Thick Layer Of Soil Bearing Behavior Of Large Diameter Bored Piles In Applied Research

As we know that the function of load properties of super-long bored piles has being studying for a long time. Super-long bored piles have been applied a great deal in lot's of various civil engineerings,especially in the areas of super-thick soft soil,such as Shanghai city and the other cities along the sea in our country, where the soil is of the fourth quaternary and big thickness and bad soil texture .The soft soil is of the effection of outstanding creeping effection, which makes the study of Load transmission more complicate! The dissertation studys from two typical characteristics of super-long bored piles, analyzing respectly the relations between pile' side friction and the soil texture plie's deepth,relative displacement of pile-soil. At first,! discuss respective that the soft soil texture,the relative displacement of pile-soil and the finishtime of single pile that respective distribute to single piles load capacity. At the same time,I emphasize on the subject of the soil texture ,which is analyzed in detail in theory. The second, according to the features of soft soil's creeping, creeping of super-deepth soft soil is imitated with the visco-elasticity model of MAXWELL and the soil layer arounding single pile is divided into two parts, namely, the areas of elasticity and plasticity. The function of the normal stress to the single pile sideface and finishtime of single pile is deduced from the elaso-plasticity thick-cylinder's answer. The third, the single pile is divided into two parts, die sliding part between pile and soil in the pile's upper and the non-sliding part , according to the maximum relative displacement of pile-soil. With the discussment above,the formula are arrived at to accumulate the whole single-pile's side friction correspondingly. At last, the study above is proved to be effective by the example given in the fourth part of the dissertation.