Construction Of Long-Large Pile Groups And Large Volume Concrete Bearing Platform In Complicated Geological Conditions

The pile foundation construction of modern bridges, bored piles are employed more and more in bridge piles foundations. Now, bored piles are widely applied on the br idge foundat i ons i n the construct ion complicated geological cond it ions.The quicksand layer area of the Zhujiang Delta al luvial plain In Guangdong province, carried on bored piles construction in such a complicated geological condition, it is very difficult.The paper introduced the construction process of a long-large group of pi les, 2 main piers consisted of 48 pi les with 1.8m diameter and 88m depth, and the consruction technique of large volume concrete bearing platform of 2 main piers.To the construction correlated problems of the long-large bored piles and large volumn concrete bearing platform in the so complicated geological cond i t i ons, as fo11ows were studyed:(1) Based on the study of the data of the bored pile construction in similar geological conditions in abroad and home, considerated present capac i ty of mechanical equipment, const i tuted a rational bored construction plan, and resolved successfully the problem of large group of bored piles construction in complicated geological conditions.(2) In the long-large bored construction, made in time a careful analysis on the problems of bored construction of each pile, and summarized up the experiences, improved the techniques, and settled down effectively the problems of the bored piles construction.(3) Through the construction of long-large piles groups, improved the technology of bridge bored pile construction in complicated geological conditions, such as si It layers and impact on tide change, especially application of the construction machine.(4) Employed the techniques of lower temperature by cooler and double mixed technics, optimized the design of concrete mixture ratio and so forth, accomplished successfully the construction of a largevolume concrete of bearing platform in hot cl imate in southern China, meeted the requirement of construction production, besides, accumulated rich site construction experience.