142 results about "Influence line" patented technology

The invention relates to a quick load test method for bridge carrying capacity, and aims to provide a quick and accurate bridge carrying capacity evaluating method. The method comprises the following steps: performing a bridge quasi-static load test; establishing an initial finite element model; correcting the model by a control measuring point strain influence line obtained through actual measurement of the quasi-static load test; respectively distributing loads on the model before and after the correction according to the load test requirement, and calculating to obtain control measuring point flexivity values f before the correction and f after the correction; and defining that eta'=1.1*f after the correction/f before the correction, obtaining a check-calculation coefficient Z2 of a structure according to the efficiency coefficient eta', and performing check calculation on the structure through Z2.

A bridge local damage identification method based on an influence line under a structure health monitoring system relates to the field of engineering structure health monitoring. The method comprises the following steps: (1) fast identification of a bridge influence line; (2) construction of influence line damage indexes; and (3) damage identification based on fusion of multi-sensor information. A bridge influence line is identified based on moving vehicles and bridge response monitored in real time by a bridge health monitoring system, the change of the influence line can be captured in a timelier and quicker way, and structure abnormality can be found early. Based on the fact that the damage indexes of the influence line are more sensitive to local damage of long-span bridges and less sensitive to the change in environmental factors, the method is more applicable to detection of local damage of long-span bridges in an operating environment. By combining the multi-sensor information fusion theory and the influence line damage indexes, the anti-noise-interference and damage locating abilities of the damage identification method are improved greatly, and the credibility of damage decision is improved.

The invention relates to a rapid bridge detection method, which belongs to the technical field of civil engineering application. Firstly, a loading test vehicle with known axle load and wheelbase is adopted for loading to measure response of a test point; then, a method of adopting a specific function (piecewise polynomial and sine wave stacking) to fit the dynamic response of the test point is adopted to extract influence line information of the bridge; a tire-pavement stress distribution emprical formula is introduced to build a tire-pavement contact force trapezoid distribution model; in combination of the actual influence line information and the vehicle tire-pavement contact force distribution model, a linear superposition method is adopted to reconstruct bridge test point response information under different vehicle load combination effects, and thus, rapid bridge detection based on the influence lines is realized. Based on few driving tests on a single vehicle, the actual influence line information can be acquired rapidly and accurately, the bridge response information under different static load combination working conditions is reconstructed, rapid bridge detection is achieved, and the defects that the existing bridge detection method is long in consumed time, high in economic cost and long in traffic block time can be solved.

The invention provides a bridge fast load experimental test method comprising the following steps that a bridge finite element calculation model is established; a displacement measuring point is arranged at the key part of a test span; automobiles are slowly driven along the bridge deck, and the displacement influence line of the bridge is acquired; the actually measured curve of the bridge displacement influence line is drawn; the actually measured displacement value of high credibility is selected according to the actual result of the displacement influence test data; a multi-condition loading model is established according to the selected actually measured displacement value and the vehicle load corresponding position so as to perform finite element analysis and calculation; a displacement residual error expression is established, and a target function is formed to perform finite element model correction; and the deflection and the strain under the load test condition are calculated by adopting the corrected finite element model, the corrected model calculation value acts as the actually measured value and the uncorrected model calculation value acts as the theoretical value to calculate the verification coefficient and bridge carrying capacity evaluation is performed according to the specifications of bridge carrying capacity evaluation.

The invention relates to a bridge bearing capacity evaluation method, and belongs to the technical field of civil engineering application. The method comprises the following steps: firstly, measuringthe dynamic response of a bridge under the action of a moving load through a field test; calculating and extracting an actual influence line of the bridge by adopting a piecewise polynomial function model and a cyclic fitting thought; constructing an influence line evaluation index based on the actual influence line and the theoretical influence line of the bridge; and evaluating the bearing capacity of the bridge by means of the constructed indexes instead of a traditional bridge load test static calibration coefficient. According to the method, the problem of bridge bearing capacity evaluation is solved; a load test method has the defects that the development cost is high, traffic needs to be influenced or interrupted, and time and labor are consumed. The bridge bearing capacity evaluation test process based on the moving load test is simple, the amount of acquired recorded data information is large, and the bridge bearing capacity evaluation test method has great significance in achieving rapidity and economization of bridge bearing capacity evaluation; in addition, the possibility of bridge damage caused by large-scale loading in a static load test can be avoided.

