水平-竖向组合加筋地基力学行为的试验研究及细观模拟分析

项目名称： 水平-竖向组合加筋地基力学行为的试验研究及细观模拟分析

项目编号： No.41202215

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 天文学、地球科学

项目作者： 侯娟

作者单位： 上海大学

项目金额： 25万元

中文摘要： 土工材料已经成为继钢材、水泥、木材之后的第四大建筑材料，其在地基中应用的主要目标是高效率、低成本地改善软弱地基的工作性能。水平-竖向三维立体加筋地基的工作性能优于传统水平加筋地基，申请者通过模型试验验证了这一构想。但是，其中的一些力学行为只局限于推测分析，对其认识还不够深入系统；筋-土作用机理和地基破坏模式只局限于宏观观测，还缺乏微观的模拟和佐证；同时缺少预测水平-竖向加筋地基承载力的力学计算模型，使得地基性能与筋材几何参数之间的关系不太明确。本项目拟采用试验测试、离散元数值模拟和理论分析相结合的技术路线，着力解决这些关键问题。一方面为水平-竖向三维立体加筋地基的推广应用提供科学支撑，另一方面探讨加筋地基研究中的新思路和新方法。项目的特色是从具有重要应用前景的工程需求中提炼科学问题，主要的创新点在于将水平-竖向三维立体筋用于开发新概念地基，微观分析其中的关键力学问题并建立相关理论计算模型。

中文关键词： 水平-竖向筋；地基；力学行为；离散元；计算模型

英文摘要： Geosynthetics have been successfully applied in foundations for three decades. Recently, considerable attention has been given to the development of advanced three-dimensional reinforcement. Some model tests have shown that the H-V reinforcement was superior to the traditional strip reinforcement. Comparisons between sand beds reinforced with H-V reinforcement and strip-reinforcement revealed that the H-V reinforcement system behaves more uniformly, carries greater surcharge, and settles less than the equivalent strip reinforcement. The test results also demonstrate that the vertical elements of H-V reinforcement kept the sand from being displaced under the applied load and redistributed the footing load over a wider area, thereby increasing the shear strength of the composite system, which in turn substantially improves the bearing capacity of the H-V reinforced sand bed. However, the failure mode and mechanism of the H-V reinforced soil foundation is not well understood. Meanwhile, there is still a lack of analytical models for estimating the ultimate bearing capacity of H-V reinforced strip footing. Particle Flow Code (PFC), based on the discrete element method (DEM), is a useful method to investigate the soil properties from the micro point of view. By investigating the stress distribution and displacement i

英文关键词： horizontal-vertical reinforcement；foundation；mechanism；discrete element；analytical