage accidents caused by the large design error of traditional set-shaped steel formwork are common, which let the concrete surface of pile shaft with honeycomb pockmarked phenomenon. Taking the vase piers of Shenjie No.1 Bridge in Zhengzhou-Fuyang High-speed Railway as the engineering background, the three-dimensional model of pier shaft is built by the software Auto CAD and Revit. The projection method and sheet metal unfolding method are used to solve the complex spatial cambered lofting difficulties.
Taking the self-anchored suspension bridge with two towers and three spans and two cable planes, Weihe Bridge on Union Road as the background, the purpose of this study is to control the errors such as cable force, deflection of main girder and deviation of bridge tower within the scope of construction requirements.The finite element simulation, cyclic tension of sling, and small step and fast running method to push main cable saddle are adopted in the study.The results show that the problem that the sling M9 can not be installed because the limited length of extension rod is solved by adopting the cyclic tension method.At the same time, the main saddle is pushed by combining the small step and fast running method, which optimizes the tension scheme of the sling.In the process of system transformation, through the actual measurement of the deflection of the main girder and the deflection of the bridge tower, it is found that the results of construction control are basically consistent with those of finite element simulation, and the accuracy meets the construction requirements.The research results of this paper could provide reference for similar bridge construction.
