Mixing Composite Foundation Settlement Calculation Method

As a new soil improvement technology, deep-mixing pile has a number of merits. With the construction of a great number of foundation engineering, it gets much wider application. However, application and development of this technology is greatly confined as academic research still lags behind practice. In this dissertation, in order to provide valuable method for analysis of composite ground, emphasis has been put on study of its character and investigation of longitudinal interaction mechanism between soil and pile. Based on experiments the mechanical behaviors of the soil between piles are studied. A more reasonable method computing settlement is presented. Finally, the numerical analyses for single pile and group piles are done with FDM. The main contents are as follows:l.In a practice project, field test is done. The laws of the deformation characteristic in consolidation and the stress ratio of pile-soil are summed up with the monitoring data. It provides reliable basis for application and theoretical research of deep-mixing pile.2. Load transfer behavior of deep-mixing pile is studied. The full-scale field test is done with novel and reliable method. Working characteristics and load transfer characteristics of deep-mixing pile are obtained. Some characteristics of deep-mixing pile are founded. It provides rich and reliable information for studying deep-mixing pile in theory.3.We study the theoretical computation method of the lateral frictional resistance distribution of single pile, form the way of displacement distributes of pile-soil, under some reasonable assumptions, the lateral frictional resistance distributes sustaining axial load formula is derived.4. Considering the longitudinal interaction between soil and single pile, a united method of Mindlin and Boussinesq solution is derived to computer the additional stress and settlement of the foundation. Considering the influencingfactors, we form the simple way to compute the additional stress for the engineering applications.5. The additional stress field of deep-mixing pile composite ground is analyzed with FDM, it explain the distribution characteristics of additional stress and settlement characteristic, and the results confirm and apply the analysis of the united method.