Piled embankment to prevent damage to pipe buried in soft grounds undergoing lateral flow

Abstract

Lateral flow of soft ground occurs when embankment filling is performed on reclaimed land of foreshore. If a utility pipe is buried in soft ground undergoing the lateral flow, severe damage to the pipe can be caused. A pile-supported embankment has been used to support embankment to minimize lateral flow of the soft soil by transferring the embankment loads through the piles to the firm layer. To prevent damage to the buried pipe subjected to lateral force of the soft ground, full-scale field experiments on the piled embankment were conducted for 70 days. The test results show that the piled embankment effectively reduces both the settlements of the ground and the lateral displacements of the buried pipe. Although additional load was not imposed on the embankment after finishing embankment filling, the settlement and lateral displacement of soft ground simultaneously increased. This coupling behavior was observed at the toe of the embankment and the back of the buried pipe. To quantitatively evaluate the coupling effect of the movement, the coupling area (CA) was coined and analyzed with the efficiency of load transfer. The efficiency evaluated by the CA was in good agreement with the efficiency by the soil arching mechanism.

Mitigating effect of embankment to adjacent pipe with CDM columns

“…These lead to the increase of the risk of suffering from various adverted soil-related phenomena. Some of them are: crossing the ground faults [1], [2], land sliding [3,4], tunnel constructing [5], [6] or deformation of the soil due to the appearance of the embankment [7], [8], [9]. Among these threads, the use of embankment on soft soil is recorded as a significant reason for failure to be occurred, which needs reinforcement for the natural soil.…”

“…Among these threads, the use of embankment on soft soil is recorded as a significant reason for failure to be occurred, which needs reinforcement for the natural soil. For instance, Hong et al in [7] has reported the experiments that the lateral displacement of pipe can be up to 200 mm after 30 days. The reinforcement using columns in the soft soil thus proposed as the solution for mitigated approach.…”

“…Analogously, Huang et al in [8] recorded a larger than 200mm vertical settlement on the surface of soft soil with the reinforcement from concrete columns. Reinforcement using concrete is also the commonly choice in such cases [7], [8], [9]. Besides, the appearance of the displacement of pipe will lead to the well-known ring bending force which is widely recorded as the cause of curriculum stress increase [10], decrease of safe factor [11] and coupling with in-plane bending to reach much higher equivalent stress in pipe [12].…”

Numerical and Theoretical Study on the Settlement of Capped Piles Composite Foundation under Embankment

“…Capped piles are frequently used in pile-supported embankments [4] or pile-net composite foundations [5]. Engineering experiences had shown that composite foundations with capped piles effectively reduced the settlement and the failure of embankments on soft soils [6][7][8][9], especially in highspeed railway and highway engineering [10,11].…”