无砟轨道桩板结构路基设计计算

鉴于无砟轨道桩板结构路基没有相应的设计规范,在分析其结构特点和使用要求的基础上,借鉴相关行业标准和研究成果,将荷载分为永久荷载、可变荷载和偶然荷载,提出按承载能力极限状态和正常使用极限状态分别进行荷载效应组合,取各自的最不利组合以分项系数形式的表达式进行桩板结构路基设计计算。对荷载分项系数、组合值系数、准永久值系数以及结构抗力设计值和正常使用规定限值提出建议值。建议:承载板长度宜取20~50 m、厚度宜取0.5~0.8 m,并按一定原则设置;桩间距纵向宜取5~10 m,横向宜与线间距相对应;设置过渡段以满足过渡衔接处差异沉降和竖向转角要求。

Design and Calculation Method for Pile-Slab Structure Roadbed of Ballastless Track

In view of lacking in corresponding design code for pile-slab structure roadbed of ballastless track, based on the analysis of its structure characteristics and application requirements, and using the design code as well as research achievements of correlative fields as reference, the roadbed load is divided into permanent load, variable load and accidental load. It is proposed to carry out load effect combination according to the limit state of carrying capacity and the limit state under normal operation. The most unfavorable combination of each state is chosen to carry through design calculation for pile-slab structure roadbed in the form of subentry coefficient expression. The suggested values are given for load subentry coefficient, combination value coefficient, quasi-permanet value coefficient, the design resistance of structure and the limit state under normal operation. The paper also suggests that the appropriate length and thick- ness of load bearing slab should be 20-50 m and 0.5-0.8 m respectively, and should be set up according to certain principle. Pile spacing in longitudinal direction should be about 5- 10 m, and pile spacing in transverse direction should be corresponding with the railway line spacing. Transition section should be es- tablished in order to satisfy the requirement of difference settlement and vertical angle of pile head.