高速公路零征地加筋拓宽路堤监测分析

Monitoring and Analysis of Embankment Widening of Expressway by Reinforced Soils without More Land

为掌握高速公路零征地加筋拓宽路堤施工和运营过程中特性,对其进行了系统的监测和分析。监测为期2年,监测项目包括路基侧向水平位移、土压力、孔隙水压力等。监测表明,各监测指标的变化主要发生在拓宽路堤施工期与完工后3个月内,其后各监测指标变化较小;采用粉喷桩处理软土地基时,粉喷桩为刚性桩,桩与桩间土不是协调变形,以粉喷桩为主承受上部荷载。分析结果表明:设计方案和施工方案较好,能保证拓宽工程的变形和稳定性要求;零征地加筋拓宽路堤具有较高的稳定性和安全性;为避免拓宽路基的不均匀沉降导致路面开裂,对于拓宽路基宜采用先进行一段时间的堆载预压,然后再修筑路面的施工方法。

To master features of the expressway during construction and operation, a systematic monitoring and analysis are carried out. Lateral horizontal displacement, earth pressure, pore water pressure are monitored with the monitoring period of two years. Results show that all the indicators for monitoring changes mainly occur during construction of widening embankment and three months after construction. Then, all indicators change little. Cement injection pile which is used to treat the soft soil is rigid piles, the piles and the soil between piles do not co-deform; and the piles withstand the upper load. Monitoring results show that：the recommended structure is safe and can ensure the requirement of deformation and stability for the project. In order to avoid the differential settlement of embankment leading, preloading should be adopted for a period of time prior to the pavement construction for widening embankment.