嵌岩抗拔桩承载力评估及其抗浮的优化设计

The evaluation of bearing capacity and the optimization design of anti-floating capacity for forrock-socketed anti-uplift piles

结合工程实践,以高层建筑附建式纯地下室与主体间的沉降差控制为目标,论述嵌岩扩底灌注桩抗拔承载力的合理估算、纯地下室采用桩基应对整体抗浮不足的优化设计方法。工程实践证明,嵌岩扩底桩可显著提高单桩的抗拔承载力,其嵌岩段抗拔极限侧阻力的估算可参照承压嵌岩桩的方法,以岩石单轴饱和抗压强度标准值表达桩的极限侧阻力标准值,并乘以抗拔折减系数来取值。

Targeted at a scientific control of differential settlement between the attached pure basement of high-rise buildings and the main body in engineering projects,the reasonable estimation of the anti-uplift capacity of rock embedded under-reamed cast-in-situ piles and the optimization design schemes for pure basement to improve the overall anti-floating capacity were discussed. The engineering practical results indicate that the rock embedded under-reamed cast-in-situ piles can increase significantly the uplift bearing capacity of single piles. The estimation of ultimate side uplift resistance of the cast-in-situ piles＇ embedded part can refer to the method used in rock-embedded pressure bearing piles. The ultimate side resistance standard value of the piles can be expressed by rock uniaxial saturated anti-compressive strength standard value multiplied by the uplift reduction factor.