在山区修建高速铁路时,由于山区地形地质条件复杂,往往容易引起山区铁路路堤的整体或局部破坏。随着土工加筋技术的发展,越来越多的山区铁路路堤采用土工合成材料加筋的方式来解决路堤的变形破坏问题,但倾斜地层条件下的土工加筋路堤的动力响应特性和变形规律尚不明确。由此,本文基于倾斜基岩加筋铁路路堤与无倾斜基岩加筋铁路路堤的模型对比试验,开展倾斜地层条件下土工加筋铁路路堤的动力响应特性研究,对土工加筋铁路路堤的竖向位移、加速度、动土压力以及土工格栅应变的变化规律进行对比分析,探究倾斜地层条件下的土工加筋铁路路堤的动力响应特性。结果表明：倾斜基岩路堤的竖向峰值位移要略大于无倾斜基岩路堤,且随着加载频率的增加,路堤的竖向峰值位移都有所减小。倾斜基岩路堤的竖向峰值加速度与竖向峰值动土压力明显大于无倾斜基岩路堤的工况,且两者的竖向峰值加速度与峰值动土压力都随加载频率的增大而增大,随埋深增加而减小。当埋深相同时,路堤加载中心下方的土体竖向峰值加速度与峰值动土压力最大,远离基岩侧次之,靠近基岩侧最小。路堤的格栅峰值微应变都随着格栅埋深的增加而减小,且靠近路堤顶部的两层格栅衰减幅度较小,而在相同加载频率下,倾斜基岩加筋路堤的格栅峰值微应变约为无倾斜基岩加筋路堤的两倍。

It is often easy to cause overall or local damage of railway embankment in mountainous areas due to the complex topographic and geological conditions when constructing high-speed railway. With the development of geotechnically reinforced technology, more and more mountain railway embankments adopt geosynthetics reinforcement to solve the deformation damage of embankments, however, the dynamic response characteristics and deformation law of geotechnical reinforcement under inclined stratum conditions are still ambiguity. Therefore, based on the model comparison test between railway embankment with inclined bedrock reinforcement and without inclined bedrock reinforcement, this paper carries out the research on the dynamic response characteristics of geotechnically reinforced railway embankment under inclined stratum conditions. And a comparative analysis on the changing rules of the vertical displacement, acceleration, dynamic soil pressure, and geogrid strains of geotechnically reinforced railway embankment was conducted. It aimed to investigate the dynamic response characteristics of geotechnically reinforced railway embankment under inclined stratum. The results showed that the vertical peak displacement of the inclined bedrock embankment is slightly larger than that of the uninclined bedrock embankment, and the vertical peak displacements of both cases decrease with the increase of loading frequency. The vertical peak acceleration and vertical peak dynamic soil pressure of the inclined bedrock embankment are obviously larger than those of the uninclined bedrock embankment, and both of them increase with the increase of loading frequency and decrease with the increase of burial depth. When the depth of burial is the same, the soil below the loading center of the embankment has the largest peak vertical acceleration and peak dynamic soil pressure, followed by the side away from the bedrock, and the side near the bedrock has the smallest. The peak micro-strain of the grids of the embankment all decreased with increasing depth of embedment of the grids, and the two layers of grids near the top of the embankment decayed less, whereas the peak micro-strain of the grids of the inclined bedrock-reinforced embankment was about twice as much as that of the uninclined bedrock-reinforced embankment at the same loading frequency.

国家自然科学基金(52108299 52178312 U2268213)