铁道科学与工程学报2025，Vol.22Issue(3)：1052-1063,12.DOI:10.19713/j.cnki.43-1423/u.T20240754
预应力微型桩动态调控软岩路基上拱效果研究
Effect of dynamic regulation of prestressed micro-piles on upheave of soft rock roadbeds
摘要
Abstract
In order to propose an engineering measure to economically and efficiently regulate the heave deformation of red-layered soft rock roadbeds and to reveal the mechanism.The relationship between different prestresses(50,100,150,and 200 kN)and the vertical displacement of pile tops was measured indoors by using a self-developed test device with dynamically adjustable heave deformation.Numerical analyses were conducted to study the effect of single piles(with pile lengths of 8,10,and 12 m)and pile groups(with pile spacings of 3D,4D,5D,and 6D)in regulating the heave deformation of red-layered soft-rock roadbeds,when the pile diameter D is 0.17 m.Indoor test results indicate that the prestressed micropiles can effectively control heave deformation.However,the control capacity does not increase linearly,therefore necessitating real-time monitoring of the heave deformation values and dynamic adjustment of the prestressing force.Numerical simulations reveal that,under the working condition without any treatment measures,the heave deformation of the test section due to wetting effect and lateral ground stress is about 9.5 mm.The heave deformation distribution curve decreases sharply at the pile-forming position for 8 m,10 m,and 12 m long prestressed micropiles under single pile regulation.The increase of pile length and prestressing can cause a small increase in the regulation range,and the maximum value of the regulation area fluctuates in the range of 2～3 times the pile diameter.Prestressed pile groups with 12 m length and 5D spacing can balance safety and economy,reducing the heave deformation near the track to 3.2 mm(a decrease of 66.3%),2.9 mm(a decrease of 69.5%),and 3.5 mm(a decrease of 63.5%),ultimately meeting the specification requirements for heave deformation control.The regulation ability of pile groups is significantly enhanced after applying prestressing,reaching about 1.4 times that of the unprestressed condition.The research results can provide a reference for addressing the heave of red-layer soft rock roadbeds in high-speed railroads.关键词
预应力微型桩/红层软岩/高铁路基/上拱变形Key words
prestressed micro-piles/red-bed soft rockmass/high-speed railway subgrade/heave deformation分类
建筑与水利引用本文复制引用
张锐,张喜伟,罗辉,余雷,刘正楠..预应力微型桩动态调控软岩路基上拱效果研究[J].铁道科学与工程学报,2025,22(3):1052-1063,12.基金项目
国家自然科学基金资助项目(52278432) （52278432）
中国国家铁路集团有限公司科技研究开发计划项目(K2019G045) （K2019G045）
