拉压段长度变化对复合锚杆锚固性能影响研究  

Study on the Influence of Length Variation of Tension-Compression Section on Anchorage Performance of Composite Anchor

作　　者：夏凯 张明礼[1] 张鑫 梁二雷 雷兵兵 Xia Kai;Zhang Mingli;Zhang Xin;Liang Erlei;Lei Bingbing(Key Laboratory of Disaster Prevention and Mitigation in Civil Engineering of Gansu Province,Lanzhou University of Technology,Lanzhou 730050,P.R China;China Construction Fourth Engineering Bureau Co.,Ltd.,Guangzhou 510000,P.R.China)

机构地区：[1]兰州理工大学甘肃省土木工程防灾减灾重点实验室,兰州730050 [2]中国建筑第四工程局有限公司,广州510000

出　　处：《地下空间与工程学报》2024年第1期152-161,180,共11页Chinese Journal of Underground Space and Engineering

基　　金：中国科学院"西部青年学者"项目(23JR6KA027);陇原青年创新创业人才(个人)项目(张明礼)。

摘　　要：抗浮是深基坑施工所面临的重要工程问题之一,目前多使用抗浮锚杆平衡地下水对构筑物产生的浮力。但拉力锚杆具有局部应力集中、临界锚固深度浅等问题。因此研究设计了一种新型拉压分散型复合锚杆。通过现场试验,分析复合锚杆拉压段长度变化与锚杆锚固性能相关关系,并与拉力锚杆进行对比。结果表明:复合锚杆可以有效防止锚杆第一界面发生剪切破坏;随着承拉段与承压段长度比值降低(比值分别为5、2、1),锚杆极限承载力逐渐提高,分别为传统拉力型锚杆的1.17倍、1.22倍和1.44倍,且荷载位移曲线陡降性逐渐消失,结构延性更好;一定范围内增加承压段长度,可以更有效地调用锚固段下部土层强度,锚杆临界锚固深度下移,侧摩阻力发挥程度更高。Anti-floating is one of the important engineering problems faced by deep foundation pit construction.At present,anti-floating anchors are often used to balance the buoyancy of groundwater on structures.But the tensile anchor has the problems of local stress concentration and shallow critical anchorage depth.Therefore,a new type of tension-compression dispersed composite bolt was designed.Through the field test,the relationship between the length change of the tension-compression section of the composite bolt and the anchoring performance of the bolt was analyzed and compared with the tensile anchor.The results show that the composite anchor can effectively prevent the shear failure of the first interface of the anchor.With the decrease of the length ratio of the tension section to the compression section(the ratios are 5,2 and 1,respectively),the ultimate bearing capacity of the anchor increases gradually,which are 1.17,1.22 and 1.44 times of the tensile anchor,respectively.The steep drop of the load-displacement curve gradually disappears,and the structural ductility is better.Increasing the length of the bearing section within a certain range can more effectively call the strength of the lower soil layer of the anchorage section,and the critical anchorage depth of the anchor is moved down,finally the side friction resistance is higher.

关 键 词：复合锚杆 承载特性 现场试验 第一界面 荷载位移曲线 侧摩阻力 

分 类 号：TU413.4[建筑科学—岩土工程]