软土堤岸预应力桩锚支护体系工程特性分析

Engineering Characteristic Analysis of Prestressed Pile Anchor Support System for Soft Soil Embankment

江苏省连云港盐灌船闸下游软土堤岸航道支护工程采用预应力桩锚支护+支护体后侧粉喷桩局部加固的支护体系。采用数值分析法分析不同影响因素对支护体后侧粉喷桩局部加固后堤岸预应力桩锚支护体系变形受力特性的影响。基于现场试验数据,对有限元数值分析模型进行验证,探讨桩径、锚固深度、锚固力及桩体抗弯刚度等因素对桩身变形和弯矩分布规律的影响。结果表明:桩体嵌固深度的增加有效地控制了桩锚支护结构的水平位移和弯矩,随着锚索锚固力的增加,桩锚支护结构的水平位移减小,但弯矩增大;桩径和桩体抗弯刚度变化对支护结构的水平位移和弯矩的影响效果不明显。

The channel levee at the downstream of Yanguan Lock in Jiangsu province was reinforced by pile-anchor retaining structure combined with localized improvement by jet grouting columns.In this paper,finite element numerical analysis was conducted to investigate the effects of localized soil improvement on performance of pile-anchor retaining system in levee over soft soil.The numerical model was calibrated in a comparison between the numerical results and the field measurements.After that influence factors of pile diameter,anchoring depth,anchoring force and width of localized improvement on the force-deformation characteristics of pile-anchor retaining system were explored.The analysis results show that the effect of pile diameter and pile bending stiffness on the horizontal displacement and bending moment of pile-anchor supporting structure is not obvious.However,the increase of pile length can effectively control the horizontal displacement and bending moment of pile-anchor supporting structure.As the anchor force increase,the horizontal displacement decreases but bending moment increases.