摘要
深厚软土在固结过程中蠕变沉降显著,经典小变形固结假定已经难以适用。提出真空荷载下考虑蠕变的软土三维大变形固结理论,引入软土蠕变指数随预压荷载作用时间及超固结比的非线性变化规律,考虑了土体固结过程中孔隙比、渗透系数等关键指标在竖向和径向的非线性演化特性,建立了打设有排水板的深厚软土在真空荷载下固结控制方程,利用有限差分方法求解。通过天津某地基处理工程现场实测沉降与孔隙水压力数据验证,证实理论可靠性。结果表明:远离排水板处,蠕变指数对沉降量和孔隙水压力值的影响更显著。预压能显著降低施工后的蠕变沉降量,更大的超固结比能降低土体沉降对蠕变指数的敏感度。
The creep settlement in deep soft soil during consolidation is significant,rendering the classical small-strain consolidation theory inadequate.A three-dimensional large-deformation consolidation theory is proposed for soft soil under vacuum loading,accounting for creep.It incorporates the nonlinear variation of the creep index with preloading duration and overconsolidation ratio(OCR),alongside the nonlinear evolution of key parameters such as void ratio and permeability in vertical and radial directions.A governing equation for deep soft soil with drainage boards under vacuum loading is established and solved using the finite difference method.The validation against field-measured settlement and pore water pressure data from a ground treatment project in Tianjin confirms the reliability of the theory.The results show that the creep index exerts a greater influence on settlement and pore water pressure further from the drainage board.Preloading significantly reduces the post-construction creep settlement,while a higher OCR lowers the sensitivity of settlement to the creep index.
作者
周游
郭伟
任宇晓
张齐正
ZHOU You;GUO Wei;REN Yuxiao;ZHANG Qizheng(School of Civil Engineering,Tianjin University,Tianjin 300350,China;State Key Laboratory of Hydraulic Engineering Simulation and Safety,Tianjin University,Tianjin 300350,China)
出处
《岩土工程学报》
北大核心
2025年第S1期191-195,共5页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金项目(52171273,52108335)。
关键词
软土
真空荷载
蠕变行为
大变形固结
soft clay
vacuum loading
creep behavior
large-strain consolidation
