切方边坡悬臂桩土拱效应形成与失效机制数值模拟  

Numerical simulation on soil arching formation and failure mechanism of adjacent cantilever piles in incised slope

作　　者：吕振利[1] 孙金山[2] 左昌群[2] 王梓懿[1] 

机构地区：[1]华侨大学土木工程学院,福建泉州361021 [2]中国地质大学(武汉)岩土钻掘与防护教育部工程研究中心,湖北武汉430074

出　　处：《长安大学学报（自然科学版）》2015年第2期97-106,共10页Journal of Chang’an University(Natural Science Edition)

基　　金：国家自然科学基金项目(41102196);福建省自然科学基金项目(2012J01220);华侨大学科研基金资助项目;湖北省自然科学基金项目(2012FFB06502)

摘　　要：为了分析切方边坡悬臂桩受力特征,运用二维颗粒流方法建立了相应的数值模型,研究了桩间土拱形成的过程及其破坏机制。依据桩后土体的荷载-位移曲线和变形特征,揭示了桩后土拱形成过程的3个阶段以及各阶段土体应力分布和变形的特征。研究结果表明:抗滑桩土拱的形成机制主要依赖于土体微元的荷载传递过程;土拱效应的形成过程受桩土相对位移的控制,且受桩间距的影响较大,而受土体参数的影响较小;抗滑桩土拱效应失效过程的数值模拟显示,土拱失效过程可分为3个阶段,且该过程受贴近桩体的土体的渐进破坏控制。土体强度和桩间距对桩后土体的荷载-位移曲线影响都较为显著。桩距相同时,随着土体强度的提高,桩后土体的极限荷载也越高,但对应的桩土相对位移量却较接近,同时软弱土体土拱效应的失效以'绕流'模式为主,而强度较高土体的土拱效应失效以'滑塌'模式为主;抗滑桩间距越小,桩后土体的峰值土压力越高,所对应的桩土相对位移越大。Based on mechanics analysis of adjacent cantilever piles in incised slope, the twodimensional particle flow numerical models were created. With these models, the forming and failure process of soil arching was investigated. Based on the soil load-displacement curve and the characteristics of deformation, three phases are demonstrated in the process of forming soil arching. And the stress distribution and deformation characteristics of the soil around the piles in different phases are soil arching mainly also analyzed. The research results show that the formation mechanism of depends on the load transfer process of micro soil elements. The forming process of soil arching is controlled by the relative displacement of soil and piles, and numerously influenced by the pile space but less influenced by soil parameters. The numerical simulation results show that the failure process of soil arching could be divided into three phases, too. And, the failure process is controlled by the progressive failure of the soil close to the piles. The soil load-displacement curves are strongly influenced by the soil strength and pile space. With the same pile space, the peak soil pressure become increasing when the soil strength increases however, the relative displacement of soil and piles are very similar. With the weak soil, the soil arching failure process presents the flow model, and with the strong soil, the soil arching failure process presents the collapse model. With the same soil, the peak soil pressure become increasing when the pile space decreases and the relative displacement of soil and piles are become increasing, too. 1 tab, 16 figs, 16 refs.

关 键 词：岩土工程 边坡 抗滑桩 土拱效应 颗粒流法 数值模拟 

分 类 号：TU472[建筑科学—结构工程]