CN-115824536-B - Load test method for different-span loading of continuous beam bridge

CN115824536BCN 115824536 BCN115824536 BCN 115824536BCN-115824536-B

Abstract

The invention relates to the technical field of road and bridge quality detection, in particular to a method for testing load of a continuous beam bridge in different spans, which comprises the following steps of determining a control section on the continuous beam bridge, and measuring the axle weight and the axle base of a test vehicle; calculating and analyzing the area of the section of the effect function of the bending moment along with the change of the moving vehicle; and comparing the ratio of the calculated section area of the effect function of the actually measured bending moment along with the change of the moving vehicle to the section area of the effect function of the actually measured bending moment along with the change of the moving vehicle through a verification coefficient to determine whether the requirement of the bearing capacity is met. The method for testing the load of the different spans of the continuous beam bridge can effectively reduce the arrangement of measuring points and the requirement of test vehicles, and can rapidly and accurately judge the bearing capacity state of the bridge by calculating the effect function of the change of the bending moment along with the moving vehicles and the effect function of the actual measured bending moment along with the change of the moving vehicles.

Inventors

HAO TIANZHI
CHEN QIFENG
YU MENGSHENG
WANG LONGLIN
WANG HUA

Assignees

广西北投交通养护科技集团有限公司
广西交科集团有限公司

Dates

Publication Date: 20260508
Application Date: 20221031

Claims (4)

1. The method for testing the load of the different spans of the continuous beam bridge is characterized by comprising the following steps of: 1) Determining a control section, namely determining a control section on a continuous beam bridge, wherein the continuous beam bridge is a multi-span coupling stressed continuous beam bridge, and a different-span loading mode is adopted, namely a load test mode that a single triaxial test loading vehicle finishes the inter-span continuous loading, the control section is a key section of the continuous beam bridge for different-span coupling stressing, and the position of the control section is arranged in a side span; 2) Measuring the axle weight and the axle distance of the triaxial test loading vehicle; 3) The construction of the effect function of the change of the calculated bending moment along with the moving vehicle comprises the steps of calculating and analyzing the effect function of the change of the calculated bending moment along with the moving vehicle of any section according to the curve of the calculated bending moment influence line of the control section and the axle weight and the axle number of the triaxial test loading vehicle, and calculating and analyzing the interval area of the effect function of the change of the calculated bending moment along with the moving vehicle through integral calculation; The effect function expression of the change of the calculated bending moment of any section along with the change of the moving vehicle is as follows: wherein Xp is the distance from the rear axle of the triaxial test loading vehicle to the origin of the bridge, Calculating a bending moment influence line expression by using any section, wherein X is a coordinate of any section, Z1 is a rear wheelbase, Z2 is a front wheelbase, P1 is a first rear axle weight, P2 is a second rear axle weight, and P3 is a front axle weight; in step 3), the establishment of the calculated bending moment influence line curve of the control section comprises the following steps: B1, measuring the positions of the control sections, wherein each span of the bridge and the total span of the bridge are measured; B2, determining influence line influence factors of each bridge span according to the data obtained in the step B1 and the influence line influence factor expression; b3, calculating a bending moment influence line expression according to the data obtained in the step B2 and any section, and determining a calculated bending moment influence line of the control section; when analyzing the calculated bending moment influence lines of the control section on the corresponding bridge span, determining that the control section is positioned at the position of the corresponding bridge span, and respectively analyzing the calculated bending moment influence lines of the control section on the two ends of the corresponding bridge span; 4) Actual measurement bending moment along with moving vehicle establishment of a change effect function: A1, determining the rigidity of the control section; A2, arranging one or more strain gauges on the control section; A3, driving the triaxial test loading vehicle to open from the bridge head to the bridge tail, analyzing and calculating an actual-measurement bending moment effect function along with the change of the moving vehicle according to the data of the step A1 and the step A2, and calculating the interval area of the actual-measurement bending moment effect function along with the change of the moving vehicle through integral analysis; 5) The method comprises the steps of evaluating the bearing capacity, namely placing the interval area of the effect function of calculating the bending moment along with the change of the moving vehicle and the interval area of the effect function of actually measured bending moment along with the change of the moving vehicle in the same coordinate system, and judging whether the continuous beam bridge meets the requirement of the bearing capacity or not by comparing the interval area of the effect function of calculating the bending moment along with the change of the moving vehicle and the interval area of the effect function of actually measured bending moment along with the change of the moving vehicle; And when the ratio of the area of the section of the effect function of calculating the bending moment along with the change of the moving vehicle to the area of the section of the effect function of calculating the actual bending moment along with the change of the moving vehicle is smaller than 1, the bearing capacity of the bridge meets the requirement, and the ratio is the ratio of the area of the section of the effect function of calculating the bending moment along with the change of the moving vehicle to the area of the section of the effect function of calculating the actual bending moment along with the change of the moving vehicle under the different-span loading scene of the continuous bridge.
2. The method for testing the load of the abnormal span of the continuous beam bridge according to claim 1, wherein in the step A3, the triaxial test loading vehicle is guaranteed to slowly pass through the bridge head to the bridge tail at a constant speed.
3. The method for testing the load of the different spans of the continuous beam bridge according to claim 1, wherein in the step A1, the rigidity of the control section is calculated according to the bridge span length and the concrete grade coefficient analysis.
4. The method for testing the load of the abnormal span of the continuous beam bridge according to claim 1, wherein the strain gauge is used for signal acquisition through a high-speed acquisition device.

