Experimental analysis on settlement controlling of geogrid-reinforced pile-supported embankments on collapsible loess in high-speed railway

Abstract

Centrifugal model tests were performed to investigate the effectiveness of settlement control using geogrid-reinforced pile-supported embankments for high-speed railways on collapsible loess. First, the acceptability of using remoulded loess to simulate the behaviour of undisturbed collapsible loess in wetting test was examined in centrifuge tests. Then, the settlement of geogrid-reinforced pile-supported embankments under different conditions was investigated using remoulded loess. Experiments results showed that the collapse deformation process of remoulded and undisturbed collapsible loess can be divided into three stages with respect to time. The settlement of embankment built on collapsible loess foundation without improvement does not meet the post-construction settlement constraint for embankment of ballast track high-speed railways. Use of rigid piles, with or without caps, can significantly reduce embankment settlement and the rate of post-construction settlement. It was also observed that the negative skin friction developed in the piles varies with pile spacing and the pile configurations.

Keywords::

• embankment engineering
• collapsible loess
• rigid pile
• geogrid-reinforced pile-supported embankments
• settlement
• centrifugal test

Notes

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^2. Email: [email protected]

^3. Email: [email protected]

Additional information

Funding

This research is financially supported by the Nation High Technology Research and Development Program of China [grant number 2007AA11Z116] and the Scientific and Technological Program of the Ministry of Railways of China [grant number 2007G046].