Long-term settlement prediction of high-speed railway bridge pile foundation

YANG Qi(杨奇)^{1, 2}, LENG Wu-ming(冷伍明)¹, ZHANG Sheng(张升)¹, NIE Ru-song(聂如松)¹, WEI Li-min(魏丽敏)¹, ZHAO Chun-yan(赵春彦)¹, LIU Wei-zheng(刘维正)¹

(1. School of Civil Engineering, Central South University, Changsha 410075, China;
2. Mobile Post-doctoral Stations of Traffic and Transportation Engineering,
Central South University, Changsha 410075, China)

Abstract:The process and characteristics of loading on high-speed railway bridge pile foundation were firstly obtained by means of field research and analysis, and the corresponding loading function was presented. One-dimensional consolidation equation of elastic multilayered soils was then established with single drainage or double drainages under multilevel loading. Moreover, the formulas for calculating effective stress and settlement were derived from the Laplace numerical inversion transform. The three-dimensional composite analysis method of bridge pile group was improved, where the actual load conditions of pile foundation could be simulated, and the consolidation characteristics of soil layers beneath pile were also taken into account. Eventually, a corresponding program named LTPGS was developed to improve the calculation efficiency. The comparison between long-term settlement obtained from the proposed method and the in-situ measurements of pile foundation was illustrated, and a close agreement is obtained. The error between computed and measured results is less than 1 mm, and it gradually reduces with time. It is shown that the proposed method can effectively simulate the long-term settlement of pile foundation and program LTPGS can provide a reliable estimation.

Key words:bridge pile foundation; long-term settlement; consolidation; Laplace numerical inversion transform; multilevel loading; multilayered soils