Model Test Of The Effect Of Active Ground Fissure On High-speed Railway Bridge

The ground fissure hazards has seriously threatened the express railway construction ofour county. The background of this paper is Datong-Xi’an express railway, which willconnected Shanxi and Shaanxi provinces and passed through the ‘Fen Wei garben system’.The garben system is famous for the development of typical active faults and ground fissures,thus will threaten the construction of Datong-Xi’an express railway. However, there are alittle research about the impact of ground fissure to express railway bridges in our county atpresent. Therefore, the influence mechanism research of ground fissure to express railway inthis paper is not only very meaningful, but also can be an important reference basis for safetyconstruction.Firstly, the paper briefly descript the region geology along the Datong-Xi’an expressrailway. Secondly, discuss the bridge deformation behavior, failure mode and influence scopewhile the express railway oblique crossing the ground fissure belt with45°in the1：20measuring scale model test, and taking the Shuixiu ground fissure as the model sample. Last,using numerical simulation software MIDAS/GTS to calculate the express railway obliquecrossing the ground fissure belt with45°, compare the numerical simulation results to themodel test results and offer some mitigation measures to express railway bridges crossingground fissure. The results of the two plans can provide a powerful scientific theoretical basisof design and construction safety to Datong-Xi’an express railway.The main subjects drawn from the paper are as follows：(1) The ground fissure mainlyaffect express railway bridge structure which crossing it, and box girders and rails haveobvious strains, other parts of express railway bridge structure have little changes;(2) Thefailure area of bridge model are113cm of hanging side and82cm of heading side, and theinfluence scope are147cm of hanging side and82cm of heading side, thus, the fortified rangeis229cm;(3) The bridge span in the test is feasible and can be optimized to reach the disasterrelief by optimization the reinforced concrete piles, increasing the bearing platform and bridgepier size, strengthen the Collapse-proof design and improving the ration of concrete;(4)Establish monitoring warning system to long-term observe the bridge deformation andresponse the impact of ground fissure activity in time.