基于弹塑性模型的微型抗滑桩破坏机制研究  

RESEARCH ON FAILURE MECHANISM OF ANTI-SLIDING MICROPILES BASED ON ELASTOPLASTIC MODEL

作　　者：辛建平[1,2] 郑颖人[1,2] 唐晓松[1,2] 

机构地区：[1]后勤工程学院建筑工程系,重庆401311 [2]后勤工程学院岩土力学与地质环境保护重庆市重点实验室,重庆401311

出　　处：《岩石力学与工程学报》2014年第A02期4113-4121,共9页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家重点基础研究发展计划(973)项目(2011CB710606)

摘　　要：强度折减法与有限差分程序FLAC相结合,对岩土混合边坡、岩质边坡和土质边坡中的微型抗滑桩进行数值极限分析以得到其破坏机制。为得到桩体的破坏形态,根据微型桩的特点考虑桩体进入塑性状态,对其采用实体单元和莫尔–库仑理想弹塑性本构模型,分别从桩体单元破坏状态、变形、内力分布这3个方面进行破坏机制的分析,同时得到微型桩加固后边坡的安全系数及坡体的破坏模式。然后进行微型桩加固土质边坡的大型模型试验,并对其进行1∶1的数值模拟,两者所得结果吻合较好,说明此数值计算方法是可靠的,可用于边坡原型的计算。研究结果表明,不同类型边坡微型桩的破坏机制完全不同,岩土混合边坡桩体主要在滑面处和滑面以上分别发生弯剪破坏和弯曲破坏,岩质边坡桩体主要发生滑带处错动引起的剪切破坏,土质边坡桩体主要发生滑带两侧的弯曲破坏。The failure mechanism of micropiles in rock-soil slope,rock slope and soil slope was obtained based on strengthen reduction and the finite difference program FLAC. Solid elements and Mohr-Coulomb ideal elastoplastic model were used for piles on the purpose of getting the failure state. The microplies getting into plastic state based on its mechanical characteristics,then the failure mechanism of micropiles from failure state,deformation and internal force were analyzed. Safety factor and failure mode of slopes reinforced by microplies are obtained. Then a model test of soil slope reinforced by micropiles is compared with its 1∶1 numerical simulation and the results conform to each other. It shows that the numerical simulation method is correct and can be utilized for slope prototype calculation. Results indicate that the failure mechanisms of micropiles in different types of slopes are completely different. For mixed rock and soil slope,bending shear failure in sliding zone and bending failure above sliding zone happens to piles. For rock slope,the failure of piles is mainly shear failure in sliding zone. For soil slope,bending failure of piles happens on both sides of sliding zone.

关 键 词：桩基础 微型桩 破坏机制 数值模拟 模型试验 弹塑性本构模型 三维模型 

分 类 号：TU473[建筑科学—结构工程]