Abstract
A method of reflecting the strength of composite ground formed by deep mixing on horizontal resistance of piles was put into practice. In this design method, the necessary area of ground improvement was set as the area raised to the working gradient of passive earth pressure from the depth of characteristic length of piles. And the horizontal subgrade reaction of piles was introduced from the modulus of deformation of composite ground. The same horizontal resistance of pile as the design was obtained from on-site horizontal pile loading test in composite ground, which supported the reliability of the above process. It revealed that the application of this method to the design of abutment foundation caused much reduction of cost compared with to the current method.
