纤维加筋土工程性质研究进展

纤维加筋是一种新型的土体改良技术,是指将分散的纤维丝均匀掺入土体中,达到提高土体的工程力学性能的目的。本文根据国内外近20a来在该领域取得的成果,着重对纤维加筋材料、纤维加筋土的工程性质及加筋机理等方面的研究进展进行了介绍。在纤维加筋材料方面,主要有人工合成纤维和自然纤维两种; 在纤维加筋土工程性质方面,纤维加筋能有效提高土体的抗剪、抗压、抗拉强度和承载力,增加土体的破坏韧性和渗透性,降低膨胀土的胀缩性和裂隙发育程度; 在纤维加筋机理方面,目前主要认为纤维的加筋效果主要取决于纤维-土界面的力学作用,即界面黏聚力和摩擦力。最后,针对目前纤维加筋土的研究不足,提出了今后该领域的研究重点和方向,主要包括: 开发简单可行的纤维土施工器具和工艺、开发更专业的纤维产品和降低纤维成本、开展大尺度模型试验和现场试验、纤维-土界面作用机理研究、纤维加筋土的破坏和失效机理研究、纤维加筋土的力学模型及计算理论研究、纤维加筋土的动力学特性研究等。

ADVANCES IN ENGINEERING PROPERTIES OF FIBER REINFORCED SOIL

Fiber reinforcement is a new concept of soil improvement technique. The discrete fibers are evenly incorporated into the soil mass, which aims at improving the mechanical properties of soil. Based on the achievements at home and abroad for the past 20 years in this field, this paper presents the research progress of fiber reinforcement materials, the engineering properties of fiber reinforced soil and reinforcement mechanisms. Generally, there are two categories of fiber reinforcement materials that can be used, i.e.artificial synthetic fibers and natural fibers. On the engineering properties of fiber reinforced soil, the fiber reinforcement is effective in improving soil shear strength, compressive strength, tensile strength, bearing capacity and cracking resistance, increasing the fracture toughness and permeability of soil, reducing the swelling and shrinkage potential of expansive soil. For the fiber reinforcement mechanism, it is believed that the fiber reinforcement benefit is dominated by the interfacial mechanical interactions between fiber/soil, namely the interfacial bonding and friction force. Finally, the current research limitations in this field are discussed, and some new directions and research topics are proposed for the future work. They are development of specialized apparatus and technologies for fiber/soil mixing, development of more specialized fiber products and lower fiber costs, large-scale model tests and field tests, study on interfacial mechanical interactions between fiber reinforcement and soil, study on failure mechanisms and damage effects of fiber reinforced soil, study on mechanical model and calculation theory of fiber reinforced soil, as well as study on dynamical characteristics of fiber reinforced soil.