An analytical solution for settlement of pile-supported reinforced low embankment considering lateral friction along pile shaft

Abstract

The settlement formula for pile-supported reinforced embankment is established by improving the elastic foundation beam method and combining the column unit method. The traditional Winkler beams is replaced by the Timoshenko beams, and the constraint of the height of fill can be neglected because the lateral friction on the pile side is considered in the column unit method. The presented method is employed to analyze a practical engineering and compared with other methods. The results are shown to be reasonable. The effects of the variation of parameters such as pile spacing (s), thickness of load transfer platform (LTP) (h) and tensile stiffness of the geosynthetic (S_r) on the pile lateral friction and the settlement of pile-supported reinforced embankment are investigated. As s/d increases, the elastic zone with lateral friction resistance becomes shorter and shorter. The plastic zones at both ends become longer and longer. The maximum settlement generally increases with the increase of s/d. When s/d ≤ 4, the maximum settlement increases little, but when s/d > 4, the maximum settlement increases large, and the rate is 4 ∼ 5 times of s/d ≤ 4. With the increase of h/s, the length of elastic zone due to pile side friction changes little, but the whole zone shifts upwards. The maximum settlement shows an obvious gradient increase. When h/s = 0.5 the maximum settlement is about 1.5 times of h/s = 0.3 maximum settlement. With the increase of S_r, the whole elastic zone of pile side resistance becomes shorter and shifts upwards. The maximum settlement decreases in a gradient way. The settlement at S_r = 4000 is about 0.75 times of that at S_r = 1000. This paper expands the settlement theory of reinforced embankment and is closer to the real conditions, which has certain scientific significance and application value.