结合型式对地铁车站上盖物业的振动响应影响

Influence of Combination Types on Vibration Response of Superstructure of Subway Station

为研究地铁振动对不同结合类型地铁车站及其上方的动力反应影响,基于地铁车站与上盖物业连接型式的主要承载区别,提出“软结合”“硬结合Ⅰ”“硬结合Ⅱ”3种结合型式;然后,采用车-轨耦合模型得到列车荷载谱,利用有限差分软件FLAC^(3D)建立地铁车站-上盖物业数值仿真模型,并与实测数据进行对比,验证数值仿真模型与参数的正确性;最后,基于数值仿真,从时域、频域出发,研究3种结合型式下上盖物业的振动响应.研究结果表明:软结合型式下站厅层到上盖物业一层加速度峰值减小69.10%,硬结合Ⅰ型减小2.08%,硬结合Ⅱ型增大2.94%,硬结合型式下上盖物业振动加速度较软结合型式大;3种结合型式下上盖物业振动的频率主要在40~90 Hz,且对于上盖物业同一楼层,振动随距振源距离的增大而逐渐减小;软结合型式下上盖物业一层加速度级最大值为68.2 dB,较站厅层减小11.3 dB;硬结合Ⅰ型、硬结合Ⅱ型的上盖物业加速度级最大值分别为83.4、79.4 dB;地铁振动造成上盖物业附加第一主应力很小,且在向上传播过程中衰减很快;从站厅层到上盖物业,软结合型式第一主应力衰减85.81%,硬结合Ⅰ、Ⅱ型式分别衰减63.46%、72.27%,间隔土对附加应力有明显衰减作用.在地铁实际建设工程中建议选用软结合型式.

In order to study the effect of subway vibration on the dynamic response of different types of subway stations and their superstructures,three kinds of combination types,namely“soft combination”,“hard combinationⅠ”,and“hard combinationⅡ”were proposed based on the differences in the main bearing of the connection between the subway station and the superstructure.The train load spectrum was obtained by means of the vehicle-rail coupling model,and a numerical simulation model of the subway station-superstructure was established using finite difference software FLAC^(3D) and compared with measured data to verify the correctness of the model and the parameters.Finally,the vibration response of the superstructure under the three kinds of combination types was studied based on numerical simulation from the time domain and frequency domain.The results show that the acceleration peak from the station hall to the first floor of the superstructure decreases by 69.10%under the soft combination and 2.08%under the hard combinationⅠ,but it increases by 2.94%under the hard combinationⅡ.The vibration acceleration of the superstructure in the hard combinations is larger than that in the soft combination.The vibration frequency of the superstructure under the three kinds of combination types is mainly 40–90 Hz.In addition,for the same floor of the superstructures,the vibration decreases with the increase in the distance from the vibration source.The maximum acceleration level of the first floor of the superstructure under the soft combination is 68.2 dB,which has decreased by 11.3 dB compared with that of the station hall layers.The maximum acceleration level of the superstructure under the hard combinationⅠand hard combinationⅡis 83.4 dB and 79.4 dB.The first principal stress attached to the superstructure is very small due to subway vibration,and it attenuates quickly in the upward propagation process.From the station hall to the superstructure,the attenuation of the first principal stress of the soft combination is 85.81%,and that of the hard combinationⅠand hard combinationⅡis 63.46%and 72.27%,respectively.Furthermore,the spacer soil attenuates the additional stress obviously.It is suggested to choose the soft combination in the actual construction project of subways.