地铁循环荷载作用下上海软土路基的长期沉降计算

Long-Term Settlement Calculation of Shanghai Metro Soft Soil Foundation Under Cyclic Loading

采用数值模拟与经验方法相结合,计算地铁循环荷载作用下轨道地基的长期沉降。以人工数定激励力法模拟列车荷载,以FLAC 3D软件建立隧道以及周围土体的数值模型,计算第1次加载后模型的变形和应力。分别结合3种不同的经验算法,以分层总和法计算轨道地基的长期沉降,结果表明:3种算法计算得到的长期沉降和年沉降量分布规律相似,均随深度的增大而增大;算法2所得的平均沉降的计算值结果偏大,算法3偏小。

This paper focuses on the calculation of long-term settlement of metro foundation under cyclic loading caused by train moving loads in Shanghai soft soil. In order to save calculating time, numerical method is com- bined with the experiential ones, based on the FLAC 3D software, which can set up the settlement calculating model considering tunnel and surrounding soil. The deformation and stress of the model can be simulated under the first cyclic loading. Then the long-term settlement of metro foundation under cyclic loading is calculated by three experiential methods. The results show that the distribution of long-term and yearly settlement calculated by 3 methods is similar to each one. The settlement increased with depth. The average long-term settlement cal- culated results of Method 2 are bigger than Method 1, while Method 3 smaller than Method 1.