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| nvestigation on soil arching effect in visual model test of pile-supported embankment |
| CUI Xiaoyan1，ZHUANG Yan1，XIAO Henglin2，ZHANG Jun3，ZHANG Junhui4 |
| (1. Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education，School of Civil Engineering，Southeast University，Nanjing，Jiangsu 210096，China；2. School of Civil Engineering，Architecture and Environment，Hubei University of Technology，Wuhan，Hubei 430068，China；3. Shanxi Transportation Research Institute Group Co.，Ltd.，Taiyuan，Shanxi 030006，China；4. National Engineering Laboratory of Highway Maintenance Technology，Changsha University of Science and Technology，Changsha，Hunan 410004，China) |
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Abstract The shape of soil arch has not been generally recognized in the piled embankment，hence，further investigation on the soil arching effect has significant scientific research value for the analysis of load transfer mechanism in the piled embankment. The visualized model test device，materials used in the model test and the layout of the measured instruments to analyze the soil arching effect in piled embankment were firstly introduced. The distribution of the settlement and the vertical stress in the piled embankment were then investigated by carried out ten model tests based on this visualized device，in which the height of embankment and the pile spacing were varied. The experimental results showed that that the embankment height h and the clear pile spacing (s?a) are the key parameters for the generation of soil arching effect. For the plane strain condition，when h/(s?a)≤1.0，it can be concluded that the soil arching effect is not generated since the re-established vertical stress in the embankment was not occurred；for the ratio of h/(s?a) is in the range of 1.0–1.5，partial soil arching is formed；whereas when h/(s?a)≥1.6，the soil arching effect fully developed and the inflections of the vertical stress along the height of the embankment were founded，which is similar to the distribution of the vertical stress of embankment derived from the Hewlett & Randolph method. The experimental results also showed that the differential settlement at the surface of the embankment gradually decreased with increasing the embankment height，and approaching to zero for the value of h/(s?a) larger than 1.6. Finally，the equation of the inner and the outer height of soil arching were derived based on the experimental results，which were used to modify the analytical method proposed by Hewlett & Randolph. It can be found that the modified analytical method agreed well with the experimental results.
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2020, Vol. 39 
