水泥土挤密桩加固过渡段路基对平顺性影响研究
Track regularity influence study of reinforce bridge transition section by cement soil compaction pile

宁启铁路新丰河中桥过渡段路基承载力和Evd的检测表明,过渡段路基承载力严重不足,不能满足提速至200 km/h的要求。承载力不足引起过渡段路基出现道砟槽病害,路基表层动土压力峰值过大(达到196.03 kPa),轨道整体刚度和挠度不在合理值范围等问题,表明过渡段存在较大不平顺。过渡段采用了水泥土挤密桩加固,加固后路基顶面各测点的动土压力平均降低24.2%,轨道整体刚度平均提高23.14%,挠度降低31.40%,说明水泥土挤密桩可以较有效减缓过渡段不平顺问题。
Some site tests are carried out at Xin-feng river bridge transition section in Nanjing-Qidong existing railway, such as bearing capacity, dynamic elastic modulus(Evd). It is found that the subgrade bearing capacity is serious insufficient before reinforcement, and Evd value also can not meet the requirements of speed up to 200 km/h. Insufficient bearing capacity produces a series of problems, such as ballast groove disease, peak dynamic stress is too large (reach to 196.03 kPa), tracks stiffness and deflection value is not in reasonable range, etc. Because of these problems, the bridge-subgrade transition section is found to be not smooth. Cement-soil compaction piles were used to reinforce the transition section subgrade. After reinforcement, test shows that each measuring point average dynamic earth pressure reduced by 23.14%. At the sametime, track overall stiffness increased by 23.14% and deflection reduced by 31.40%. These results indicate that cement-soil compaction pile can effectively slow down the transition section irregularity problem