Research On Pile-Soil Interaction Mechanism And Failure Mode Of Anti-Slide Piles

With the continuous expansion of large-scale transportation infrastructure,the problem of slope stability has become the focus of engineering and academia,and its anti-sliding reinforcement measures have always been a hot topic in geotechnical engineering research.The use of anti-sliding piles has gradually become the leader among many engineering measures due to its advantages of economy,flexibility,strong anti-sliding ability,short construction period and small disturbance.Due to the complexity and discreteness of soil materials and the unreasonable diversity of the design of pile parameters,the instability mechanism of the slope after reinforcement has become extremely complex,and it is inevitable that different failure mechanisms will occur,resulting in unnecessary economic losses.In the process of studying the slope reinforcement with anti-sliding piles in the academic world,for the pile simulation,due to the particularity of the reinforced concrete material itself,coupled with the advantages of simple elastic constitutive calculation parameters,it is widely used by researchers,and the elastic constitutive is used.The plastic deformation and damage of the pile body will be ignored,which may lead to misjudgment of the safety factor of the pile-slope body.Therefore,it is necessary to clarify the different failure modes of the slope reinforced against sliding piles with different parameters and the influence law of the pile failure mode on the slope stability.Therefore,with the help of the finite difference FLAC^3D software,based on the uncoupled analysis method and the coupled analysis method,the research focuses on the following work:（1）Taking the uncoupled anti-sliding pile reinforced slope model as the research object,the anti-sliding pile analysis model based on the soil displacement response is realized,and the anti-sliding pile reinforced slope model is constructed by changing the sliding surface depth and fixing the pile length.The influence of pile-soil friction interface is discussed and compared with literature data to verify the rationality of the model.Compared with the calculation model,two modeling methods are adopted,and the two modeling methods of changing the pile length to fix the sliding surface depth and changing the sliding surface depth to fix the pile length are considered respectively,pile stiffness,the strength ratio of stable soil and unstable sliding layer and stable layer soil and stiffness ratio,the influence of unstable sliding layer soil displacement on pile displacement,internal force,pile-soil pressure,and single-pile resistance,summarize the influence law of each parameter on the soil failure mode,and finally the failure modes appearing in different parameter ranges are quantitatively given.（2）Aiming at the three-dimensional slope reinforced by group piles,according to the uncoupled analysis method,the influence of soil arching effect between piles is considered,the ratio of the strength and stiffness of the soil above and below the sliding surface,and the influence of the displacement of the sliding soil on the displacement and internal force response of the pile.（3）In order to study the influence of pile damage on safety factor,slope failure mode and pile response,damage constitutive was introduced based on finite-difference three-dimensional slope strength reduction,and the elastic constitutive and damage constitutive simulations of piles were compared.The distribution law of pile-slope system safety factor,slope failure mode,pile displacement,internal force and pile-earth pressure under different pile positions.