A Judgment Method for the Range of Coupling Effects of High-Speed ​​Railway Track Constraints

Abstract

The invention discloses a method for judging the range of coupling effects of high-speed railway track constraints, which includes the following steps: (1) distinguishing the key research part and the non-key research part of the CRTSII high-speed railway simply supported beam bridge model, and classifying according to the degree of importance of the research (2) Study the coupling effect of the subsequent structure on the target structure, transform the subsequent structure into the equivalent boundary of the target structure, and then establish a simplified calculation model; (3) Use the sensitivity calculation formula to describe the subsequent structure The impact on the target structure, and judge the subgrade and subsequent bridges within the coupling range through the sensitivity critical point. The judging method of the present invention can more accurately analyze the dynamic response of simply supported beam bridges on high-speed railways under earthquake action, can improve the scientific research efficiency of high-speed railway-related dynamic response research considering track constraints, and has important theoretical significance and engineering application value.

Description

technical field [0001] The invention belongs to the field of civil engineering, and in particular relates to a method for judging the coupling effect range of a high-speed railway track constraint. Background technique [0002] In the design of high-speed railway track structures, seamless lines have obvious advantages in terms of technology, safety and economy compared with traditional seamed lines, so seamless lines have been widely used in high-speed railway structures. In the previous studies on the seismic response of large-span high-speed railway bridges with seamless lines, only typical structures or special sections or several-span bridges with special structures were taken for analysis, and the constraints of the track were simplified or even ignored. influences. In traditional bridges with seamed lines, the steel rails are discontinuous, and the beam-rail interaction is small, and the impact of track constraints on the seismic resistance of the bridge is small, or...

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Problems solved by technology

In traditional bridges with seamed lines, the steel rails are discontinuous, and the beam-rail interaction is small, and the impact of track constraints on the seismic resistance of the bridge is small, or even negligible; however, the typical seamless track of the CRTSII track slab Certain longitudinal constraints are provided to enhance the coupling between bridges, so that the seismic response of any part of the bridge will be affected by other bridge spans. If these factors are completely ignored during the model building process, the seismic response results of the bridge may be different from the real ones. the situation is very different

[0003] At present, in the seismic response research of CRTSII high-speed railway simply supported girder bridge, the track constraint processing method at the boundary of the calculation model needs to be improved. The two track processing methods used in the conventional calculation model have certain shortcomings: 1) The spring system is used In most studies of the equivalent orbital constraint, the value of the spring stiffness and mass is often subjective, and there is no complete derivation process, and the method with the derivation process also has certain limitations, and it is difficult to guarantee the accuracy of the seismic response of the simplified calculation model; in addition, An overly simple spring system is also difficult to simulate the complex interlayer relationship in the track system under earthquake; 2) The modeling method of extending the track system to the subgrade can better simulate the longitudinal constraint effect of the subgrade track, but for several It is not feasible to calculate the simply supported girder bridge of a high-speed railway with a span of several kilometers or even tens of kilometers by taking the whole bridge structure, so it is difficult to include the subgrade at both ends of the bridge in the calculation model; in addition, scholars who adopt this approach have not proposed Clear indicators to judge the appropriate subgrade length

In the past studies, there was little research on the scope of the coupling effect, and a suitable calculation method and index for the scope were not proposed, which led to two problems: 1) It is impossible to quickly judge the subgrade section connected to the bridge through the track system Reasonable length; 2) It is impossible to quickly judge the coupling effect range of the seismic response of a specific part of a simply supported beam bridge of any large-span high-speed railway

Both of these issues can have a profound impact on computational accuracy and research efficiency

In past studies, it was often necessary to establish a series of complete models (different numbers of spans, different subgrade lengths) for seismic response trial calculations to determine the range of coupling effects, which greatly affected the overall research efficiency.

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