Study On Bridge Foundation Position Of Longjiang Bridge In Baoteng Expressway

The Longjiang Bridge which has been ready to build in the highway between Baoshan and Tengchong will span Longjiang river. The Longjiang Bridge will use Single-span steel box girder suspension. The abutment location has been set on the basalt slope of the valley deep near 100m. The change of the abutment's position is not only related to the slope stability, the safety of bridges and also directly to the technical specifications and cost of them.The studing of the thesis has the important engineering practical meaning.To determine the abutment's position, the thesis uses the consolidated methods to locate the bridge foundation position, which methods are engineering geologic analysis and the experienced formula of the natural stable slope angle and the numerical simulation. Firstly, analysis of field survey conduct slope stability of Longjiang Bridge under natural state, preliminary determine the failure mode of the slope. The results showed that under the natural state, due to weathering and gravity, causing a small amount of cross-strait top of the hill may have collapsed, but the overall slope is stable. Using the formula proposed abutment locations to determine the consult position and the stable angle of slope. Using the Finite Element Method analysis mechanical behavior of rock slope, results showed that when the bridge foundation set up in the stable slope line, the load stress on the rock side slope is very small and will not affect the overall stability of the slope and the safety of the bridge foundation. The generated displacement by the load also does not affect the safety of slope and abutment.In this thesis, various methods were comprehensive used to determine the bridge location, proposing the bridge foundation design of high slope position and slope stability analysis. The thesis has the certain reference values for the similar spot.