摘要
渤海湾西海岸带地区的路堤多为填方型式,且以滨海盐渍土为主要填料。以滨海盐渍土填筑路堤,须解决土的盐胀、溶陷和吸湿软化带来的强度下降和稳定性降低问题,以进行土的改性或固化处理。为降低工程费用,固化材料应以常规的无机材料为主,辅助少量的高分子材料。为研究滨海盐渍土填筑路堤的力学性能,完成了石灰固化土和石灰+SH固土剂固化土的无侧限抗压强度、劈裂法抗拉强度、三轴抗剪强度和加州承载比等室内试验,同期还进行了固化土的现场碾压试验,检测了碾压固化土的压实度、平整度、回弹弯沉、加州承载比和回弹模量等指标。试验与研究结果显示:(1)石灰固化土和石灰+SH固土剂固化土均满足填筑路堤的强度和变形指标要求,后者的力学性能优于前者;(2)SH固土剂干燥后的胶膜包裹了土颗粒,且在颗粒间形成了抗水的胶结联结,胶丝在土的孔隙内形成了絮状联结网。胶膜和胶丝网共同作用,提高了固化土的强度、抗变形能力和水稳性;(3)2种固化土的现场碾压试验效果都很好,碾压固化土的现场测试结果与固化土的室内试验结果相一致。石灰+SH固土剂固化土的碾压性能和力学指标均满足"公路路基设计规范"的要求,效果良好,这种固化方法适宜在滨海盐渍土地区推广使用。
Road embankments in west coastal area of Bohai gulf are mainly fill embankment.The fill materials are mainly saline soil.When using saline soil for filling,it should be treated by modification and solidification to solve the weaker strength and stability due to the expansion,depression and serious water absorption of saline soil.More inorganic materials and fewer polymer materials are suitable for a reasonable construction budget.Some tests on saline soil with lime and saline soil with lime and SH agent are carried out.The tests include unconfined compression strength,tensile strength,triaxial shear strength,and CBR in laboratory,as well as degree of compaction,flattening degree,rebound deflection,CBR,and rebound modulus in-situ.The test purposes is to study the mechanical properties of solidified saline soils used for highway embankment fillings simultaneously.The test results indicate that(1)Mechanical indices of two solidified soils meet the requirements on highway fillings.The strength of saline soil with lime and SH agent is better than that of saline soil with lime.(2)SH agent brings about anti-water connection between soil particles,and forms lots of the wire-like connecting network in pores after drying.So anti-deformation and strength in air and water of the solidified soil are increased.(3)It is noted that compaction effort in-situ is well.The test results of the solidified soils are corresponding in the condition of laboratory and in-situ.The compaction and mechanical properties of saline soil with lime and SH agent satisfy the requirements of highway specification and are of a suitable treatment measure and have well using objective in the coastal area.
出处
《工程地质学报》
CSCD
北大核心
2011年第3期440-446,共7页
Journal of Engineering Geology
基金
国家自然科学基金项目(40772166)
关键词
固化土
盐渍土
路堤填料
路堤性能
Solidified soil
Saline soil
Embankment fill
Mechanical properties
Soft soil mechanics
Soil treatment