路基区段双块式无砟轨道基础上拱整治技术对策

针对路基区段双块式无砟轨道基础上拱问题,通过典型基础上拱工点调研、有限元计算分析、工程实践应用,对高速铁路路基区段双块式无砟轨道基础上拱整治技术进行研究。研究结果表明:路基区段双块式无砟轨道基础上拱病害可以通过切割承轨台、切割支承层及暗挖基床技术进行整治;切割承轨台整治措施工程量小,但调整量也较小,适用于局部上拱且需应急整治的工况;支承层减薄会使得列车荷载下的结构应力集中明显,垂向压应力增加,且调整量有限,适用于变形稳定的上拱区段整治;暗挖基床整治措施工艺较为成熟,可多次作业,能根本上消除填料膨胀上拱,特别适用于基床及路基填土部分膨胀引起上拱的工点。形成的技术措施及经验可为不同线下基础高速铁路无砟轨道基础上拱整治提供借鉴。

Remediation Technology of Foundation Upwarping of Double-block Slab Ballastless Track on Subgrade Section

To solve the problem of foundation upwarping of double-block slab ballastless track on subgrade section,based on the investigation of typical upwarping place on the foundation,finite element analysis and engineering practice application,the upwarping remediation technology of the double-block slab track within high-speed railway subgrade section was studied.The research results show that the upwarping of double-block slab track on subgrade section can be remediated by cutting the bearing platform,cutting support layer and undercutting subgrade bed.The amount of construction of cutting bearing platform remediation measure is limited,and the adjustment amount is also limited,which is suitable for the condition of partial upwarping and emergency remediation.The thinning of the support layer may cause the stress more concentrated and greater vertical compressive stress under the train loading,and the adjustment amount is limited;thus,it is suitable for the remediation of the upwarping section with stable deformation.The undercutting subgrade bed remediation measure is relatively mature and it may be operated many times,eliminating the upwarping caused by packing expansion fundamentally.Therefore,it is especially suitable for the upwarping place caused by the expansion of the subgrade bed and the subgrade filling part.The technical measures and experience are expected to provide guidance for the treatment technology of foundation upwarping of ballastless track of high speed railway on different track formation foundation.