黄河下游冲积地层高压旋喷锚索拉拔特性研究  

Study on pull⁃out characteristics of high⁃pressure rotary grouting anchor in alluvial formation of lower Yellow River

作　　者：邵广彪[1,2] 孟超 邢又家 韩健勇 SHAO Guangbiao;MENG Chao;XING Youjia;HAN Jianyong(School of Civil Engineering,Shandong Jianzhu University,Jinan 250100,China;Key Laboratory of Building Structural Retrofitting and Underground Space Engineering(Shandong Jianzhu University),Ministry of Education,Jinan 250101,China;Jinan Kingyue Highway Engineering Company Limited,Jinan 250014,China)

机构地区：[1]山东建筑大学土木工程学院,济南250100 [2]山东建筑大学建筑结构加固改造与地下空间工程教育部重点实验室,济南250101 [3]济南金曰公路工程有限公司,济南250014

出　　处：《建筑结构》2023年第19期40-46,156,共8页Building Structure

基　　金：国家自然科学基金重点项目(52038006)。

摘　　要：为揭示黄河下游冲积地层高压旋喷锚索的拉拔特性,基于济南起步区黄河大道地下快速路基坑工程,选取了两组共8根高压旋喷锚索进行拉拔试验,并利用ABAQUS进行单根高压旋喷锚索拉拔精细化有限元计算。通过现场试验与数值计算结果对比,分析了高压旋喷锚索侧摩阻力和端阻力承载机制,研究了极限抗拔承载力的计算方法。结果表明:随加载荷载增大,高压旋喷锚索锚固段从全长弹性到局部塑性再到局部破坏后达到极限承载力,侧摩阻力峰值由端部向后不断传递,锚固体前段4m的侧摩阻力约占总侧摩阻力的86.9%,锚固段长度可进一步优化;加载期间,高压旋喷锚索端阻力持续增大,达到极限破坏时端阻力承担的荷载约占总荷载的30%,使得其位移增量变化较稳定。考虑端阻力提高效应及施工工艺因素,提出了黄河下游冲积地层高压旋喷锚索极限抗拔力承载力计算公式,通过与其他不同计算方法的对比分析,验证了该计算公式的合理性。In order to reveal the pull-out characteristics of high-pressure rotary grouting anchor in alluvium formation of lower Yellow River,based on the foundation pit project of Yellow River Avenue underground expressway in Jinan starting area,two groups of eight high-pressure rotary grouting anchors were selected for pull-out test,and ABAQUS was used to carry out the fine finite element calculation of single high-pressure rotary grouting anchor pull-out test.By comparing the results of field test and numerical calculation,load bearing mechanism of side friction and end resistance of high-pressure rotary grouting anchor was analyzed and the calculation method of ultimate pull-out bearing capacity was studied.The results show that the anchorage section of high-pressure rotary grouting anchor reaches ultimate bearing capacity from full length elasticity to local plasticity and then local failure,the peak of side friction is continuously move backwards gradually and the anterior 4m of the anchorage body accounts for about 869%of the total side friction,therefore the anchorage body length can be further optimized.During the loading period,the end resistance of high-pressure rotary grouting anchor keeps increasing and accounts for about 30%of the total load at the ultimate failure,which makes the displacement increment change more stable.The effect of end resistance improvement and construction process factors are considered,the calculation formula for calculating the ultimate pull-out resistance of high-pressure rotary grouting anchor in alluvium formation at lower Yellow River was presented and the rationality of the calculation formula is verified by comparative analysis of different methods.

关 键 词：高压旋喷锚索 黄河下游冲积地层 拉拔试验 承载机制 有限元计算 极限抗拔承载力 

分 类 号：TU432[建筑科学—岩土工程]