CN-122020809-A - Arch bridge bending moment increase coefficient determination method and system

CN122020809ACN 122020809 ACN122020809 ACN 122020809ACN-122020809-A

Abstract

The invention discloses a method and a system for determining an arch bridge bending moment increase coefficient, and relates to the technical field of arch bridge structural design. The method comprises the steps of obtaining design parameters of an arch bridge, dispersing reasonable arch axes of the arch bridge into a series form, establishing a geometric nonlinear structure response analysis model based on the principle that elastic compression and compressive strain are equal along arc length integral and combining boundary conditions, respectively calculating total bending moment and linear bending moment of the arch bridge under the symmetrical constant load effect through the geometric nonlinear structure response analysis model, calculating initial bending moment increase coefficients based on the total bending moment and the linear bending moment, determining applicable values of the bending moment increase coefficients of different areas based on section position distribution of arch ribs of the arch bridge, and completing determination of the bending moment increase coefficients of the arch bridge. The method and the device have the advantages that the secondary influence of axial force on bending moment is fully considered by dispersing reasonable arch axes and establishing a geometric nonlinear analytical model, the actual bending moment value under the geometric nonlinear effect can be accurately reflected, and the method and the device are suitable for symmetrical constant-load arch bridges with different spans and different sagittal ratios.

Inventors

ZHOU JIANTING
Yue Weiqin
ZHOU YIN
LUO CHAO
XIE XIAOHUA
ZHANG HONG
TANG QIZHI
MEN PENGFEI
CHEN FENGMIN
FAN YONGHUI

Assignees

重庆交通大学
中铁长江交通设计集团有限公司

Dates

Publication Date: 20260512
Application Date: 20260213

Claims (8)

1. The arch bridge bending moment increase coefficient determining method is characterized by comprising the following steps of: Obtaining design parameters of an arch bridge; dispersing a reasonable arch axis of an arch bridge into a series form, and establishing a geometric nonlinear structure response analysis model based on the principle that elastic compression and compressive strain are equal along the integral of the arc length and combining boundary conditions; Respectively calculating the total bending moment and the linear bending moment of the arch bridge under the symmetrical constant load action through the geometric nonlinear structure response analysis model; Calculating an initial bending moment increase coefficient based on the total bending moment and the linear bending moment; And determining the applicable value of the bending moment increase coefficient of different areas based on the distribution of the section positions of the arch bridge arch ribs, and completing the determination of the bending moment increase coefficient of the arch bridge.
2. A method for determining an arch bridge bending moment gain factor as recited in claim 1, wherein the design parameters include span, rise, modulus of elasticity of material, bulk weight, design axis compressive stress, line elastic stability factor, rise-over ratio.
3. The method for determining a bending moment gain factor for an arch bridge according to claim 1, wherein discretizing the reasonable arch axis of the arch bridge into a series form comprises discretizing the reasonable arch axis using a cosine series or a polynomial series.
4. The method for determining an arch bridge moment of increase factor as recited in claim 1, wherein the initial moment of increase factor is a ratio of total moment to linear moment, and the linear moment under the reasonable arch axis is The nonlinear bending moment is Initial bending moment increase coefficient Expressed as: ; Wherein E represents a material elastic die, Represents a horizontal counter-force, Representing the moment of inertia of the dome cross section.
5. The method for determining a bending moment increase coefficient of an arch bridge according to claim 4, wherein the control section of the arch crown section belonging to the bending moment under the symmetrical constant load is obtained by analyzing the nonlinear bending moment When the dome bending moment increase coefficient of the widening dome is obtained, the expression is: 。
6. the method for determining an arch bridge bending moment gain factor according to claim 5, wherein the correction formula of the arch bending moment gain factor of the higher arch under the same parameters is as follows: ; Wherein, the 、 Respectively represent the vault bending moment increase coefficient of the heightened and widened arch, 、、 Respectively represent the antisymmetric first-order stability coefficient of arch rib, the constant load lower shaft compressive stress and span, Is a correction coefficient.
7. A method for determining an arch bridge bending moment gain factor according to claim 1, wherein the correction factor is expressed as follows: 。
8. the arch bridge bending moment increase coefficient determining system is characterized by comprising a parameter acquisition module, a parameter calculation module and a parameter calculation module, wherein the parameter acquisition module is used for acquiring design parameters of an arch bridge; The model construction module is used for dispersing a reasonable arch axis of the arch bridge into a series form, and establishing a geometric nonlinear structural response analysis model based on the principle that elastic compression and compressive strain are equal along the integral of the arc length and combining boundary conditions; The first calculation module is used for calculating the total bending moment and the linear bending moment of the arch bridge under the symmetrical constant load effect through the geometric nonlinear structure response analysis model respectively; the second calculation module is used for calculating an initial bending moment increase coefficient based on the total bending moment and the linear bending moment; and the arch bridge bending moment increase coefficient determining module is used for determining the applicable value of the bending moment increase coefficient of different areas based on the distribution of the section positions of the arch bridge arch ribs and finishing the determination of the arch bridge bending moment increase coefficient.

