Based On The Distributed Optical Fiber Measurement Technology Of H Anti-slide Force Analysis Research

With the rapid development of the western expressway,the difficulty and cost of project management are increasing year by year due to the large-scale and large-scale landslide caused by the deep filling and deep excavation.The traditional single row or multi-row anti-slide piles can not meet many works Deformation and stability requirements,h-type anti-slide pile due to its spatial structure characteristics were raised.Taking the h-type anti-slide pile of a large landslide in Guizhou Province as an example,in order to understand its characteristics of stress deformation and internal force distribution in landslide treatment,this paper adopts the traditional deep slope measurement and advanced BOTDA monitoring technology,Numerical simulation,mechanics theory and other methods combined with engineering examples of the h-type anti-slide pile force analysis of the study.The main results are as follows:(1)This paper briefly introduces the monitoring principle of distributed optical fiber sensing technology and establishes the monitoring system of h-type anti-slide piles.Combined with advanced BOTDA optical fiber testing technology and traditional deep displacement,the h-Strain deformation test,through the displacement and strain feedback,h-type anti-slide pile in the treatment of large landslides when the effect is significant.(2)According to optical fiber measurement technology of h type strain of anti-slide pile the calculation model of the thrust of the landslide on the rear piles is put forward by using the bending moment and the shear force calculated by the mechanical theory to determine the landslide thrust Size and distribution form,the calculation results and the commonly used form there is a big difference,compared to engineering design calculations,that the design conservative.(3)Through the optical fiber monitoring of the pile body strain is proposed to calculate bending moment,shear force,axial stress method.Reinforced concrete material specifications according to the calculation theory,the relationship between the strain and stress,and bending components,etc.,through the inverse calculation of pile body strain pile body internal force,and by using calculation of anti-slide pile axial force and strength of reinforced concrete material standard comparison,analysis and evaluation for anti-slide pile working condition.(4)Using finite element software FLAC3 D numerical calculation model is set up,optimize the h anti-slide pile design,through the analysis of the connecting beams of different length,front row pile anchorage depth,relative stiffness of connecting beam and cantilever length of piles,the influence of h Suggestions for optimization design of piles of h value.It is considered that the optimum design of H anti slide pile structure is that the connection beam is 2~3 times the pile width,the stiffness is 2.5 times EI,and the anchorage depth of the front row piles is 1/3 and 1/3.3 corresponding to the pile length,and the length of the cantilever section is 1/4.