The invention provides a bridge damage detection method. Through field experiments, the bridge bottom testing point flexibility response due to bridge passing by a vehicle can be obtained through test; then, the vehicle axle information is combined; a multi-section function model is introduced; a flexibility influence line (the influence line includes relevant information of the bridge damage) ofthe test point through mathematical inversion; on the basis of the test point position, the base function-non-damaged base function capable of reflecting non-damaged state is built; the damage index is built by combining the flexibility influence line and the non-damaged base function; the damage positioning can be performed through the damage index curve local peak value point. The base functioncapable of describing the damage degree is built according to the recognized damage position information, and is called as the damage base function; the bridge practical flexibility influence line andthe non-damaged base function and the damage base function are built in a combined way; through the least square fitting collation, the effective recognition on the damage degree is realized. The problem of non-damaged state information requirement of the exiting bridge damage detection method is solved. The test is simple; the test data information quantity is great; high practical significanceand values are realized.

The invention relates to a lightning stroke link risk judging method based on thunder and lightning information, which comprises the following steps of: 1, establishing a thunder and lightning statistic buffer zone, and establishing five buffer zones in parallel with a line; 2, counting a ground lightning density of each buffer zone, and counting and sequencing by sections; and 3, forecasting a data flow. According to the lightning stroke link risk judging method based on the thunder and lightning information, on the basis of near real-time data provided by a thunder and lightning locating system, calculation and analysis are carried out according to the condition of ground lightning around the line, then grading is carried out according to the distance between the ground lightning zone and the line and the ground lightning density, and the lightning stroke link risk degree of the influenced line can be given according to the required prediction time.

The invention relates to a method for identifying damage and quantitatively analyzing damage degree of a main girder of a bridge erecting machine. Based on the present situation that the main girder support changes with time in the operation process of the bridge erecting machine, a main girder structure type judging module MI, a damage identifying and analyzing module MII and a damage quantitatively analyzing module MIII are established. The damage identifying and analyzing module includes: (1) a deflection test system is installed; (2) deflection detection data is collected; (3) the detection data is processed to obtain a deflection influence line f1 (x); (4) the deflection influence line is processed to obtain a deflection rate curve f1 "(x); (5) whether mutation exists is judged; (6) the locations and quantity of injuries are judged. The damage quantitatively analyzing module includes: (1) a numerical simulation model is established; (2) n kinds of damage conditions are constructed, and m damage degrees are constructed for each kind of damage condition. (3) the deflection values of different damage degrees are obtained, and the relationship curve of deflection rate and damage degree is defined. (4) the relationship of deflection rate and damage degree of the main girder of the bridge erecting machine is obtained. The invention solves the problem that the structural damage of the main girder of the bridge erecting machine cannot be found in time, and the bridge erecting machine is easy to cause a serious safety accident.

The invention provides a line loss multi-source diagnosis method and system based on correlation analysis. The method comprises following steps of according to acquired basic device information, acquisition information and connection information of a power grid, analyzing key factors influencing line losses so as to obtain a multi-factor clustering analysis result; inputting a multi-data source set, carrying out source end system long link transmission, by use of a preset diagnosis rule, carrying out multi-source connection diagnosis and outing a multi-source connection diagnosis result; setting a line loss rate index abnormal threshold, and using a correlation coefficient method to carry out dynamic diagnosis on wiring and line loss index abnormities in courts; and according to the multi-factor clustering analysis result and the multi-source connection diagnosis result, by combining a physical solid-state factor and a dynamic statistical factor influencing the line losses, carrying out correlation analysis composite diagnosis on the line losses of the power grid. According to the invention, line loss management efficiency of source end service departments of the power grid can beeffectively improved.

The invention discloses a bridge bearing capacity evaluation method based on a field tested influence line. The method is composed of such basic methods as a direct calculation evaluation method, a comparison evaluation method, a finite element model modification evaluation method and the like and mainly comprises the following steps: testing the field tested influence line of a bridge structure if the bearing capacity of the bridge structure can not be obtained by the conventional calculation evaluation method; then on the basis of actually measuring the field tested influence line, evaluating the bridge bearing capacity by the three basic evaluation methods of the method; and further evaluating the bridge bearing capacity with the help of such evaluation methods as load test if the evaluation conclusions can not be made by the three basic evaluation methods. The method has the following advantages: the existing bridge bearing capacity evaluation system is supplemented and perfected; and the method is mainly applied to general survey of the technical conditions of the bridges and evaluation of the bearing capacities of the conventional bridges and can also be applied to evaluation of the bearing capacities of special-shaped bridges, bridges for overweight vehicles to pass temporarily and dangerous bridges.

