双排桩护岸在高边坡航道“三改二”工程中的应用

Application of double-row piles in upgrading project of high-slope waterway from level three to level two

双排桩具有施工方便、受力条件好、变形小等优点,广泛应用在各类临时工程和永久工程中。本文以某高边坡航道“三改二”工程为例,基于施工过程对双排桩护岸进行有限元分析,探求合理的桩长和桩距,并以此分析航道开挖过程中双排桩位移和弯矩的变化情况。计算结果表明:1)桩长的增加会明显降低双排桩的最大水平位移,但对双排桩最大正、负弯矩影响较小。2)桩距的增加将略微增大双排桩的最大水平位移,但显著增大双排桩最大正、负弯矩。3)综合考虑结构位移、结构内力和工程造价等因素,该工程前、后排桩的桩长均为22.0 m,前、后排桩的桩距分别为1.0和3.0 m。4)随着开挖深度的增大,前、后排桩的最大水平位移和最大正、负弯矩均显著增加。

The double-row piles which have the advantages of convenient construction,good mechanical behavior,small deformation,and are widely used in the various types of temporary and permanent projects.This paper takes the upgrading project of high-slope waterway from level three to level two as an example,performs finite element analysis on the double-row piles based on the construction process,and then explores the reasonable pile length and pile spacing,hereby analyzes the changes in displacement and bending moment of double-row piles during the excavation process of the waterway.The calculation results show that 1)The growth of pile length will significantly reduce the maximum horizontal displacement of double-row piles,but has little effect on the maximum positive and negative bending moments of double-row piles.2)The growth of pile spacing will slightly increase the maximum horizontal displacement of double-row piles,but significantly increases the maximum positive and negative bending moments of double-row piles.3)Taking into account a variety of factors such as structural displacement,structural stress and construction cost,the pile length of front and rear piles is equally determined to be 22.0 m,and the pile spacing of front and rear piles is determined to be 1.0 m and 3.0 m,respectively.4)As the excavation depth increases,the maximum horizontal displacement and maximum positive and negative bending moments of front and rear piles significantly increases.