The field test for influence of ram-compacted piles with bearing base on settlement of embankments in China Beijing-Shanghai high-speed railway on deep soft soil

Abstract

The stratums along the Beijing-Shanghai high-speed railway are composed mainly with soft soil. The foundation of roadbed were strengthened in hope of reducing differential and total settlement. Ram-compacted piles are mentioned in this paper, as an example of strengthening methods. Using joint test method combining liquid level settlement gauges and single point settlement gauges, total settlements and compressions at different depths were measured. Field test results showed that：1. The settlements were significantly reduced. 2. The settlement of the basement with cap at the middle of roadbed mainly appeared during filling stage, and that without cap indicated a 30-day-stablisation during preloading stage. 3. The up thorn can be decreased by pile cap. 4. The largest settlement was found at roadbed center, whereas the smallest occurred at embankment toe. Ram-compacted piles successfully reduced settlement of roadbed, offering reference value to high-speed railway design.

Research on Vertical Bearing Capacity of Ram-compacted Pile with Vibrating Gravel Base in Collapsible Loess Foundation

“…Under this background, an innovative construction technique named ram-compacted piles with vibrating gravel base was invented in soft clay areas which can effectively reinforce foundation of industrial and civil architecture, even that of railway engineering. According to the statistics of field tests conducted by Ma [3], ram-compacted piles with vibrating gravel base is capable to reduce settlement of roadbed in soft soil areas efficiently. What is more, a series of research by Chen [4] indicated that the improvement of properties of adjacent soil surrounding piles can increase ultimate bearing capacity of foundation apparently.…”