气泡混合轻质土路基在陕北淤地坝地基中的应用研究

Application and Study of Bubble-mixed Light Soil Subgrade in Warp Land Dam in Shaanxi Northern Region

针对气泡混合轻质土路基的成套设计、施工和质量控制等,在延安~延川高速公路淤地坝地质条件下选择试验段,并对其应用效果进行了监测试验研究。设计了淤地坝路段气泡混合轻质土的断面结构形式及配合比,并确定了湿容重和无侧限抗压强度的设计值;施工过程中严格控制气泡混合轻质土的湿容重和流动度;施工完成后对气泡混合轻质土的力学性能、土压力大小以及路基沉降量进行监测。结果表明：在陕北淤地坝地质环境下（地基承载力约为100kPa）,应用气泡混合轻质土可以直接进行路基换填,其强度及变形能力均能满足使用要求。对原有地基只需进行简单的整平、碾压处理,无需再对淤地坝地基进行相关处理,且沉降监测结果发现路基和地基均未出现显著沉降。

A complete set of processing of bubble-mixed light soil subgrade filling design, construction and quality control are developed and investigated for warp land dams subgrade for the Yan＇an to Yanchuan Expressway. Test road sections is selected and monitoring and study are made to the application result. The cross section structure and the mixture ratio of bubble-mixed light soil are designed, and the design value for wet bulk density and unconfined compression strength are determined; the wet bulk density and fluidity of bubble-mixed light soil in experiment are strictly controlled; the mechanical properties, earth pressure and subgrade settlement are detected after test. The results shows that under the geological circumstance of warp land dams with lOOkPa foundation bearing capacity in Shaanxi northern area, the bubble-mixed light soil could be directly filled into subgrade, only need make simple levelling and rolling for the original foundation and no need to conduct treatment to the dam, and no significant settlement emerges in the subgrade and foundation.