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目的:旨在从宏细观角度探究桩承式路堤中土拱结构的形态特征及其演化规律。创新点:1.基于接触力链网络的细观统计与分析并结合土拱结构的特点,对路堤中的接触力链进行划分;2.从宏细观角度,揭示路堤中土拱结构的形态特征,并研究土拱结构随桩土相对位移增加的演化规律。方法:1.采用傅里叶级数近似法对接触力链组构各向异性进行统计与划分;2.基于路堤填料位移、接触力分布以及组构各向异性主方向等的分布及变化规律,从宏细观角度对土拱结构的形态及其演化规律进行综合分析。结论:1.土拱结构是由路堤中大于1.5倍接触力均值的强力链构成,而弱力链则主要起支撑作用。2.土拱结构随桩土相对位移的增加而历经倾斜剪切面→半圆形拱→悬链线形拱的演化规律,土拱结构的最大高度约为0.8倍桩净间距。3.路堤填料内摩擦角对土拱结构的形态及演化规律几乎无影响;路堤填筑高度对土拱结构形态则有显著影响;桩净间距对土拱结构的演化有一定影响,但是对其最终形态特征则几乎无影响。
Objective: To explore the morphological characteristics and evolution of soil arch structure in piled embankment from the perspective of macroscopic and microscopic. Innovative points: 1. Based on the meso-statistics and analysis of the contact force chain network and the characteristics of the soil arch structure, the contact force chains in the embankment are divided; 2. From the macroscopic and microscopic perspectives, the shape of the soil arch structure in the embankment is revealed Characteristics, and study the evolution of soil arching structure with the relative displacement of pile-soil evolution. Methods: 1.According to the Fourier series approximation method, the anisotropy of contact force chain was statistically calculated and classified; 2. Based on the distribution and variation of packing displacement, contact force distribution and main direction of anisotropy of structures , A comprehensive analysis of the morphology and evolution of soil arch structure is made from macroscopic and microscopic perspectives. Conclusions: 1. The soil arching structure is composed of strong chains whose average contact force is more than 1.5 times in the embankment, while weak chains mainly play the supporting role. 2. With the increase of pile-soil relative displacement, soil arching structure evolves through the evolution of inclined shear plane → semicircular arch → catenary arch. The maximum height of soil arch structure is about 0.8 times of the net spacing of pile. 3. The internal friction angle of embankment filler has almost no effect on the shape and evolution of soil arching structure. The height of embankment filling has a significant effect on the shape of soil arching. The net spacing of pile affects the evolution of soil arching structure. However, The final morphological characteristics are almost no effect.