Analysis of Pile Foundation Bearing Capacity for High-rise Building and Beijing Tertiary Strata Engineering Geology Characteristics

In the western district of Beijing,Quaternary gravel sedimentary beneath widespread distribution of Tertiary strata,such this aquifer with nature vulnerable to environmental impact,which have characteristics of water softening obviously,poor disintegration durability and lower flooding saturated uniaxial compressive strength.M and G projects select the Tertiary strata as a pile tip bearing stratum;test data shows that the pile side resistance partly play,and pile tip resistance does not play,which due to the pile construction changes rock environment,and too thick sediment.At the same time,pile side resistance and pile tip resistance are not independent of each other,due to the hole bottom bearing stiffness support of there is a mutual impact mechanism.Based on the analysis of the characteristics of Tertiary strata and test pile data of the M and G projects,then Lize SOHO eventually choose thick layer of Quaternary gravel as pile bearing stratum;through analyzing Lize SOHO test pile data,which indicates that this region Quaternary gravel layer selected as pile bearing stratum could more effectively play pile side and pile tip resistance,then avoids pile construction disturbance to tertiary.The data of engineering pile test further validates that pile foundation pile design is reasonable.