Up till now

the theories of reinforced cushion cannot meet the needs of practice

the designing method of reinforced lime-soil cushion attracts most researchers’ attention. According to the ground treatment of the deep collapsible loess in the Zhengzhou-Xi’an Passenger Dedicated Railway Engineering

the limit state theory model of the reinforced lime-soil cushion above pile is established; the loading feature is analyzed; and the design method is presented. Considering pile diameter

pile space

subgrade height and geogrid strength

the parameters such as the cushion thickness etc.

are analyzed. It is suggested that the double layer structure and the double direction reinforced geogrid with small elongation rate should be used first to reinforced lime-soil cushion in the Passenger Dedicated Railway.