Method for analyzing influences, caused by beaded-shaped karst, on pile foundation stressed deformation

Abstract

The invention discloses a method for analyzing influences, caused by beaded-shaped karst, on pile foundation stressed deformation. The method comprises the following steps: A, selecting finite element numerical value simulation software; B, establishing an axisymmetric two-dimensional geometric model according to on-site geological researches; C, carrying out grid division, selecting a constitutive model, and setting boundary conditions and material parameters; D, additionally arranging a contact unit between a pile foundation and a stratum; E, killing a pile foundation material unit, and simulating a stress state and settlement deformation of the stratum under the effect of gravity; F, activating the pile foundation material unit and simulating pile foundation construction; G, applying pile foundation top load and simulating the effect of external load; H, discounting an elastic modulus of fillings in a karst cave, and simulating a secondary consolidation settlement process of the soft fillings in the karst cave after disturbance; and I, obtaining stressed deformation results of the stratum and the pile foundation through a post-processing program. The method disclosed in the invention is feasible, simple and convenient to operate and efficient in calculation, has the effect of satisfying the design and construction of pile foundations in karst areas, and has great importance for the design and construction of building pile foundations in the karst areas.

Description

technical field [0001] The invention relates to the technical field of calculation and analysis of architecture and civil engineering, in particular to an analysis method for the influence of beaded karst on the force deformation of pile foundations, which is suitable for the research on the law of the influence of bead karst caves on the force deformation of large bridge pile foundations. Background technique [0002] With the increasing scale of engineering construction, the harm of karst to buildings has attracted more and more attention. The development of karst destroys the integrity of the rock and greatly reduces the stability and strength of the rock. Under the action of other factors such as vibration and additional load, the roof of the cave may collapse and the foundation suddenly sinks, causing damage to the structure. cause heavy losses. [0003] The stability evaluation of bridge pile foundations in karst areas is a very complicated problem, and it has also re...

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Problems solved by technology

Or, due to the existence of the weak interlayer under the bearing layer, the excessive depth of rock entry can only increase the length of the pile body to reach the bearing layer below, which will increase the construction cost

The determination of the reasonable thickness of the bearing layer at the pile tip is also the guarantee for the design success under the complex geological conditions in the karst area. If the thickness of the bearing layer is increased one-sidedly, the pile length is often increased too much to find a suitable bearing layer, resulting in a lot of waste

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