The task of bridge load test is determined by the purpose and requirements.Generally speaking, the main tasks of the bridge load test are:

1 Determin the bearing capacity of bridge structure and operation conditions

(l)For important bridge structures, in addition to the necessary experimental study in the design phase, we usually authenticate the quality ,operation conditions of bridge and judge the actual bearing capacity by loading test.(2)For those bridges that need rebuilding or strengthening,the bridge load test can provide further modified technical basis,especially important for decreasing technical data.(3)For those complicated-new type bridge structure or those adopt new materials,new technology,we can understand and grasp the actual stress condition of structure,verify the structural calculation scheme,explore the universal laws by system load test,thus can accumulate scientific data for the enrichment and development of the bridge structure calculation theory and construction technology.

2 Analyze the reasons of bridge disease and its change rule

For those bridge structure that suffered floods,freezing,earthquake,impact,dig or erosion to damage,or found having serious defects during bridge construction or use, such as excessive deformation or fracture,we often conduct comprehensive analysis and research by the bridge load test,then reasonable treatment scheme and maintenance measures are put forward.

3 Check the immanent quality of bridge structure

Identify the completion inspection and acceptance for those new types of,reforcement and reconstructed bridge to evaluation whether the overall mechanical properties of the bridge meet the design requirements and standards,test the expected design effect.