北京地铁17号线南段混凝土道床承载力分析

Analysis on Bearing Capacity of Concrete Ballast in Southern Section of Beijing Metro Line 17

北京地铁17号线南段地下轨道部分主要道床形式为普通长枕式整体道床,施工工序中包含轨道车和平板车运送轨排、钢筋和混凝土等。为了缩短轨道车运送工序时间,减少卸车点至作业面距离,对普通长枕式整体道床进行混凝土浇筑后24 h道床承载力分析。检算结果表明:最不利情况下的枕上动压力为14.25 kN;轨枕弯曲强度(轨下截面正弯矩和枕中截面负弯矩)在允许范围之内;道床强度符合要求;混凝土抗剪强度符合要求。

The main track bed of the southern section of Beijing Metro Line 17 is an ordinary long pillow type integral track bed,and the construction process includes rail cars and flat cars transporting track bars,steel bars and concrete.In order to shorten the process time of rail car transportation and to reduce the distance from unloading point to working surface,the bearing capacity of ordinary long pillow monolithic roadbed was analyzed 24 hours after concrete pouring.The results show that the pillow dynamic load under the most unfavorable condition is 14.25 kN.The positive bending moment of the lower section of the rail and the negative bending moment of the middle section of the pillow are both within the allowable range.The pressure transfer meets the compressive strength requirements.The shear strength meets the requirements.