摘要
目前工程中出现大量筋材沿墙高非等长布置的加筋支挡结构,可以在增加结构抗震稳定性的同时减少造价。例如,加筋桥台、在既有边坡上新建加筋土挡墙等。由于当前设计方法主要针对筋材长度等长工况,因而导致对非等长筋材验算分析较少见。为此,采用有限元极限分析方法对地震作用下非等长筋材加筋土挡墙稳定性进行研究。通过对比显示,相较于极限平衡法计算值,有限元极限分析法计算得到的屈服加速度接近振动台模型测试值。参数研究结果表明:(1)筋材长度>0.7H时,长度自下而上增大、自上而下增大的筋材布置将使屈服加速度系数分别增大、减小,其中前者可使屈服加速度系数增大约30%;(2)筋材竖向间距sv/H由0.015增大到0.1时,屈服加速度系数近似线性减小,尤其是当筋材长度自下而上增大时;(3)当筋材布置较疏松(s_(v)/H=0.1)并且填土摩擦角>44°时,应尽量采用筋材长度自下而上增大的方式来提高墙体抗震稳定性;(4)随着填土强度的增大,不同布筋方式时的屈服加速度系数均线性增大,其中当填土摩擦角增大70%时对应的屈服加速度系数平均增大约350%。
At present,many reinforced retaining structures with reinforcement of unequal lengths along the wall height are used in engineering practice,which can improve seismic stability while reducing construction costs.Examples include reinforced abutments and newly constructed reinforced soil retaining walls on existing slopes.However,current design methods mainly focus on scenarios with reinforcement of equal lengths,resulting in limited analysis and verification for reinforcement with unequal lengths.Therefore,this study investigated the seismic stability of reinforced soil retaining walls with reinforcements of unequal lengths using the finite element limit analysis method.Comparative results indicated that the yield acceleration obtained by the finite element limit analysis was close to the shaking table test results compared to the values calculated by the limit equilibrium method.Parametric study results indicated that:(1)when the reinforcement length exceeded 0.7H,a layout with reinforcement length increasing from bottom to top increased the yield acceleration coefficient,while a top-to-bottom increasing layout reduced it.The former could improve the coefficient by approximately 30%.(2)When the vertical reinforcement spacing sv/H increased from 0.015 to 0.1,the yield acceleration coefficient decreased approximately linearly,especially when the reinforcement length increased from bottom to top.(3)When the reinforcement was relatively sparse(s_(v)/H=0.1)and the backfill friction angle exceeded 44°,a bottom-to-top increasing reinforcement layout should be adopted to improve seismic stability.(4)As the backfill strength increased,the yield acceleration coefficient increased linearly across different reinforcement layouts;for example,when the friction angle increased by 70%,the corresponding yield acceleration coefficient increased by about 350%on average.
作者
胡超
梁训美
徐鹏
杨广庆
李婷
HU Chao;LIANG Xunmei;XU Peng;YANG Guangqing;LI Ting(China Railway Eryuan Engineering Group Co.,Ltd.,Chengdu 610031,China;Taian Road Engineering Materials Co.,Ltd.,Taian 271000,China;Shijiazhuang Tiedao University,Shijiazhuang 050043,China)
出处
《铁道标准设计》
北大核心
2025年第7期46-50,58,共6页
Railway Standard Design
基金
国家自然科学基金项目(52108331,52208358)
河北省高等学校科学技术研究项目(QN2021127)。
关键词
加筋土挡墙
稳定性
极限分析
筋材
地震
屈服加速度系数
reinforced soil retaining wall
stability
limit analysis
reinforcement
earthquake
yield acceleration coefficient
