城区高速铁路盾构隧道轨下预制装配式箱涵结构受力分析

以北京-张家口高速铁路清华园隧道为依托,介绍了隧道轨下预制装配式结构,并从抗滑移、列车动力响应和地震响应3个方面对结构稳定性和安全性进行了数值模拟分析。结果表明:在不考虑预制箱涵结构顶部现浇回填层且忽略箱涵与管片间螺栓连接条件下,列车通过时在峰值压力作用下箱涵结构的最大竖向位移为0.035 mm,最大竖向应力为0.42 MPa;时速300 km列车通过时,预制装配式箱涵结构竖向位移、竖向动应力及竖向加速度的最大值分别为0.036 mm,64.2 kPa,0.84 m/s^2;地震荷载(汶川地震波)作用下最大水平、竖向位移分别为4.71,4.67 mm,最大水平、竖向应力分别为9.828 MPa,19.555 MPa。

Mechanical Analysis of Prefabricated Assembled Box Culvert Underrail Structure for Shield Tunnel of Urban High Speed Railway

Based on the Tsinghua Yuan Tunnel of Beijing-Zhangjiakou high speed railway,the prefabricated assembled under-rail structure for the tunnel was introduced,and the structure stability and safety was numerically simulated from three aspects including anti-sliding,train dynamic response and seismic response. The results show that the maximum vertical displacement and the maximum vertical stress of the box culvert structure are 0.035 mm and 0.42 MPa under the action of peak pressure when the train passes without considering the cast-in-situ backfill layer at the top of the prefabricated box culvert structure and by ignoring the bolt connection between the box culvert and the segments. The maximum values of vertical displacement,vertical dynamic stress and vertical acceleration of prefabricated assembled box culvert structure are 0.036 mm,64.2 kPa and 0.84 m/s^2 respectively when train passes with the speed of 300 km/h. The maximum horizontal and vertical displacements are 4.71 and 4.67 mm,and the maximum horizontal and vertical stresses are 9.828 MPa and 19.555 MPa respectively under earthquake load(Wenchuan earthquake wave).