单元双块式无砟轨道土工布设置研究

Study on laving earthwork cloth between unity double-block ballastless track

兰新(兰州—新疆)铁路第二双线路基段拟采用单元双块式无砟轨道,单元道床板直接浇筑在纵向连续的支承层上时,二者层间良好的粘结制约了道床板温度应力的释放,也给支承层自身带来了较大的附加应力,易引起结构产生裂缝,并破坏结构整体的稳定性。在对试验段长期观测的基础上对结构铺设土工布前后的力学性能进行分析,结合试验段推板试验,给出单元双块式无砟轨道土工布设置意见:道床板与支承层之间需要设置土工布,板中设置销钉/钢管桩时,土工布为道床板与支承层间提供的摩擦因数不能小于0.6,若支承层设置纵向锯齿槽,土工布可以选用一般材料。

The new Lanzhou--Xinjiang railway plans to adopt the unit of double block ballastless track, when the unit track concrete layer is directly built on the longitudinal continuous supporting layer, the bonding of them re- stricts on the release of temperature stress. At the same time, it takes much additional stress to the supporting layer, which makes the structure crack easily. In addition, it damages the structure integrity. Based on the long observation of the test section, the mechanical properties were analyzed and compared under the condition of hav- ing or having no laying earthwork cloth, meanwhile combining the test of push slab and the results of how to ar- range earthwork cloth under the unit of double block ballastless track were obtained. Firstly, the lay earthwork cloth is needed between the track concrete layer and the supporting layer. Secondly, the set dowels or steel tubu- lar should be piled in the middle of bed slab, and the frictional coefficient by the earthwork cloth between the track concrete layer and the supporting layer must be more than 0.6. If the supporting layer had longitudinal cog- ging, then the earthwork cloth can use ordinary material.