祁家渡黄河铁路大桥岸坡数值模拟分析

祁家渡黄河铁路大桥位于甘肃刘家峡水库库区。针对桥梁设计及施工过程中所面对的问题,通过现场调查、室内试验,掌握了桥址岸坡岩土体特征,之后建立二维及三维数值模型,利用FLAC3D软件对所建模型进行数值计算,得到两岸坡现状稳定系数、稳定岸坡角以及岸坡在施工过程中的应力应变状态。计算结果表明:岸坡整体处于稳定状态;岸坡位移及应力集中主要分布于卸荷裂隙带范围内;桥墩基槽开挖可能导致基坑后壁局部失稳。最终,根据稳定性分析结果提出相应支护建议,以达到保证桥址岸坡稳定的目的。

Numerical Simulation of Qijiadu Yellow River Railway Bridge Bank Slopes

The Qijiadu Yellow River Railway Bridge is located in the Liujiaxie Reservoir .In order to solve the problems which may occur during the design and construction of the bridge ,the character of the material in slope bank is analyzed through investigation on the site and laboratory experiments .2D and 3D models were developed .Based on qualitative analysis ,the stability coefficient of bank slopes ,the safety angle of bank and the change of stress and strain field during construction of the bridge are obtained using numerical simulation software (FLAC3D ) .The analysis result show that :The bank slopes are in the stable state ;The unloading fissure zone with obvious stress concentration phenomenon is more likely to damage;The excavation of slope may cause unstable state in the back wall .Finally prevention measures are pro-posed based on the analysis .