混凝土夯扩桩和土工格室加固铁路基床试验研究

Test study of reinforcing railway subgrades by using concrete compacted base-enlarged piles and geogrids

为了考察半干硬性混凝土夯扩桩与土工格室联合作用加固既有线路基基床病害的效果,结合达成铁路k337段成都黏土(膨胀土)基床病害工点的整治,选取了3个测试断面,分别测试了经不同加固方案处理后的轨道平顺性与基床不同高度处在机车荷载作用下的动应力、振动变形和加速度等动力响应。试验表明,3个测试断面的动力作用水平均在合理的范围内,动力学指标均低于相关限值;行车速度对动应力、动位移、加速度都有不同程度的影响。其中,加速度随行车速度的提高而增大最为明显;线路的平顺性与稳定程度对线路及路基结构的动力学(动应力、振动变形、加速度)响应有显著影响。

Three test sections were designed to investigate their effectiveness in reinforcing railway subgrades by using concrete compacted base-enlarged piles and geogrids based on the construction practice in the k337＋665 ？ ＋770 section of the Da-Cheng Railway.Track smoothness and associated dynamic responses such as the stress,dynamic deformation and acceleration rate under the locomotive load are recorded during the tests.Test results show that the dynamic response in test sections is below the relevant limits.Running speed has an different impact,and the rule of acceleration increase with run-up is most obvious.Smoothness and stabilizing of railway have remarkable influence on dynamic responses such as the stress,dynamic deformation and acceleration rate in railway line and subgrade structure.