Through analysis on handling methods of three diffe rent ground, demons trate that multiple compound ground can use different pole materials, different construction methods and make full use of bearing capacity of ground soil in ord er to eliminate ground liquefaction as well as meet requirements of bearing capa city of ground.

In the paper,a comprehensive analysis was conducted on design,construction and testing of the immersed tube rammed pile of concrete and soil compaction pile of double compound foundation treatment in the collapsible region through the projects example,and it was analysized that the effect and the existing problems of the mixed foundation treatment in the collapsible region.

Inquiring into the settlement calculation of multi-pile composite foundation;

Reliability analysis of bearing capacity of multi-pile composite foundation;

Laboratory experiment of multi-pile composite foundation of steel pipe column and sand column;

Stress ratio between piles and soils of multi-element composite foundation;

Based on the loading test data of rigid-flexible piles in multi-element composite foundation,the changes of the stress on pile-top and pile-end of rigid and flexible piles with changes of the applied loads,and the load transfer rules of rigid piles is discussed.

The foundation researching the capacity of multi-element composite foundation is very importment for designing.

Testing study on bearing characteristics of multi-type-pile composite foundation;

Field test of multi-type-pile composite foundation;

Application of multi element composite ground in groundwork processing of drainage culvert;

The concept and classification of multi element composite ground are put forward at first,then the computation methods of bearing capacity and settlement,and the test method of multi element composite ground are also presented in this paper.