CN-116105951-B - Method for rapidly evaluating bearing capacity of continuous beam based on area of influence line of bending moment of arbitrary section

CN116105951BCN 116105951 BCN116105951 BCN 116105951BCN-116105951-B

Abstract

The invention belongs to the technical field of bridge and culvert engineering quality detection in the transportation industry. A method for quickly evaluating the bearing capacity of continuous beam based on the influence line area of bending moment of optional cross section includes such steps as using the vehicles with known axle weights, axle bases and axle numbers as loading vehicles, setting the weights P 1 and P 2 of rear axle I and the weights P 3 of rear axle II and III, and building the effect function of bending moment at optional cross section x along with the change of moving vehicles Finally to And under the same condition, testing the integral value of the effect function of the bending moment at the section x along with the change of the moving vehicle as a numerator, wherein the integral value of the effect function is used as a denominator in the maximum peak value interval of n times, n is 0-1, and the ratio of the numerator to the denominator is smaller than 1, so that the bridge bearing capacity meets the requirement. The invention can improve the detection precision and efficiency of the existing bridge load and reduce the cost of manpower and material resources.

Inventors

HAO TIANZHI
CHEN QIFENG
YU MENGSHENG
WANG LONGLIN
YANG YUHOU

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 (1)

1. The method for rapidly evaluating the continuous beam bearing capacity based on the area of the bending moment influence line of any section is characterized in that when the bridge influence line is the bending moment influence line of any section x of the bridge, the method for evaluating the continuous beam bearing capacity comprises the following steps: (1) A vehicle with known axle weight, axle base and axle number is used as a loading vehicle, the weight P 1 of a rear axle I of the loading vehicle, the weight P 2 of a rear axle II and the weight P 3 of a rear axle III are set; (2) Constructing a bending moment variation effect function of any section x along with the moving vehicle; The bridge can be divided into two ends of a bridge head and a bridge tail, the bridge head is selected as an origin, the bridge head is an upper bridge end of a loading vehicle, the loading vehicle passes through the bridge from the bridge head at a constant speed, the strain value of any section x is collected, and the bending moment of any section x along with the change effect function expression of the moving vehicle is obtained by performing inverse calculation on the actual rigidity of the measured strain value and the control section on site: in the formula, The effect function of the bending moment at any section x along with the change of the moving vehicle is as follows; for the bending moment influence line expression at any section X, Z 1 is the rear wheelbase, Z 2 is the front wheelbase, and X p is the distance from the rear axle of the loading vehicle to the origin; (3) For a pair of Under the same condition, testing the bending moment at the section x along with the change of the moving vehicle, wherein the bending moment is used as a numerator, and the ratio of the numerator to the denominator is smaller than 1, so that the bridge bearing capacity meets the requirement; the continuous beam is a three-span continuous beam with any cross section and any span, and comprises a bridge 1# span, a bridge 2# span and a bridge 3# span; In the step (2), defining a 1# span of the continuous beam as L 1 , a 2# span as L 2 and a 3# span as L 3 , wherein the 1# span influence line influence factors are a 1 、a 2 , the 2# span influence line influence factors are b 1 、b 2 and the 3# span influence line influence factors are c 1 、c 2 respectively, and the bending moment influence line expression at any section x is ②、③、④: : , : ,③ : ,④ Wherein L is the total span of the three-span continuous beam The influence line influence factors are respectively as follows: , , , , , , in the formula, , ⑤ , ⑥ , ⑦ , ⑧ ⑨ 。

Description

Method for rapidly evaluating bearing capacity of continuous beam based on area of influence line of bending moment of arbitrary section Technical Field The invention belongs to the technical field of bridge and culvert engineering quality detection in the transportation industry, and particularly relates to a method for rapidly evaluating the bearing capacity of a continuous beam based on the area of an influence line of bending moment of any section. Background The method is characterized in that the method is used for evaluating the state of the existing bridge and determining the bearing capacity of the bridge, the state of the bridge can be intuitively evaluated by using a load test, the evaluation result is more accurate and reliable, but the problem of long time required by the load test exists, the whole test process needs to be closed, the number of the arranged measuring points is large, considerable time and detection cost are required, the actual detection result is usually compared with the analysis of a structural model, the theoretical data are calculated by different software to a certain extent, and the actual state cannot be accurately reflected according to the algorithm of influencing the load of the line point multiplication test. The traditional load test is to calculate the test load efficiency under the test load effect within a certain range, apply the test load on the appointed position of the bridge, and measure the static displacement, static strain and other parameters of the test section, so as to evaluate the working performance and the service capacity of the bridge. The traditional method needs more vehicles, the vehicle finding is difficult in a test site, the load of the loaded vehicle cannot completely meet the calculated load, the vehicle load distribution position is changed at different working conditions, the randomness is too high, and the repeated test data has low contrast. Therefore, how to solve the above problems in actual detection and calculation is an important technical problem to be solved. Disclosure of Invention The invention overcomes the defects of the technical problems, provides the method for rapidly evaluating the bearing capacity of the continuous beam based on the influence of any section bending moment on the line area, can improve the detection precision and efficiency of the existing bridge load, and reduces the cost of manpower and material resources. In order to solve the technical problems, the invention adopts the following technical scheme: 1. The method for rapidly evaluating the bearing capacity of the continuous beam based on the area of the bending moment influence line of any section comprises the following steps of: (1) A vehicle with known axle weight, axle base and axle number is used as a loading vehicle, the weight P 1 of a rear axle I of the loading vehicle, the weight P 2 of a rear axle II and the weight P 3 of a rear axle III are set; (2) Construction of moment-to-moment effect function of any section x along with change of moving vehicle The bridge can be divided into two ends of a bridge head and a bridge tail, the bridge head is selected as an origin, the bridge head is an upper bridge end of a loading vehicle, the loading vehicle passes through the bridge from the bridge head at a constant speed, the strain value of any section x is collected, and the bending moment of any section x along with the change effect function expression of the moving vehicle is obtained by performing inverse calculation on the actual rigidity of the measured strain value and the control section on site: in the formula, The effect function of the bending moment at any section x along with the change of the moving vehicle is as follows; For the bending moment influence line expression at any section X, Z 1 is the rear wheelbase, Z 2 is the front wheelbase, and X p is the distance from the rear axle of the loading vehicle to the origin; (3) For a pair of And under the same condition, testing the integral value of the effect function of the bending moment at the section x along with the change of the moving vehicle as a numerator, wherein the integral value of the effect function is used as a denominator in the maximum peak value interval of n times, n is 0-1, and the ratio of the numerator to the denominator is smaller than 1, so that the bridge bearing capacity meets the requirement. Further, the continuous beam is a three-span arbitrary-section arbitrary-span continuous beam, and the continuous beam comprises a bridge No. 1 span, a bridge No. 2 span and a bridge No. 3 span. Further, in the step (2), defining a 1# span of the continuous beam as L 1, a 2# span as L 2, a 3# span as L 3, a 1# span influence line influence factor as a 1、a2, a 2# span influence line influence factor as b 1、b2, and a 3# span influence line influence factor as c 1、c2, wherein the bending moment influence line expression at any section x is ②、③、④: Wherein, L is the total