Large-Scale Shaking Table Test Of The Liquefiable Ground Treated By CFG Piles Composite Foundation

It is taken as the backdrop that the liquefiable ground of high speed railway treated by CFG piles composite foundation. Some main achievements of this dissertation are included by 1:10 scale modeling shaking table test as folio wings:(1) Based on the comparison of three types of model boxes used in the shaking table test on seismic geotechnical problems at present,including rigid walled boX, flexible walled barrel and laminar shear box, a laminar shear box (Length×breadth×height = 4.0m×l.5m×2.5m) has been designed and developed according to the aims and goals of this research.(2) Based on summarizing the research on the scale principle of modeling shaking table test in Japan,the scale principle of this shaking table test has been designed, moreover 1:10 scale modeling shaking table test has been designed.(3) The shaking table test techniques of the liquefiable ground of high speed railway treated by CFG piles composite foundation are discussed, which can provide common reference to the same kind tests in future.(4) The following regularities have been achieved by analysing the results of the modeling test:①The uniform settlement of the subgrade surface has appeared under each vibrating loading the input acceleration of which is from 35gal to 363gal, and the accumulated settlement is increasing with the input acceleration increasing, which is between 18.2mm and 19.2mm at last.②The excess pore water pressure of foundation increases with the increasing of the input acceleration and the embedded depth , which is up to the most when the input acceleration is 161gal.③The acceleration of subgrade and foundation increases with the increasing of the input acceleration and the distance between the surface of the shaking table and the point of foundation.④ The shear deformation of foundation increases with the increasing of the input acceleration,which of the clay layer is very small under each vibrating loading, and which of the saturated silt is small when the input acceleration is from 35gal and 101gal,but increases obviously when the input acceleration is from 161gal and 463gal. ⑤The strain of each test element of the subgrade and foundaton increases with the increasing of the input acceleration, and which is up to the most at the centerof railway in the bedding and the base course of subgrade bed.