Study And Analysis On The Index Bearing Capacity Evaluation Of The Small And Medium Span Concrete Bridge

In recent years, with China's rapid transport and the increasing transportation load, how to take full advantage of highway and bridges' safety reserves to continue to serve for road transport? It is necessary to assess the bridges' carrying capacity of the existing accurately. The bridge load test is one of the most effective, most direct and most convincing means of evaluation of the bridge bearing capacity. It can provide a more accurate assessment of a bridge's security reserve in the normal operating state by matching theory and its analysis.As the indicator of evaluating the carrying capacity of the bridge, calibration coefficient should have Strict definition and accurate methods of calculation. In our country, the evaluation of calibration coefficient for the ordinary reinforced concrete and prestressed concrete bridge under load testis only broad range of that in the references available. There is no division for their respective scope of it in accordance with Bridges structure.In this paper, the author refers to a large number of professional books and papers. on the basis of the "Xi'an - Zhashui" Highway, "Wuhan - Yinchuan provincial highway" to Xianyang- Yongshou paragraph, "Xi'an - Hefei, the western passage" throughout Shan'xi Lantian- Shangzhou Expressway Section B2-B6 load test a large number of bridges, the author makes analysis on various bridge-types' calibration coefficient and the specific work and research results are as follows:First ,the author summarizes the influencing factors about the calculated values of the bridge structure' calibration coefficient. And analyzes the ranges of calibration coefficients of various kinds of common and new bridges based on 51 common types bridges' load tests which are Personally participated in. It will enrich the calibration coefficient information on reserves of existing bridge bearing capacity of China's evaluation.Second, the author probes the Simplified calculation methods of common types of bridge-type. there will be a more accurate calibration coefficient of the structure by the Simplified calculation of Beam-Grid Method of 16 meters, 20 meters span simply supported, continuous prestressed hollow fabricated Panchiao, 20 meters, 25 meters, 30 meters, 40 meters long-span prestressed fabricated four separate small box room box girder bridge, half-through arch bridge of reinforced concrete. Third, as the existence of Shear-lag Effect of Box-Girder ,the single-beam calculation by using Plane-section assumption will be a bigger error while a more accurate calibration coefficient by using the theory of plate-shell element to model the structure for thin-walled cast-in-place concrete box girder bridges of single box and single chamber (double) .It will take a reference for the detection of workers at the scene to monitor the bridge test data.