Study On Group Effect Of Cast-in-situ Concrete Thin Wall Pipe Pile Composite Foundation Under Road Embankment

Thin-wall pipe pile using cast-in-situ concrete (PCC pile in short) technique is a new ground improvement technology developed independently by Proc. Hanlong LIU et al, Geotechnical Institute of Hohai University. As a new type of pile, it has many advantages, such as, fast construction, economize concrete and improve soil with efficacy, increase the bearing capacity and reduce the settlement of deep soft soil. Many researchers have already analyzed the simple PCC pile composite foundation, while the mechanism and effect of group PCC piles is not clear, in particular under the road embankment in the high way. The study is launched to address the concept and mechanism of PCC group piles composite foundation. Following are the main works fulfilled.1. Introduce different experiments and concept methods for the rigid pile composite foundation; compare the result by using a small example, The PCC pile composite foundation design can make use of these conclusions.2. Based on the field test results of Shanghai XINWEI expressway, analyze the PCC pile group effect with the different height of road embankment and pile spacing. The PCC pile group coefficient can be calculated by the method of Yang keyi in considering the influence of soil load between two piles.3. Use the Finite Element software (ABAQUS) to simulate the PCC pile group effect by varying the parameters such as the cushion Yong's module, pile length, pile spacing etc.