软土地区盾构侧穿SF油罐扰动控制数值分析

Numerical Analysis of Disturbance Control of Shield Side Crossing SF Oil Tank in Soft Soil Area

摘要:

以宁波轨道交通3号线二期盾构隧道工程为背景，对软土地区盾构掘进过程中引起的SF双层油罐变形及应力分布规律进行数值模拟分析。结果表明，合理选取土体损失率、正面附加推力等参数值可有效控制油罐扰动。罐区变形以竖向变形为主，隆起量极值位于距离隧道较近的油罐，沉降量极值位于中心油罐区。距离盾构隧道较近的油罐壁出现较大附加应力，油罐各项应力值均小于罐体材料许用应力。油罐满载工况下变形及附加应力值均低于空载工况。现场监测数据时程变化趋势与数值分析结果一致，地表变形量及变形速率满足监测要求。

Abstract:

Based on the second phase shield tunneling project of Ningbo Rail Transit Line 3， the deformation and stress distribution of SF double-layer oil tank caused by shield tunneling in soft soil area are analyzed by numerical simulation. The results show that the disturbance of oil tank can be effectively controlled by reasonably selecting the parameters such as soil loss rate and frontal additional thrust. The tank farm deformation is mainly vertical deformation， the extreme value of uplift is located in the oil tank near the tunnel， and the extreme value of settlement is located in the central oil tank farm. The oil tank wall close to the shield tunnel has a large additional stress， and all stress values of the oil tank are less than the allowable stress of the tank material. The deformation and additional stress values of the oil tank under full load condition are lower than those under no-load condition. The time history change trend of field monitoring data is consistent with the numerical analysis results， and the surface deformation amount and deformation rate meet the monitoring requirements.