Short-term monitoring and bearing capacity evaluation method for existing bridges

Abstract

The invention discloses a short-term monitoring and bearing capacity evaluation method for existing bridges, and belongs to the technical field of highway engineering detection. The method comprises determining a loaded verification coefficient by a quasi-static equivalent load test; determining the static dynamic characteristics of a bridge by a dynamic equivalent load test and an operation loadtest, wherein the quasi-static equivalent load test includes the determination of a test type, the determination of an equivalent vehicle and the installation and commissioning process of a sensor; performing the equivalent load test and the operation load test; performing data acquisition and data processing. The method provided by the invention has less investment in practical application, but has high technical added value; has little impact on traffic, can achieve monitoring and evaluation without traffic interruption, and has a large amount of data that can be processed, complete information, and high evaluation accuracy.

Description

technical field [0001] The invention relates to the technical field of bridge monitoring, in particular to a method for short-term monitoring and bearing capacity evaluation of existing bridges. Background technique [0002] At present, the evaluation of the bearing capacity of highway operating bridges mainly adopts two technical methods: load test and health monitoring: the load test is low in cost, the result is intuitive, and has high reliability, which is easy to be accepted by the highway management and maintenance department; the health monitoring technology is high, and the test technology is gradually mature. But the cost is high, and the evaluation conclusion is controversial. The development of load test has gone through 30 years: In 1988, the former Ministry of Communications issued the "Method for Appraisal of Bearing Capacity of Old Highway Bridges"; ". The development of health monitoring has gone through 15 years: around 2000, sensor systems were gradually ...

AI Technical Summary

Problems solved by technology

[0004] (1) The amount of test information is relatively small, and the assessment of the bearing capacity of the bridge is too arbitrary. Sometimes the test results of bridges with many problems are also very good!

[0005] (2) The loading time is too long. Under normal circumstances, it takes about 1 hour for static loading of a section, and 3-4 hours for a bridge including dynamic loading. Important roads cannot bear the pain of traffic interruption

[0006] (3) Only live loads are equivalently loaded, and other variable loads such as temperature and wind cannot test the effect

[0007] (4) The actual traffic volume cannot be measured, so the evaluation conclusion cannot be given according to the actual operation situation

[0008] (5) The preparation time for sensor installation and bridge calculation is long, but the test time is relatively short and the efficiency is very low

[0012] (3) The data collected by most systems is difficult to provide stable and reliable early warning, let alone bridge assessment

[0013] (4) The zero drift problem of the sensor for a long time is serious. It is difficult to distinguish which is the error of the sensor and which is the real response of the bridge. To solve the extremely complicated problem once and for all, the original intention itself has problems

[0015] (6) The monitoring technology is simple and easy to implement, but the evaluation technology involves many difficult problems such as inversion, optimization, data mining, damage identification, state evaluation, and bearing capacity evaluation, which are difficult for ordinary technicians to master

[0016] (7) In order to save costs, the monitoring of small and medium bridges adopts quasi-static sampling, and the data collection frequency is once every 5 minutes, which cannot capture the fleeting information of heavy vehicles

Moreover, the operation and maintenance cost of the low-cost system is extremely high, and the construction is often neglected. The system cannot work normally for a long time

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