摘要
数值分析方法能够同时考虑抗滑桩的受力行为及加固边坡稳定性,是研究抗滑桩加固边坡稳定性的重要手段。但在数值模拟计算中,尚未形成一种建模易、精度高和计算快的抗滑桩数值模拟模型。因此,提出一种复合单元抗滑桩模型,基于该模型系统研究抗滑桩顶部自由和固定约束条件下,不同桩位、间距等设计参数对抗滑桩加固边坡效果的影响以及抗滑桩潜在失效模式,研究结果表明,复合单元抗滑桩模型可以真实地模拟桩的力学性能,计算精度高且计算结果不受单元网格疏密的影响。抗滑桩布置在边坡中部时,加固边坡安全系数最大,越靠近边坡两端,加固边坡安全系数越小。当桩间距S≤3D时,边坡潜在滑面被分为两个独立部分,桩间土形成明显应力拱,当桩间距S≥4D时,桩间中心土体塑性剪切带完全贯通,桩间土体形成反向应力拱。桩顶自由和固定约束时,抗滑桩分别布置在边坡中部(Lx/L=0.5)和边坡中下部(Lx/L=0.3)时,抗滑桩易发生弯曲破坏。研究结果对抗滑桩加固边坡工程设计具有指导意义。
The numerical analysis method is an important method to study the stability of the slope reinforced with anti-slide pile, which can take both the mechanical behavior of the anti-slide pile and the stability of the slope into consideration at the same time. However,in the previous numerical simulation,it is hard to find a numerical model of the anti-slide pile with easy modeling,high precision and low time cost.Therefore,an anti-slide pile model coupled with the composite solid-structural element is proposed in this study.Based on this model,the influence of design parameters such as pile location and space on the stability of slope reinforced by composite anti-slide pile are studied under the free and fixed constraints of anti-slide pile top.Besides,the potential failure modes of anti-slide pile is also studied.The results show that the proposed model can realistically simulate the mechanical properties of the pile with a high calculation accuracy,and the calculation results are independent on the mesh density.When the anti-slide pile is arranged in the middle of the slope,the safety factor of the reinforced slope reaches to a maximum value.The closer to both ends of the slope,the smaller the safety factor of the reinforced slope.When the pile space is less than 3D,the potential sliding surface of the slope is divided into two independent parts,and the soil between the piles forms an obvious stress arch.When the pile space is larger than 4D,the plastic shear zone of the center soil between the piles completely penetrates,and the soil between the piles forms the reverse stress arch.When the anti-sliding piles are arranged in the middle ( Lx/L=0.5) and in the lower part of the slope (Lx/L=0.3) with the free and fixed constraints in pile top,respectively,the anti-sliding pile is easy to bend and damage.The results have guiding significance for the engineering design of slope reinforced with anti-slide pile.
作者
陈冲
王卫
吕华永
CHEN Chong;WANG Wei;LU Hua-yong(Department of Engineering Physics,Tsinghua University,Beijing 100084,China;School of Civil Engineering,Tsinghua University,Beijing 100084,China;School of Architecture and Engineering,Shangqiu Normal University,Shangqiu,Henan 476000,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2019年第8期3207-3217,共11页
Rock and Soil Mechanics
基金
国家重点研发计划(No.2018YFC1507805)~~
关键词
抗滑桩
边坡
稳定性
桩位
间距
失效判别
anti-slide pile
slope
stability
pile location
pile space
failure discrimination
