高速公路软土地基处理设计研究

吴承志¹，谢弘帅²

（茂盛国际集团¹，上海同济大学地下建筑与工程系²）

摘要：软土地基处理是影响软土地区高速公路建设周期和建设投资的关键。大量的设计和施工实践经验，使得必须对高速公路软土地基处理规范中的一些规定做深入的思考。本文根据土体的物理性质，提出了软土、软粘土和非软土的完整分界，指出软土地基处理应以压实系数K≥0.85为下界；根据地质勘查报告，将出露的土层分为四大类，设计中应根据四类不同土层采取相应的地基处理方式；设计中总沉降计算受m取值和主固结沉降Sc影响较大，其计算值只供参考，不可作为施工方案选取的唯一标准；主固结沉降中不同计算方法所得结果差异较大，提出计算终结条件考虑以压实系数K≥0.85为标准更合实际且概念明确。文中所提的其他一些原则，在设计中必须予以考虑，以做到所提软基处理方案切实有效、又节省建设投资。

关键词：软土地基、软粘土（过湿土）、非软土、压缩模量、压实系数、主固结沉降

Study of the reinforcement on soft subsoil of freeway

WU Cheng-zhi ，XIE Hong-shuai

Abstract: The reinforcement of soft subsoil is the important factor influencing the construction period and the investment. The experience of design and construction shows that some regulations in the norm must be reconsidered deeply. According to the physical nature, this paper puts forward the division standards among soft soil, soft clay and non-soft soil and advises regarding the K≥0.85 as the control criterion for the reinforcement of soft subsoil. Based on the geological perambulation report, this paper advises to divide the soil into four kinds and adopt different reinforcement measures according to the four kinds of soil. The value of m and Sc influences the general settlement greatly. The results of calculation can’t be looked as the only standards for construction plan. Because there are great difference in different calculation method, this paper puts forward that the concept is distinct by regarding the condition of K≥0.85 as the control criterion in the calculation of the primary consolidation settlement. Other principals advised in this paper should be considered seriously in the design in order to insure the plan reasonable and economize the investment.

Keywords: Soft subsoil, Soft clay； Non-soft soil； Modulus of compressibility； Coefficient of （K）；Primary consolidation