加筋土技术的研究和应用进展

对加筋土技术的研究和应用进展进行了回顾和总结，对现有加筋土构筑物设计计算理论和方法进行了比较和评述．指出室内、室外试验结合有限元分析方法是推动加筋土技术研究和应用进一步发展的有效手段。     

加筋土技术的应用和理论发展概述

通过阐述加筋土的概念,介绍了加筋材料的发展、加筋土技术应用历史、加筋土理论的研究现状,得出国际国内在加筋土技术的研究和推广应用方面也异常活跃,全国各行业部门的许多工程技术人员也均看好加筋土技术,并在工程实践中不断地研究和探索。     

加筋土技术施工要点及控制措施

总结了加筋土技术的施工控制要点，介绍了加筋土挡土墙和加筋土复合地基在施工过程中的质量保障措施和施工工艺，对类似工程的施工具有一定的参考价值。     

纤维加筋土工程性质国内外研究进展

纤维加筋是一种新型土壤性能改良技术,它是指将土体与纤维均匀地混合,以改善土壤的工程性能。本文凭借国内外学者在纤维加筋土技术、性能及应用方面研究经验,对纤维加筋土的强度特性、变形特性等工程特性及纤维加筋土技术的应用研究进行总结。阐述了近年来国内外纤维加筋土的研究进展,并基于现阶段纤维加筋土的理论及技术研究方面的不足,对今后该领域的研究重点和发展方向进行了展望。     

路基施工中的加筋土技术解析

以加筋土技术为分析对象,在阐述加筋土技术应用意义的同时,选择2018年改造项目资料作为研究背景,深入地探讨了加筋土技术在该项目路基工程中的应用。从应用结果可知,应用加筋土技术后,可提升路基承载力与强度,值得推广使用。     

高填方加筋土路堤的质量保证措施

结合工程实例，介绍了高填方加筋土路堤的施工技术，从路基的设计、科研方案、技术要点等方面进行了论述，提出了高填方加筋土路堤的质量保证措施。     

加筋复合土工作机理初探

对加筋土进行了介绍,研究了加筋复合土的工作机理,分析得出了准粘聚力计算模型及公式,以促进加筋复合土技术的研究,推广加筋土技术的应用。     

加筋土挡土墙的施工技术

本文通过介绍加筋土挡土墙的施工实例，论述了加筋土挡土墙的材料选择及施工技术。     

第四届全国加筋土工程技术研讨会（一号通知）

为了不断完善和提高土工合成材料加筋技术,促进科学和技术的发展,第四届全国加筋土工程技术研讨会将于2009年9月12～14日在青岛召开。本届会议将为全国从事加筋土技术研究和工程实践的学者和工程人员提供一个切磋交流的机会,展示加筋土技术方面的新材料、新理论、新方法与新技术,推动我国加筋土技术在理论、试验与实践方面取得更快的发展。我们热诚欢迎全国从事加筋土技术及相关研究和实践的专家、学者、工程技术人员及研究生踊跃投稿并积极参加会议。     

浅谈加筋土技术原理及在工程中的应用

通过对加筋土和加筋材料的概述,阐述了加筋土技术原理及设计计算方法,介绍了加筋土挡墙、加筋土边坡、加筋土地基等加筋技术的工程应用,以推动我国加筋土技术的发展。     

Limit analysis of reinforced slopes

This paper deals with the plastic limit analysis of reinforced soil slopes. First, the theoretical model of reinforced cohesive soil is presented, then, the formulation of boundary value problems by a method of characteristics described. The presented theory is applied to solve the problem of bearing capacity of both weightless and weighty reinforced slopes. Some results of experiments performed on small-scale slopes reinforced with fabric are presented and compared against theoretical predictions. The results presented show that the plastic model of reinforced soil and the method of characteristics serve as a useful tool in the analysis of reinforced soil structures.     

加筋土挡土墙水平位移研究

视加筋土挡土墙为一粘结重力式挡土墙来考虑,受到墙后土压力作用时会产生水平位移,其大小是加筋土挡土墙墙面水平位移的重要组成部分。本文将加筋土挡土墙墙体等效成各向异性的弹性体,视为L宽度的悬臂梁,当受到墙背水平土压力三角形荷载作用时,分别计算纯弯曲和纯剪切两种情况下的水平位移。通过理论计算与工程实例测试结果比较,验证了该方法的正确性。     

加筋地基土压力测试与机理分析

在素垫层内铺设土工材料加筋后,筋土的界面摩擦作用使加筋垫层的模量提高、应力扩散范围增大,有效发挥下卧土层的承载力、减小地基沉降。通过土工带加筋现场原位试验垫层底的土压力分布测试与结果分析得出：加筋薄垫层（Z/B=0.2）地基垫层底土压力分布是不均匀的,应力集中于基础的边缘,基础中心下应力较小。加筋地基强度和变形与加筋参数有关,通过引入应力扩散系数,分析不同加筋参数下加筋地基的应力扩散能力,研究筋土界面摩擦作用的应力扩散加筋机理,结合工程实际提出太原地区应力设计扩散角取值范围,为加筋地基的设计提供理论依据。     

Visualisation and quantification of geogrid reinforcing effects under strip footing loads using discrete element method

Geogrids have been commonly used in reinforced soil structures to improve their performance. To investigate the geogrid reinforcement mechanisms, discrete element modelling of unreinforced and geogrid reinforced soil foundations and slopes was conducted under surface strip footing loads in this study. For unreinforced and reinforced soil foundations, the numerically obtained footing pressure-settlement relationships were validated by experimental results from the literature. In the numerical modelling of unreinforced and reinforced soil slopes, identical models and micro input parameters to those used in the numerical modelling of unreinforced and reinforced soil foundations were used. The geogrid reinforcing effects under strip footing loads were visualised by the qualitative contact force distributions in the soil structures, as well as the qualitative and quantitative tensile force distributions along the geogrids. In addition, the qualitative displacement distributions of soil particles in the soil structures and the quantitative vertical displacement distributions along soil layers/geogrids also indicated the geogrid reinforcing effects in such practical reinforced soil structures. The discrete element modelling results visualise and quantify the load transfer and spreading behavior in geogrid reinforced soil structures, and it provides researchers with an improved understanding of geogrid reinforcing effects at microscopic scale under strip footing loads.     

