基坑支护桩永久存在对地下室外墙土压力分布的影响

为研究地下室外墙土压力分布状态与基坑支护桩的关系,探究支护结构和地下主体结构在永久工况下的相互作用机理,借助Plaxis-3D有限元软件对采用桩锚支护的某基坑工程进行全工况的有限元模拟,发现支护桩的存在对地下室外墙土压力分布有明显的影响:土压力沿深度方向先增大后减小,呈弧线形分布;地下室外墙最大内力明显减小,挡土能力显著增强。通过对多个工程的模拟结果进行拟合得到地下室外侧土压力分布曲线,对该曲线简化后进行地下室外墙内力的计算分析。计算结果证实,按简化曲线计算所得地下室外墙内力与模拟值较为吻合,即该简化曲线在济南市工程地质条件下具有较好的适用性,可为支护桩存在条件下的地下室外墙设计提供参照。

Soil pressure distribution behind the basement wall considering the permanent existence of foundation pit retaining piles

In order to study the relationship between the soil pressure distribution behind the basement wall and the foundation pit retaining piles, and explore the interaction mechanism between the supporting structure and the underground main structure under the permanent, a Plaxis-3D simulation for a pile-anchor retaining pit was carried out. The results showed that the soil pressure distribution was evidently affected by the piles. The soil pressure increased at first then decreased along with depth, showing an arc shape distribution. The maximum internal force on basement exterior wall decreased and the soil retaining ability strengthened obviously. By fitting the simulation results of several practical engineering, the soil pressure distribution curve was derived and the curve was further simplified to analye the internal force on basement exterior wall. Results proved that the force which was calculated by the simplified curve could well agree with the simulated values. The simplified curve had good applicability in engineering geological condition of Jinan, and provided references for basement exterior wall design when supporting piles existed.