北京市西六环路膨胀土路堑边坡及路基设计实践与研究

北京市西六环路是国家高速公路网的组成部分,路线全长38.28km、全线双向6车道,路基宽度28.5m,于2009年9月建成通车。受现场条件控制,施工过程中,发现局部路基位于膨胀土段。膨胀土因其含有大量亲水矿物,具有遇水膨胀、软化、崩解和失水收缩、开裂的特性,它对各类浅表层轻型工程建设具有特殊的危害作用,被称之为"工程中的癌症"。膨胀土边坡并不多见,设计也无成熟的经验。本文通过分析膨胀土地区公路工程病害的发生机理,以及路基破坏的特点和规律,提出了膨胀土路堑边坡及路基设计的方案。

The Practice and Study of Expansive Soil Road Cutting Slope and Subgrade of the 6th West Ring Road in Beijing

The 6th West Ring Road in Belting is part of the National Highway Network, with total length of 38.28km, two-way six-lane ,28.5 meters wide roadbed throughout, which has been completed in September,2009. In the process of construction, it was found that partial roadbed located in the expansive soil. The expansive soil, which is called＂ cancer of project＂, contains a large number of hydrophilic mineral and will swell when watered and shrink when dried out. It has the special harm to all kinds of shallow-surface layer lightweight engineering construction. The expansive soil slope is infrequent, and so far there isn＇t any mature design experience here. However, a design scheme of expansive soil road cutting slope and subgrade was putted forward in the paper, through analyzing the disease mechanism, characteristics and regularities of roadbed failure in the area of expansive soil.