旋喷锚索在黄土状土层中的应用试验研究  

Experimental study on the application of jet grouting anchor cables in loess soil layer

作　　者：马国辉 董忠级 张吉宏 刘向明 Ma Guohui;Dong Zhongji;Zhang Jihong;Liu Xiangming(Xi′an Survey and Design Research Institute Co.,Ltd.of China Nonferrous Metal Industry,Xi'an 710054,China)

机构地区：[1]中国有色金属工业西安勘察设计研究院有限公司,西安710054

出　　处：《工程勘察》2022年第12期33-38,共6页Geotechnical Investigation & Surveying

摘　　要：为研究黄土状土层中的旋喷锚索承载性状及荷载传递机理,在西安某深基坑中的黄土状土地层中施工不同长度的旋喷锚索,并进行抗拔试验及杆体轴力测试。研究表明:单次喷浆条件下,当喷浆压力达到一定的强度后,切割土体的喷射流强度与土体自身的强度达到平衡状态,增加喷浆压力无法增大锚固体直径,同时也造成了浆液的溢流浪费;旋喷锚索在承载力设计值对应的荷载作用下,位移较小,且处于弹性变形阶段,限制基坑支护体系变形的作用显著;锚索杆体轴力分布不均匀,主要分布在锚固体前1/3段,沿深度方向逐渐减小;旋喷锚索极限破坏时,不是从杆体和水泥土界面处破坏,该处提供的黏结力仍有富余。试验研究成果对类似地层旋喷锚索的设计施工有一定的参考价值。In order to study the bearing behavior and load transfer mechanism of rotary shotcrete anchor cables in loess soil layer,the different lengths of rotary shotcrete anchor cables are constructed in loess soil layer of a deep foundation pit in Xi′an,and the pull-out tests and the rod axial force tests are carried out.The study shows that under the condition of single shotcrete,when the shotcrete pressure reaches certain strength,the jet flow strength of the cutting soil and the strength of the soil itself reach a balance state.Increasing the shotcrete pressure cannot increase the diameter of the anchor,but also cause the overflow waste of the slurry;under the load corresponding to the design value of bearing capacity,the displacement of jet grouting anchor cable is small,and it is in the stage of elastic deformation,which has a significant effect on limiting the deformation of foundation pit support system;the axial force of the anchor rod body is unevenly distributed,mainly distributed in the first 1/3 section of the anchor body,and gradually decreases along the depth direction;the ultimate failure of jet grouting anchor cable is not from the interface between the rod body and cement soil,and the bonding force provided by this interface is still surplus.The experimental study results have a certain reference value for the design and construction of jet grouting anchor cables in similar strata.

关 键 词：旋喷锚索 黄土状土 锚索杆体轴力 

分 类 号：TU432[建筑科学—岩土工程]