基于流变效应锚杆柔性支护在基坑中的应用  

Application of flexible reinforcement with anchor in foundation pit based on rheological

作　　者：王军[1] 曹平[1] 曾国柱 林杭[1] 

机构地区：[1]中南大学资源与安全工程学院,湖南长沙410083 [2]广州穗监工程质量安全监测中心,广东广州510150

出　　处：《解放军理工大学学报（自然科学版）》2009年第5期467-471,共5页Journal of PLA University of Science and Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(50774093);高等学校博士学科点专项科研基金资助项目(20060533071)

摘　　要：针对基坑工程预应力锚杆柔性支护的工程特点,依据流变力学理论,提出了一种新的粘弹塑性流变模型,建立了最小锚固锁定荷载的计算式。该模型体现了锚固体和基坑土体的流变效应以及面层、锚杆与基坑壁面的连接特性,并与有限差分程序FLAC3D结合,对锚杆、浆体的受力、安全系数和位移进行了数值计算。根据计算结果和现场监测,得出了预应力锚杆的最小锁定荷载、预应力锚杆筋材应力的不均匀分布和最大轴力位置、浆体剪应力的驼峰分布和面层的剪应变率及加固后坑体位移的分布等有用结论,其结果与现场监测基本吻合,数值计算能较好地反映实际情况,为有效的基坑支护提供了理论依据。Aimed at the characteristics of flexible support of foundation pit with prestressed anchor for civil engineering, rheological mechanics was applied to calculate the designed parameters and to evaluate reinforcement effects. A new viso-elasto-plastic rheological model was estabished with the locked loading formula, which took on the properties of bonding soil, the surrounding soil, the bolts and the excavation surface and so on. The finite difference method （FALC^3D） was applied in the numerical calculation of the anchor, the grount loading, the shear strain rate, the safety factor and the displacement. Based on the calculated results and the on-spot testing, plenty of key parameters on the whole bonged and the prestressed bolt were studied. Finally,the conclusions about the minimum locked loading, the stress and the maximal axial distribution of the prestressed steal, the hump distribution of shear stress on the grount and the displacement of the reinforced foundation pit and so on were drawn. The numerical calculation which agrees with the testing factors, can provide theoretical basis for effective surrport engineerings.

关 键 词：岩土工程 基坑柔性支护 流变 预应力锚杆 

分 类 号：TU443[建筑科学—岩土工程]