【摘要】 以新建污水隧洞下穿北京地铁2号线工程为背景,建立三维数值模型研究列车荷载、不同开挖顺序对既有结构沉降的影响以及不同埋深与最大沉降的关系。结果表明:考虑列车荷载后隧洞开挖引起的地铁结构最大沉降1.62 mm,大于不考虑列车荷载引起的最大沉降0.54 mm;先开挖中洞引起的沉降小于先开挖侧洞引起的沉降;各点的最大沉降值与埋深近似符合对数函数关系。最后将现场监测数据与数值计算结果进行了对比,两者沉降规律、变形特点及沉降值基本一致,验证了数值模拟预测的合理性。更多还原

【Abstract】 A newsewage tunnel project under line 2 of Beijing metro was studied in this paper. A three-dimensional numerical model was built to analyze the effect of train loads and excavation sequence on settlement of existing subway structure and the relationship between embedment depth and maximumsettlement. The maximumsettlement due to the tunnel excavation is 1. 62 mmwith consideration of train loads,greater than 0. 54 mmsettlement without consideration of train loads. When the middle tunnel hole was excavated as the first hole,the settlement was less than that when the side hole was excavated. The maximumsettlement is logarithmic to the embedment depth. By comparison ofin-situ monitoring data and calculation results,the characteristics of settlement and displacement are close,validating the prediction of numerical simulation.更多还原