Description

Arch bridge bending moment increase coefficient determination method and system Technical Field The invention relates to the technical field of arch bridge structural design, in particular to a method and a system for determining an arch bridge bending moment increase coefficient. Background With the continuous increase of bridge span, the problem of ultimate bearing capacity of the arch rib becomes more and more prominent, and more engineering technicians find that the difference between the section bearing capacity and the actual ultimate bearing capacity of the reinforced concrete arch rib calculated by the simplified method of the existing bridge specification of 'equivalent beam column' is larger. Because the true stress mode of the arch bridge is not considered, the value of the bending moment increase coefficient is larger, the true bearing capacity of the large-span arch bridge is seriously underestimated, the designed body quantity of the arch bridge is increased, and the further development of the span of the arch bridge is hindered. Therefore, how to propose an accurate and efficient method for determining the bending moment increase coefficient based on the real bearing mechanism of the large-span arch bridge is a problem to be solved by those skilled in the art. Disclosure of Invention In view of the above, the invention provides a method and a system for determining an arch bridge bending moment increase coefficient, which are based on an arch bridge geometric nonlinear analysis theory and a bearing mechanism, and accurately determine the bending moment increase coefficient in a zoned manner, and consider design precision and efficiency. In order to achieve the purpose, the invention adopts the following technical scheme that the arch bridge bending moment increase coefficient determining method comprises the following steps: Obtaining design parameters of an arch bridge; dispersing a reasonable arch axis of an arch bridge into a series form, and establishing a geometric nonlinear structure response analysis model based on the principle that elastic compression and compressive strain are equal along the integral of the arc length and combining boundary conditions; Respectively calculating the total bending moment and the linear bending moment of the arch bridge under the symmetrical constant load action through the geometric nonlinear structure response analysis model; Calculating an initial bending moment increase coefficient based on the total bending moment and the linear bending moment; And determining the applicable value of the bending moment increase coefficient of different areas based on the distribution of the section positions of the arch bridge arch ribs, and completing the determination of the bending moment increase coefficient of the arch bridge. Preferably, the design parameters include span, sagittal height, material modulus of elasticity, volume weight, design axis compressive stress, line elastic stability coefficient, sagittal ratio. Preferably, the dispersing the reasonable arch axis of the arch bridge into the series form comprises the step of carrying out discrete treatment on the reasonable arch axis by adopting cosine series or polynomial series. Preferably, the initial bending moment increase coefficient is the ratio of the total bending moment to the linear bending moment, and the linear bending moment under the reasonable arch axis isThe nonlinear bending moment isInitial bending moment increase coefficientExpressed as: ; Wherein E represents a material elastic die, Represents a horizontal counter-force,Representing the moment of inertia of the dome cross section. Preferably, the control section of the arch crown section belonging to the bending moment under the symmetrical constant load effect is obtained by analyzing the nonlinear bending moment whenWhen the dome bending moment increase coefficient of the widening dome is obtained, the expression is: 。 Preferably, the correction formula of the vault bending moment increase coefficient of the vault with the same parameters is as follows: ; Wherein, the 、Respectively represent the vault bending moment increase coefficient of the heightened and widened arch,、、Respectively represent the antisymmetric first-order stability coefficient of arch rib, the constant load lower shaft compressive stress and span,Is a correction coefficient. Preferably, the expression of the correction coefficient is as follows: 。 Preferably, an arch bridge bending moment increase coefficient determination system comprises: The parameter acquisition module is used for acquiring design parameters of the arch bridge; The model construction module is used for dispersing a reasonable arch axis of the arch bridge into a series form, and establishing a geometric nonlinear structural response analysis model based on the principle that elastic compression and compressive strain are equal along the integral of the arc length and combining boundary cond