The invention discloses a method for measuring a bridge influence line in uniform-speed passing of a vehicle. Firstly, according to the passing speed of a tested vehicle and sampling frequency of a sensor, influence line factor points of the tested bridge are determined. Then, dynamic displacement or dynamic strain response is acquired for aiming at the measuring point of the to-be-measured influence line. Finally, a vehicle load matrix is constructed and the bridge influence line is solved. The method settles a problem of incapability of realizing well-posed state in a bridge influence line solving equation, thereby obtaining a more accurate bridge influence line.

The invention discloses a bridge damage detection method based on the strain influence line curvature of an elastic constraint beam. The method comprises the steps of model establishment and analysis,strain influence line analysis and damage identification establishment. According to the invention, boundary conditions with rotation constraint and elastic support are adopted to establish a beam type substructure model with uncertain flexural rigidity and local damage; the analytic expression of the strain influence line of any cross section is deduced; furthermore, the bridge structure damageidentification method based on the difference curvature of the strain influence lines before and after damage is provided, analysis solution proving and numerical example verification prove that the SILC can be used for statically indeterminate bridge damage diagnosis, and theoretical support is provided for application of the SIL method in structure damage diagnosis.

The invention belongs to the technical field of bridge detection, and discloses a bridge load test quick detection system. The system comprises a wireless strain collection system, a wireless deflection collection system, a wireless load vehicle locating system, a base station receiving system and a bridge bearing capacity evaluation system. According to the bridge load test quick detection system disclosed by the invention, the test cost is reduced; only one load vehicle slowly runs on a planned lane; the system records response data of all detection points in real time and associates the response data with moving positions of the load vehicle in real time; influence lines of all the detection points are obtained through actually tested data; loads with different efficiencies are applied based on the influence lines to estimate the bridge bearing capacity.

The invention discloses a beam bridge damage detection method based on a deflection influence line of an elastically restricted supporting beam. The method comprises the following steps: building a model, analyzing a deflection influence line and concretely implementing damage identification. Specific to defects of a fabricated railway bridge model, the method disclosed by the invention builds anelastically supported boundary beam model with a rotation restraint by combining uncertainty of elastic modulus and sectional dimension of a main beam initial material, so as to simulate a main beam structure of a fabricated railway bridge; by deducing an analytic expression of the deflection influence line of the model and combining finite element example analysis, the deflection influence line method is applied to damage identification study on a fabricated beam structure, influence of a position of a measuring point of the influence line, location and level of a local damage as well as testnoise on an identification result is studied, and a method reference and a study thinking are provided for damage identification and service performance evaluation on an existing fabricated railway bridge structure; and the method disclosed by the invention can be used for identifying occurrence of a local damage of an elastically supported beam with a rotation restraint and accurately determining location of the damage and realizes precise damage quantification.

The invention relates to structural mechanics experimental devices, particularly to a bending moment influence line test experimental device of a continuous beam as the statically indeterminate structure. Vertical DOF (degree of freedom) of two ends of a beam is limited by a pair of double-roller supports which are fixed on a stand, and downward DOF of the middle of the beam is limited by a single-roller support, accordingly forming a symmetrical two-span continuous beam structure; moving load is applied on the beam by a roller with a weight hanging, the roller is pulled by a pull line to an optional position of the left span of the beam, strain sensors are symmetrically arranged on the optional positions of the bottom of the beam and connected with a data collecting device, and through a ruler, load acting position and a measuring point are given accurately. According to the arrangement, under moving load action of the continuous beam, bending moment influence lines generated on different positions are quantitatively obtained, and wide application to the structural mechanics experiments of high engineering colleges is achieved.

The invention discloses a determination method of a bridge influence line when a vehicle passes at a non-uniform speed. The determination method of a bridge influence line when a vehicle passes at a non-uniform speed includes the steps: 1) acquiring response vectors of discrete measuring points of a determination influence line as needed; 2) collecting the real-time axle positional information when the vehicle passes a bridge at a non-uniform speed; 3) determining the space between the discrete measuring points of the determination influence line as needed; 4) establishing a position solutionequation of the corresponding set axle every time when collecting response, obtaining the position vector of the corrected set axle, and constructing an axle position matrix; 5) based on the axle position matrix in the step 4), establishing a vehicle load matrix; and 6) based on the response vector and the vehicle load matrix, establishing an equation, and solving the equation to obtain the bridgeinfluence line vector. The determination method of a bridge influence line when a vehicle passes at a non-uniform speed solves the problem that a traditional determination method cannot guarantee that the vehicle can pass the bridge at a uniform speed in the actual test, and solves the ill-posed problem of the bridge influence line solution equation, thus obtaining a more accurate bridge influence line.