Description

Load test method for different-span loading of continuous beam bridge Technical Field The invention relates to the technical field of road and bridge quality detection, in particular to a method for testing load of a continuous beam bridge under different load. Background The bridge is large in China, the newly built and built bridges are numerous, most of the bridges are continuous, some bridges are long in operation, materials are seriously aged, the section rigidity is greatly reduced, and the existing bridge state and the bearing capacity of the old bridge or the new bridge need to be accurately and effectively evaluated. The traditional load test is to calculate the ratio of the internal force or deformation calculated value of the control section under the test load action to the internal force or deformation under the load bearing capacity evaluation load action, so as to obtain the test load efficiency, enable the test load efficiency to be within a certain range, apply the test load on the appointed position of the bridge, measure the static displacement, static strain and other parameters of the test section, and evaluate the working performance and the service capacity of the bridge. The state of the load test can be intuitively evaluated by adopting the traditional load test, and the evaluation result is accurate and reliable. However, the number of vehicles required is large, the number of loading vehicles is large, the time required for load test is long, the whole process needs to be closed, the number of arranged measuring points is large, considerable time and detection cost are consumed, the vehicle is difficult to find in a test site, the loading vehicles cannot weigh to completely meet the calculated load, the vehicle load distribution position is also changed according to different working condition moments, the randomness is too large, and the contrast of repeated test data is not high. And the theoretical data calculated by different software have certain difference, and the actual state cannot be accurately reflected by an algorithm which multiplies the test load according to the influence line points. Disclosure of Invention In order to solve the problems, the invention provides a method for testing the load of the different spans of the continuous beam bridge, which can effectively reduce the arrangement of measuring points and the requirement of test vehicles, and can rapidly and accurately judge the bearing capacity state of the bridge by calculating the effect function of the change of the bending moment along with the moving vehicles and the effect function of the actual measured bending moment along with the change of the moving vehicles. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: The method for testing the load of the different spans of the continuous beam bridge comprises the following steps: 1) Determining a control section on the continuous beam bridge; 2) Measuring the axle weight and the axle base of the test vehicle; 3) The construction of the effect function of the calculated bending moment along with the change of the moving vehicle comprises the steps of calculating and analyzing the effect function of the calculated bending moment along with the change of the moving vehicle of any section according to the calculated bending moment influence line curve of the control section, the axle weight and the axle number of the test vehicle, and calculating and analyzing the interval area of the effect function of the calculated bending moment along with the change of the moving vehicle through integral calculation; The effect function expression of the change of the calculated bending moment of any section along with the change of the moving vehicle is as follows: Wherein Xp is the distance from the rear axle of the test vehicle to the origin of the bridge, is an expression of a bending moment influence line calculated by any section, X is the coordinate of any section, Z1 is the rear wheelbase, Z2 is the rear wheelbase, P1 is the first rear axle weight, P2 is the second rear axle weight, and P3 is the front axle weight; 4) Actual measurement bending moment along with moving vehicle establishment of a change effect function: A1, determining the rigidity of the control section; A2, arranging one or more strain gauges on the control section; A3, driving the test vehicle to open from the bridge head to the bridge tail, analyzing and calculating an actual-measured bending moment effect function along with the change of the moving vehicle according to the data of the step A1 and the step A2, and calculating the interval area of the actual-measured bending moment effect function along with the change of the moving vehicle through integral analysis; 5) And (3) evaluating the bearing capacity, namely placing the interval area of the effect function of calculating the bending moment along with the change of the moving vehicle an