Independent Reinforced Soil Structure with Pile Foundation—Piled Geo-Wall: An Experimental Study on the Application to Seismic Measure for Embankment—

Our aim in this study was to achieve an independent reinforced soil structure with pile foundation that can be applied to such structures as earth retaining walls and countermeasures against the collapse of embankments or rockfall impact built on narrow construction sites, such as on slopes. In order to confirm the effectiveness of the application of pile foundation to reinforced soil structures by geogrid for improvement of the lateral resistance of the structure and to investigate the interaction between pile and reinforced soil structure, a dynamic centrifuge model test (25 G) was carried out. Two geogrid reinforced soil, one with piles and one without, were used in a countermeasure to reduce the deformation of a road embankment built on a slope in the event of an earthquake, and the effectiveness of the pile foundation to the reinforced soil structure was considered with regard to it affected the road surface. The details and the results of the dynamic centrifuge model test, as well as the interaction between pile and reinforced soil structure are described, and the effectiveness of the application of pile foundation to reinforced soil structure is discussed in this paper.     

短切玄武岩纤维加筋膨胀土的试验研究

玄武岩纤维是一种新型的纯天然绿色纤维。本文将分散的玄武岩纤维丝掺入膨胀土中,研究玄武岩纤维加筋膨胀土的强度与变形特性。试验中,按纤维含量与干土质量比分别为0.0%,0.2%,0.4%和0.6%的比例配制试样。通过室内试验,研究表明:纤维的增加可抑制膨胀土的胀缩性;增加纤维含量,土的无侧限抗压强度和抗剪强度均有所增大,当纤维含量超过最优加筋量0.4%时,加筋膨胀土的无侧限抗压强度和抗剪强度反而会降低。因此,通过掺加玄武岩纤维增强材料,可以获得强度和韧性更高的纤维膨胀土,为膨胀土性质的改良提供一种可借鉴的方法。     

两种加筋土挡墙的动力特性比较及抗震设计建议

为分析比较条带式和包裹式加筋土挡墙的地震动力响应特征,开展了两种加筋土挡墙模型的大型振动台试验.结合震害调查的结果,发现砌块式加筋土挡墙在地震作用下的破坏模式主要表现为局部砌块的松动变形,很少会出现整体垮塌的情况.相比条带式加筋土挡墙,包裹式加筋土挡墙在地震作用下产生的变形量要小.在相同地震量级作用下,包裹式加筋土挡墙相应部位的水平加速度放大系数要小于条带式加筋土挡墙,但峰值动土压力却要比条带式加筋土挡墙大,这是因为包裹式加筋土挡墙面板在地震作用下的变形量小,对土体的约束能力强所致.因此,在抗震设防区,特别是是高地震烈度区进行加筋土挡墙的选型时,包裹式加筋土挡墙应作为一种优选结构.分析认为加筋土挡墙的抗震设计除了要进行整体稳定性的验算外,还应注重墙体变形量的控制,加筋土挡墙在地震作用下的最大变形量应小于允许的变形量.为维持线路的正常使用,加筋土挡墙的变形指数应控制在4%以内.若验算得到的变形量超出允许值,可采取增大墙后填土的压实度和增加拉筋长度,以及加厚墙体和降低墙体坡率等措施.     

A simplified two-phase macroscopic model for reinforced soils

This paper presents the formulation of a macroscopic model for reinforced soil structures in which the interface is taken into consideration as a rigid-plastic contact. The model is formulated in the framework of a so-called multiphase model recently introduced for reinforced soil masses. The proposed simplified two-phase model can be considered as an optimal solution between extremely simplified perfect bonding model on one hand, and using a third phase for the interface on the other hand, which results in a more complicated and time-consuming model. The introduced platform is implemented in a numerical code. The proposed model is evaluated by simulating (a) the failure of laboratorial plane strain compression tests; (b) the behavior of a 1-g reinforced soil retaining wall model under external loading, and (c) the deformation of a reinforced soil structure under its own weight, which has been analyzed by another homogenization approach including elastoplastic interface model. The results indicate that the deformation of reinforced soil structures can be satisfactorily predicted by the proposed model.     

麦秸秆加筋盐渍土的尺寸效应与制样问题处置

制备均匀且整体性较好的试样是保证室内实验结果可靠的前提条件。提出了两端压实的静力制样法,围绕制样中出现的几个问题,制定了适宜的应对措施。同时完成了不同直径的盐渍土和麦秸秆加筋土试样的抗压强度实验,分析了试样抗压强度的尺寸效应,以及试样直径与加筋条件间的比例关系。结果显示:采用两端压实的静力制样方法制备加筋土试样是可行的;两种试样均存在明显的尺寸效应;由于麦秸秆的加筋作用,使得麦秸秆加筋土不同尺寸试样的抗压强度尺寸效应大于盐渍土的,且其抗压强度的尺寸效应随试样尺寸的增大而越来越明显;适宜加筋长度为0.316倍试样直径,适宜加筋率0.25%。研究结果可为制备合格的加筋土试样提供参考,也有益于在未来的研究中选择更合理的麦秸秆加筋条件。