重载铁路翻浆病害聚氨酯半刚性层整治技术现场试验研究

Field Test Study on Polyurethane Semi-rigid Layer Remediation Technology for Heavy-haul Railway Mud Pumping

针对重载铁路翻浆冒泥病害这一"老大难"的问题,提出在基床表层增设聚氨酯碎石复合半刚性加强层结构,并开展材料力学特性试验、施工工艺以及现场测试三方面研究。研究表明:级配碎石掺9%聚氨酯胶水,孔隙率低、固化时间快、强度大、耐久性好,且混合料常温下初凝时间40 min,初凝强度5.4 MPa,满足天窗点施工和受力条件;半刚性结构层在包神重载铁路瓷窑湾站翻浆冒泥整治试验工点得到运用,施工工艺合理有效,能在有限的4 h封锁天窗时间内完成分段的翻浆冒泥整治工作;现场行车试验显示加强层具有较好的减振效果,减少线路维修、增加线路使用寿命,现场长期监测证明采用聚氨酯胶凝碎石结构层整治翻浆冒泥病害效果显著,聚氨酯半刚性层产生13.21 mm沉降,且后期沉降保持稳定。

In view of the big and difficult problem of mud pumping in heavy haul railway,this paper proposes to add polyurethane gravel semi-rigid composite layer structure on the surface layer of subgrade and runs a study on mechanical test,construction technology and field test.The research shows that the graded crushed stone meets the requirements for construction in dedicated maintenance time and acceptance of stress conditions when the dosage of polyurethane glue is 9%due to its low porosity,short curing time is short,high strength and good durability.Its initial setting time is about 40 min and initial setting strength is about 5.4 MPa.The semi-rigid structural layer is used in a mud pumping controlling test site located in the Ciyaowan railway station on Baotou-Shenmu Line.The construction technology is reasonable and effective.The remediation of mud pumping can be completed within a limited 4 hours of dedicated maintenance time in different stages.The train operation tests show that the strengthened layer has better damping effect,reduces track maintenance and increases service life of track.Long-term field detection proves that the polyurethane gravel semi-rigid composite layer structure has remarkable effect on the control of mud pumping,and only 13.21 mm of sedimentation is generated and subsequent settlement is stable.