高速公路拓建工程雨季路床处理技术经济分析

Technological and Economic Analysis of Subgrade Treatment under Rainy Season for Expressway Widening

根据雨季高速公路拓建工程的特点，研究了3种路床处理措施的技术经济性。基于弯沉指标及（或）压实度指标，若遇降雨，级配碎石方案无法满足设计要求，即级配碎石层实测弯沉大于设计弯沉，且容易在雨季施工中积水；水泥稳定土方案则均匀性难以保证，同时无法满足下雨天气施工质量要求；水泥稳定级配碎石方案的处理层顶面实测弯沉及压实度均可基本满足设计要求，但造价较高。为此，通过理论计算及经济分析，推荐了技术经济可行的处理方案。其中，2％～4％水泥剂量的稳定碎石基本可满足各种类型的路面结构设计要求；8％水泥稳定土造价较低，若能够有效地解决针对扩建工程特点的施工工艺问题可考虑优先使用：

In the light of traits of expressway widening engineering in rainy days, the technological and economic characteristics of three types of subgrade treatment are investigated. Based on deflection and/or compactness indexes, if it rains, the graveling scheme will not fit for design requirements, namely, deflection testing values of gravel layer are larger than design value and for the gravel layer it is easy to deposit water in rainy season; the uniformity characteristic of cement treated soil cannot be ensured, and its construction quality cannot be guaranteed in rainy days. Deflection and compactness testing values of cement treated gravel layer can fit for design requirements, but its cost is higher than that of others.Therefore, some possible treatment methods are suggested by technological and economical analysis and some feasible treatments are recommended.Treated gravel admixed with 2% - 4% cement can basically fulfill design requirements of different pavement structures in the study; if the construction technology of cement treated soil can be solved, treated soil admixed with 8% cement can be used in expressway widening engineering.