摘要
自进式中空注浆锚杆是一种集钻进、注浆、锚固功能于一体的新型锚杆,在地下抗浮设计中采用自进式中空注浆锚杆,可有效解决软弱、破碎、松散岩层中全粘型锚杆常遇到的塌孔、缩径、注浆不饱满等问题。结合工程实际,对岩层破碎带区和非破碎带区分别采用自进式中空注浆锚杆和全粘型锚杆进行抗浮治理。在破碎带区从抗拔承载力、变形特征、注浆压力和注浆量进行对比分析2种锚杆的抗浮效果。试验结果表明,自进式中空注浆锚杆最大拉拔力均达到400 kN,远大于全粘型锚杆的310~328 kN,最大变形量3.6 mm,残余变形量2.5 mm,远小于全粘型锚杆最大变形量7.6 mm和残余变形量5.7 mm;中空锚杆和全粘锚杆的注浆压力分别为1.3 MPa和1.0 MPa,中空锚杆注浆量较全粘锚杆提高约20%,中空锚杆锚固性能、注浆效果和耐久性能均优于全粘型锚杆。自进式中空注浆锚杆可通过施加预应力,形成拉力型预应力中空注浆锚杆。
The self-drilling hollow grouting anchor is a new anchor incorporating functions of drilling,grouting and anchoring. Engineering issues such as collapse,shrinkage and unsaturated grout in soft and fractured rock can be solved effectively by application of such anchor in the underground anti-floating design. The paper carries out practical comparisons between the self-drilling hollow grouting anchor and fully grouted anchor in the fracture zone and non-fracture zone respectively for anti-floating applications. In the fracture zone,the two anchors are comprehensively analysed regarding anti-floating capacity,deformation characteristics,grouting pressure and grout amount. The test results show that the maximum pullout force of the self-drilling hollow grouting anchors is 400 kN,much larger than that of fully grouted anchors with a range of 310 kN-328 kN;the maximum deformation is 3.6 mm and residual deformation is 2.5 mm,much less than 7.6 mm and 5.7 mm of fully grouted anchors. The grouting pressure of hollow anchor and fully grouted anchor are 1.3 MPa and 1.0MPa respectively,while the grout amount of the former is 20% higher than that of the latter. Therefore the anchorage behavior,grouting effects and durability of self-drilling hollow grouting anchor are evidently superior to those of fully grouted anchor. In addition,the self-drilling hollow grouting anchor becomes tensile prestress-typed after applying prestress.
作者
周永明
徐伟斌
华贝
吴能文
ZHOU Yongming;XU Weibin;HUA Bei;WU Nengwen(Zhejiang Prov.Institute of Architectural Design and Research,Hangzhou 310006,China;Zhejiang Hancheng Architectural Design Co.,Ltd.,Yiwu 322000,China)
出处
《结构工程师》
2022年第5期126-132,共7页
Structural Engineers
关键词
地下抗浮设计
自进式中空注浆锚杆
破碎岩层
试验对比分析
预应力
underground anti-floating design
self-drilling hollow grouting anchor
fractured rock
analysis of test results
prestress
