| This paper researched on working properties of the compositefoundation with and without lateral constrain rammed soil-cement pilesunder cyclic load，through the method of large scaled model tests andnumerical simulation combined，carried out with the support of theNational Science Foundation “Researched on Working Properties ofRammed Soil-cement Tapered Piles and Geocell Reinforced CompositeFoundation under cyclic load，came to the following conclusions.（1）Large-scale indoor model tests of composite foundation rammedsoil-cement piles under cyclic load are performed, researched changingregularity of composite foundation settlement under different cyclic loadtimes. The results of model tests show that there are critical cyclic loadratio and critical load times of composite foundation rammed soil-cementpiles under cyclic loading. The relation between composite foundationsettlement and cyclic load times is nearly linear when load ratio is smallerthan critical cyclic load ratio at the same time the number of times is notachieve critical load times or load ratio is bigger than critical cyclic loadratio.（2）Based on the test results, researched changing regularity of pile-soilstress ratio. The research result shows that the more load ratio would lead tobigger pile-soil stress ratio. Pile-soil stress ratio would reduce with loadtimes added, but pile-soil stress ratio will remain unchanged when loadtimes is over critical load times.（3）Based on the test results,researched changing regularity of stress inpile. The research result shows that stress in pile will increase with cyclicload times added. The most stress in pile is not at the top of pile, it islocated at the0.25-0.3time pile length.（4）Large-scale indoor model comparative tests of the compositefoundation with and without lateral constrain rammed soil-cement pilesunder cyclic loading are performed. Based on the comparative test results,influence of lateral constrain on the working character of the compositefoundation is analyzed. The research result shows that lateral constrain can improve load ratio of composite foundation. Lateral constrain can improvethe ability to resist deformation of composite foundation. It has good effectto limit deformation of soft soil. It also has good effect to enhance carryingcapacity of composite foundation（5）Three dimension numerical model of with and without lateralconstrain rammed soil-cement piles under cyclic loading was set up byFLAC3D simulation software. The rationality and reliability of model wasverified by the results of numerical simulation compared to model test. |
