Evaluation of Pile Spacing Ratio of Stabilizing Piles for Ground Destruction Reduction at the Time of Soft Ground Excavation

In the case of excavating ground backfilled with soft ground, ground destruction occurs owing to the discharge of groundwater from excavated back ground in spite of earth retaining wall. To minimize this, indoor model test was implemented applying stabilizing pile as a solution for ground destruction. The unreinforced case was compared with the reinforced case and the comparison demonstrated that the ratio of the gap in settlement of the two cases is about three to one, which proves the reinforcement effect (Kim, 2014). This study has carried out the evaluation of appropriate pile spacing ratio, according to the confirmed effect of stabilizing pile. In the evaluation test the case with pile spacing ratio of 0.66 (5 stabilizing piles) was compared with that of 0.76 (3 stabilizing piles), and it has been shown that applying stabilizing pile has effect on ground destruction reduction, but may rather work as load when pile spacing ratio is narrower than a certain interval. So it was found that adjustment for appropriate pile spacing ratio is required at the stage of design. This study has shown that the pile spacing ratio is appropriate at around 0.7~0.8, which reduces ground destruction and does not function as the load of excavated back ground.

[1]  Jae-Hong Kim,et al.  Model Test of Stabilizing Measures for Ground Failure Due to Soft Ground Excavation , 2014 .

[2]  Junjie Wu,et al.  A novel optimal plane arrangement of stabilizing piles based on soil arching effect and stability limit for 3D colluvial landslides , 2015 .

[3]  E E Beer,et al.  FORCES INDUCED IN PILES BY UNSYMMETRICAL SURCHARGES ON THE SOIL AROUND THE PILES , 1972 .

[4]  Lee Seung-Ho.  A Study on Slope Safety Factor Variation by Pile Construction Depth and Space , 2005 .

[5]  Cees J. van Westen,et al.  Comparing two methods to estimate lateral force acting on stabilizing piles for a landslide in the Three Gorges Reservoir, China , 2014 .

[6]  R. Peck.  Deep excavations and tunnelling in soft ground , 1969 .

[7]  G. Wayne Clough,et al.  PREDICTION OF MOVEMENTS FOR BRACED CUTS IN CLAY , 1981 .

[8]  Philip C. Lambe,et al.  Design and Performance of Earth Retaining Structures , 1990 .

[9]  G W Clough,et al.  Performance of Tied-Back Walls in Clay , 1974 .

[10]  E. De Beer,et al.  Methods to Estimate Lateral Force Acting on Stabilizing Piles(ディスカッション) , 1977 .

[11]  Ioannis Anastasopoulos,et al.  Slope Stabilizing Piles and Pile-Groups: Parametric Study and Design Insights , 2011 .

[12]  Andrew J. Whittle,et al.  Ground Movement Prediction for Deep Excavations in Soft Clay , 1996 .

[13]  N D Nicu,et al.  FIELD MEASUREMENTS ON INSTRUMENTED PILES UNDER AN OVERPASS ABUTMENT , 1971 .

[14]  Harry G. Poulos,et al.  Pile Response Due to Excavation-Induced Lateral Soil Movement , 1997 .