Study On The Effect Of Squeezing Effect On Half-Screwed-Pile Construction In Silty Area

In recent years,high-rise buildings appeared just as bamboo shoots after a spring rain.The natural foundation is often unable to meet the requirements of its bearing capacity.Therefore,pile foundation and composite foundation are widely used in engineering construction.Screw pile is a new type of variable section pile,pile foundation for pile foundation and composite foundation,compared with other bored piles,pile soil,screw has to adapt to the fast construction speed,high bearing capacity,construction noise,construction and environmental protection advantages.In this paper,the compaction effect in the construction of the screw pile is analyzed theoretically.Based on the engineering example in Henan,the finite element simulation of the process of the screw pile is carried out by ABAQUS.Main works in this dissertation are listed as follows:1.The construction technology,construction equipment and quality control points of the screw pile are expounded in detail.The engineering problems of the screw pile in the construction process are discussed and the countermeasures are put forward.2.The analysis of soil disturbance in the construction of screw pile in silty area is carried out.Combined with the engineering characteristics of silt in the construction of soil liquefaction phenomenon may be studied.Based on the previous research results,the calculation theory of soil displacement caused by squeezing effect under ideal condition is discussed,and a simple formula derivation is carried out..3.Based on a specific project in Henan Province,ABAQUS finite element analysis software was used to simulate and analyze the influence of squeezing effect on the soil of the screw pile.The influence law was obtained.Combined with the finite element simulation to analyze the sensitive factors affecting the soil disturbance caused by the squeezing effect of the half-screw pile.Through the horizontal and vertical contrast,it is concluded that the elastic modulus of the soil and the cohesive force are positively correlated with the effect of the squeezing effect on the soil.The friction angle shows a negative correlation.4.Study on the effect of squeezing effect of pile group in screw pile construction.Taking the double pile as the representative to simulate and establish the two-dimensional model analysis,it is concluded that the whole soil displacement of the construction site increases,the soil disturbance is aggravated and the influence range of the squeezing effect increases.Finally,combined with the sensitive factors influencing the squeezing effect,the measures to control the effect of reducing the squeezing effect in the construction of screw pile are put forward,and the concrete scheme is optimized.On the future similar to the subway project has an important reference and guiding significance.