筋-土剪切带的研究现状与展望

State of the Art and Prospect of Shear Band in Reinforced Soil

在加筋土挡墙等加筋土结构设计中,竖向加筋层间距的取值是很重要的参数,但在现有规范中对此值要求并不明确。根据对加筋机理的分析,加筋剪切带不仅关系到层间距的取值,而且与加筋土的力学特性密切相关。首先论述了加筋土剪切带的形成原因及其形成过程,然后分别从理论分析、室内试验和数值模拟3方面对国内外学者在加筋土剪切带研究方法和研究成果方面进行了综述,发现已有成果中剪切带厚度显著地受试验仪器和试验条件等的影响,并且指出了现阶段研究过程中存在的一些问题。最后,提出了对加筋剪切带未来发展方向的思考和展望,认为对剪切带的判别、剪切带内土体的应力应变状态以及加筋土复合体的力学特性将是今后主要的研究方向。

The vertical reinforcement spacing,which is not clear in present specifications,is an important parameter in the design of reinforced soil retaining wall and reinforced earth structure. According to the mechanism of reinforcement,shear band is concerned with the value of vertical reinforcement spacing,and also is closely related tothe mechanical properties of reinforced soil. In this article,the causes and process of the formation of shear band are discussed,and then the research methods and results are summarized from three aspects including theoretical analysis,laboratory tests and numerical simulation. Results show that the thickness of shear band is affected by test apparatus and test conditions. Furthermore,some problems in current researches are pointed out. Finally,the development direction and prospect of shear band in the future are presented： discrimination of the shear band,the stress-strain state within the soil of shear band,and the mechanics characteristics of composite reinforced soil mass will be the main directions of further research.