Method for predicting subsidence amount of ultra-long pile group by using stress dispersion mode

Abstract

The invention discloses a method for predicting the subsidence amount of an ultra-long pile group by using a stress dispersion mode. The method comprises the following steps that the additional stress of each soil layer in the thickness range of a compressed layer, in which the stress dispersion is considered, of the ultra-long group pile is calculated; the additional stress is compared with early-stage consolidation pressure, a corresponding soil layer compression amount calculation formula is selected according to the comparison result of the additional stress and the early-stage consolidation pressure to carry out compression amount calculation, the compression amount is calculated according to a layerwise summation method, and then the subsidence amount of the ultra-long pile group is predicted. The method has the advantages that influences of soil body stress history such as natural deposition of a soil body and deep foundation pit earthwork on ultra-long pile group subsidence are fully considered, the peripheral area of the pile group serves as a reference, additional stress is calculated from the soil layer where a pile body takes into account stress diffusion, the compression amount is calculated according to the layerwise summation method, the calculation process is simplified, and the process that a complex formula is used for calculation is avoided; the difference between a calculation result and the actually measured subsidence is small, the calculation result does not need any empirical correction, and the method can be conveniently applied to practical engineering.

Description

technical field [0001] The invention belongs to the technical field of geotechnical engineering, and in particular relates to a method for predicting the settlement of super-long pile groups by using a stress diffusion model in consideration of soil stress history. Background technique [0002] At present, there are few studies on the settlement analysis methods of ultra-long pile groups in geotechnical engineering, and the settlement analysis methods of conventional pile foundations are usually referred to. The settlement analysis methods of conventional pile groups are mostly based on the equivalent pier method or the linear superposition method of additional stress caused by the load in the elastic half space, and will not consider the significant compression deformation of the super-long pile group and the load sharing effect of the soil between the piles. The influence of historical factors of soil stress caused by geological causes or foundation pit excavation and unlo...

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Problems solved by technology

The settlement analysis methods of conventional pile groups are mostly based on the equivalent pier method or the linear superposition method of additional stress caused by the load in the elastic half space, and will not consider the significant compression deformation of the super-long pile group and the load sharing effect of the soil between the piles. The influence of historical factors of soil stress caused by geological causes or foundation pit excavation and unloading on the settlement calculation of super-long pile groups is also not considered. The calculated settlement is generally larger than the actual result, and the calculation method is complicated, which is not convenient for engineering application

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