摘要
为了给抗滑桩加固边坡的抗震设计提供参考,对其在地震作用下的三维稳定性进行研究。基于极限分析上限定理,采用修正的拟动力法(MPDM)对水平地震作用下的三维抗滑桩加固边坡的稳定性进行了分析,并推导出边坡安全系数(FS)的表达式。为了提高计算效率,采用遗传算法(GA)计算出安全系数的最小值。将所得研究结果与已有文献成果进行对比,验证了所用方法的有效性。此外,通过参数分析研究了归一化频率(ωH/V_(S))、宽高比(B/H)、水平地震系数(k_(h))、阻尼比D、桩位、桩距等因素对桩加固边坡稳定性的影响。研究结果表明:ωH/V_(S)对桩加固边坡稳定性的影响显著,并决定着D对桩加固边坡稳定性的影响;当桩加固边坡受到与土体固有频率接近的地震波作用时,D对桩加固边坡的稳定性影响非常显著,并且拟动力法会极大地高估桩加固边坡的稳定性;对于远离土体固有频率的地震波,D对桩加固边坡的稳定性影响较小;在一个地震波周期内,地震作用下边坡的FS随地震峰值加速度的增加而减小;水平地震加速度系数a_(hs)的峰值会随着k_(h)的增大和D的减小而增大;当B/H小于5时,三维效应对桩加固边坡的稳定性影响不可忽略;对于给定高度的边坡,k_(h)的增大和D的减小会造成F_(S)的降低以及滑裂面的加深,并且会导致最佳桩位向坡顶方向移动。
To provide a reference for the seismic design of slopes reinforced with stabilizing piles,the 3D stability of piled slopes under seismic effect was investigated.Based on the upper bound theorem of limit analysis,a modified pseudo-dynamic method(MPDM)was employed to study the stability of 3D piled slopes under horizontal seismic effect,and the expression for the factor of safety(F_(S))of piled slopes was also derived.To improve computational efficiency,the genetic algorithm(GA)was used to search for the minimum value of FS.To verify the correctness of the calculation method proposed in this paper,comparisons were made between the calculated result of the proposed method and the solution of published literature.In addition,parametric studies were performed to investigate the effects of the normalized frequency(ωH/V_(S)),the weight-to-height ratio(B/H),the horizontal seismic coefficient(k_(h)),the damping ratio(D),pile location and pile spacing on the stability of piled slopes.From the results,it is found that the magnitude ofωH/V_(S)has a significant effect on the piled slope stability and influences the effect of D on the stability of piled slopes.When piled slopes are subjected to the seismic waves with frequencies that are close to the natural frequency of soil,D has a significant effect on the stability of the piled slopes and the pseudo-dynamic method greatly overestimates the stability of the piled slopes,while for the seismic wave with frequencies that are far from the natural frequency of soil,D has a relatively insignificant effect on the stability of the piled slopes.F_(S)of the slope under seismic effect decreases with the increase in peak seismic acceleration within one seismic wave period.The peak horizontal seismic acceleration ahs increase with increasing k_(h) and decreasing D.The 3D effects on the stability of piled slopes are non-negligible when B/H<5.For a slope with given height,the increase of k_(h)and the decrease of D can result in the decrease of F_(S),the deepening of the critical slip su
作者
李雨浓
赵巍
刘畅
王立伟
LI Yu-nong;ZHAO Wei;LIU Chang;WANG Li-wei(School of Civil Engineering&Mechanics,Yanshan University,Qinhuangdao 066004,Hebei,China;Key Laboratory of Green Construction and Intelligent Maintenance for Civil Engineering of Hebei Province,Yanshan University,Qinhuangdao 066004,Hebei,China)
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2024年第1期44-54,共11页
China Journal of Highway and Transport
基金
国家自然科学基金青年科学基金项目(41807295)
河北省自然科学基金项目(E2023203130)。
关键词
路基工程
抗滑桩加固边坡
极限分析上限定理
三维稳定性
地震作用
修正拟动力法
subgrade engineering
slopes reinforced with stabilizing piles
upper bound theorem of limit analysis
three-dimensional stability
seismic effect
modified pseudo-dynamic method
