沈阳砂土地区桩锚支护结构的内力研究及数值模拟

Research and Numerical Simulation for Internal Force of Pile-anchor Support Structure in Sand-clay Area of Shenyang

现行设计规范一般将三维基坑问题简化为二维平面应变问题进行分析计算,不能反映基坑的空间效应。通过数值模拟,将FLAC3D模拟数据与经典法、弹性法比对,找出三维状态下桩锚支护结构的应力以及受力特点。结果表明:对于基坑内侧受拉的负弯矩,等值梁法更为准确,弹性法与模拟值相差较大;悬臂状态时,等值梁法能更为准确反映受力情况等。

Current design codes usually make the deep excavation problem which is a 3-D space structure system simpli-fied as a 2-D plane strain problem to calculate and analyze ,which could not reflect the spatial effect .Through the nu-merical simulation ,the FLAC3D simulation data was compared with the classic method and elastic method to identify the characteristics of the stress and forcing for the pile-anchor support structure under the 3-D condition .The results suggest that for the negative moment suffering the tension inside the excavation ,the equivalent beam method is more accurate , but the elastic method is very different from the simulation ;For the cantilever state ,the equivalent beam method can more accurately reflect the forcing and so on .