拓宽道路差异沉降的新型处治方式

A new treatment method for differential settlement of widening road

道路拓宽工程中,由于新老路土基存在着模量差,即使采用搅拌桩进行处理,在新老路交接处依然会产生不均匀沉降的问题。针对中山沙港公路实践,提出了一种双层筋网夹水泥土结构处治新老路基拼接处差异沉降的方法,建立新老路土基-桩-筋网夹水泥土结构有限元分析模型,分析不同模量比条件下路基土无处理、新路土基12m桩处理和12m桩加双层筋网夹水泥土结构处理三种情况的路面变形状况。结果表明:新老路土基模量比越小,不均匀沉降量越大;新路土基仅进行搅拌桩处治仍难控制拼接处差异沉降;解决了道路扩宽过程中新老路易出现不均匀沉降的问题。

The differential settlement still appear at the junction of new and old roads when the existed road is widened with mixing piles.A reinforced structure with double-layer reinforcement mesh and cement soil is proposed during the widening practice of Zhongshan Shagang highway.By establishing the finite element analysis model of soil-pile-reinforcement net sandwiched soil-cement structure of new and old roads,the pavement deformation without treatment,12 m pile of new road foundation and 12m pile with double reinforcement net sandwiched soil-cement structure under different modulus ratios were analyzed.It is showed that the smaller the modulus ration of new and old subgrade,the greater the uneven settlement.Controlling the differential settlement at joint only by mixing pile treatment is extremely difficult.This structure is used to alleviate the uneven settlement in the process of road widening.