形状记忆合金式锚杆的提出及抗拔承载力特性分析  

Analysis of working mechanism and mechanical characteristics of shape memory alloy anchor slope supporting structure

作　　者：董建华[1,2] 秦兆贤 何鹏飞[3] Dong Jianhua;Qin Zhaoxian;He Pengfei(Key Laboratory of Disaster Prevention and Mitigation in Civil Engineering of Gansu Province,Lanzhou University of Technology,Lanzhou 730050,China;Western Engineering Research Center of Disaster Mitigation in Civil Engineering of Ministry of Education,Lanzhou University of Technology,Lanzhou 730050,China;School of Science,Lanzhou University of Technology,Lanzhou 730050)

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,甘肃兰州730050 [2]兰州理工大学西部土木工程防灾减灾教育部工程研究中心,甘肃兰州730050 [3]兰州理工大学理学院,甘肃兰州730050

出　　处：《土木工程学报》2023年第4期103-118,共16页China Civil Engineering Journal

基　　金：国家自然科学基金(52178335,51778275);中央引导地方科技发展资金(YDZX20216200001739);甘肃省基础研究创新群体项目(20JR10RA205);甘肃省知识产权局高价值专利培育和转化项目(20ZSCQ034);兰州市十大科技创新项目(2020-2-11)。

摘　　要：针对暴雨、洪水、地震等自然灾害频繁发生而诱发的边坡失稳问题,提出宜用于快速抢险救灾工作的形状记忆合金式锚杆结构,详细阐述其结构组成和技术原理;简化出该结构的抗拔承载力计算模型,基于土体柱孔扩张理论得到扩孔压力和内边界位移关系,基于SMA宏观唯象本构模型,由逆悬臂梁问题的思路求解合金片的扩张力和位移关系,基于合金片与土体的变形协调条件对计算模型进行求解,进而得到锚杆抗拔承载力的计算公式,并依托MATLAB软件编制求解程序;结合算例,使用COMSOL Multiphysics多物理场仿真平台建立有限元模型,对合金片-土体相互作用的力学特性进行仿真分析,结果所得的接触力与理论方法计算的扩张力总体分布趋势相似,验证结构的快锚效果和合金片扩张力理论计算方法的可靠性。算例分析表明:合金片的扩张力主要在其弯曲段增长,合金片厚度越大锚杆抗拔承载力越大;相比传统注浆锚杆,新型锚杆很大程度上缩减了锚固段长度,降低了工程成本。研究成果能够为新型锚杆的设计应用提供理论依据和指导。In view of the slope instability caused by frequent natural disasters such as rainstorm,flood and earthquake,a shape memory alloy(SMA)anchor structure suitable for rapid rescue and disaster relief is proposed.The structural composition and technical principle are described in detail.The calculation model for the uplift bearing capacity analysis of the structure is simplified.Based on the cylindrical cavity expansion theory of soil,the relationship between the expansion pressure and the displacement of the inner boundary is obtained.Based on the SMA macroscopic phenomenological constitutive model and the idea of inverse cantilever beam problem,the relationship between the expanding tension and displacement of the SMA sheet is solved.The two indexes are unified and the calculation model is solved by the deformation coordination conditions between SMA sheet and soil.Then the calculation formula of the uplift bearing capacity of the bolt is obtained,and the program of solution is compiled by MATLAB software.Combined with an example,the finite element model established by using COMSOL multiphysics simulation plaform is used to study the mechanical characteristic of interaction between the SMA sheet and soil.The results of finite element simulation show that the general distribution trend of the contact force is similar to the expansion force calculated by the proposed method,which verifies the quick anchoring effect of the structure and the reliability of the theoretical calculation method of the expansion tension of the SMA sheet.It is also shown that the expansion force of the alloy sheet increases mainly in its bending stage,the larger the thickness of the alloy sheet is,the greater the pull-out bearing capacity is.Compared with the traditional grouting bolt,the new bolt greatly reduces the length of the anchorage section and the engineering cost.The research results can provide theoretical basis and guidance for the design and application of the new shape memory alloy(SMA)anchor structure.

关 键 词：扩体锚杆 形状记忆合金 马氏体正相变 柱孔扩张理论 抗拔承载力 

分 类 号：TU475[建筑科学—结构工程]