The invention discloses a determination method and device of bridge reinforcing target bearing capacity, and relates to the field of safety of bridges. The determination method of bridge reinforcing target bearing capacity comprises the step of measuring the parameters of each car passing through a target bridge within a set time threshold value, the step of processing the parameters to obtain the load effect value when each car passes through the most adverse position of the target bridge, wherein the most adverse position is the position corresponding to the highest point of a load effect influence line corresponding to the target bridge, the step of processing all the load effect values to obtain a sample space satisfying generalized Paratore distribution and further determine a load effect representative value of the target bridge according to the generalized Paratore distribution rule, and the step of obtaining the target bearing capacity of reinforcing the target bridge according to the load effect representative value. The determination method of bridge reinforcing target bearing capacity can accurately deduce bridge load effect extreme values under the condition of a small calculation cost and reinforce the bridge by utilizing the bridge load effect extreme values.

The invention provides a method and a system for establishing a neural network model for determining power grid line loss. The method and the system aim at an optimization problem of line loss modeling input. a mutual information principle method is adopted to identify the intensity degree of main factors influencing line loss; then, based on a training set in a sample set of the collected line loss and influence factors, the influence factors are grouped and sequentially substituted into a training neural network model. The method comprises the steps of determining a plurality of neural network models, determining an evaluation index of each neural network model by utilizing a test set in a sample set, and grouping the evaluation indexes to calculate an evaluation index average value so as to determine an influence factor serving as input of an optimal neural network model, thereby improving the line loss prediction accuracy of the established neural network model.

The invention discloses a uniform-section continuous beam damage identification method for the curvature of a damaged state support counterforce influence line, and the method comprises the steps: applying a moving load to a damaged beam structure, and obtaining a damaged actual measurement support counterforce influence line; solving the curvature of the influence line, and preliminarily judgingthe damage position through the abrupt change of the curvature curve; removing the curvature value of the damaged position, carrying out piecewise linear fitting on the residual curvature curve to obtain an estimated value of the curvature of the support counterforce influence line before damage, subtracting the estimated value from the curvature of the support counterforce influence line after damage, and further judging the damaged position; conducting damage degree quantification according to the relative change of the estimated value of the curvature of the support counter-force influenceline before structural damage and the curvature of the actually-measured support counter-force influence line after damage; and if a new damage position is found, eliminating the influence of damage on the curvature fitting of the reaction influence line of the support before damage, and quantifying the damage degree again. The method can accurately position and quantify the damage of the uniform-section continuous beam, and is applied to damage evaluation of a beam structure.

The invention belongs to the technical field of bridge safety detection, and discloses a bridge influence surface identification method considering vehicle wheel load spatial distribution, which comprises the following steps: 1) loading a bridge with a calibration vehicle by adopting a specific loading path, and collecting response data; 2) numbering the two-dimensional positions of the bridge andestablishing a mathematical model of influence surface identification; and 3) solving the influence surface identification equation by adopting an L2 regularization method. According to the method, actual measurement information of a loading vehicle passing through a bridge of a specific path and bridge response caused by the loading vehicle is utilized, solving is carried out through a bridge two-dimensional position number and a mathematical model established on the basis of the bridge two-dimensional position number, and the influence line recognition precision can be greatly improved; meanwhile, the boundary which cannot be recognized by a traditional method can be effectively reconstructed, and the method has good engineering practical value.

The invention discloses a loading arrangement and adjustment method for a bridge static load test. In combination with a loading shaft weight and vertical marks of influence lines, and through a formula Mk=sigma Fi*Yi, a displacement or internal force calculation value of a test section under the load action of a test car is calculated out; three basic parameters including the number of basic testcars, the coordinates of loading wheel positions and the loading shaft weight Fi are adjusted, so that a ratio of a loading internal force result to a bridge design load internal force result can berapidly obtained, and the ratio is 0.95-1.05; multiple columns of influence line data can be copied to carry out multi-working-condition simultaneous loading calculation; and finally an influence linegraph and a loading graph are drawn. According to the method, an influence line quantity value at any loading wheel position can be quickly obtained; the shaft weight and the coordinates of the loading wheel positions can be quickly changed according to test conditions; and the multi-working-condition loading calculation is carried out simultaneously, so that the loading process of the static load test is greatly simplified, the calculation time is shortened, and the working efficiency of the loading calculation and adjustment of the load test of bridge detection engineers is remarkably improved.