Abstract: By installing a bending element module dynamic triaxial apparatus and a series of conventional consolidation instruments for indoor testing and referencing the open excavation foundation pit project of the long and big tunnel in western Hangzhou, the hardening small-strain model (HSS) of soil was considered. On this basis, the structural parameter ω of soft clay was introduced, and a modified hardening small-strain (MHSS) model parameter valuing method considering the structure of soft clay was obtained, which could improve the calculation accuracy of deformation within the soil constitutive model and reasonably analyze and determine early warning thresholds for pit deformation in long and big tunnel projects. The proposed research method can make it easier for practical engineering to obtain accurate hardening small-strain model parameters through geological survey reports.

Key words: geotechnical engineering; Hangzhou soft clay; MHSS model; structural parameters; bender element

摘要： 通过加装弯曲元模块动三轴仪、常规固结仪系列的室内试验，参考杭州城西地区长大公路隧道明挖基坑工程中考虑土体小应变硬化模型（HSS），在此基础上引入软黏土的结构性参数ω，获得了考虑软黏土结构性的改进型土体小应变硬化模型（MHSS）参数取值方法。可以提升土体本构模型中变形计算的精度，合理分析并确定长大隧道工程基坑变形预警阈值。该研究方法能够使实际工程更容易通过地质勘测报告获取准确的小应变硬化模型参数。

关键词: 岩土工程；杭州软黏土；MHSS模型；结构性参数；弯曲元