| 不同布锚方式对锚索抗滑桩受力与变形影响的物理模型试验研究 |
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| 引用本文： | 王贵华,李长冬,贺鑫,张永权,姚文敏,宋成彬,张华伟.不同布锚方式对锚索抗滑桩受力与变形影响的物理模型试验研究[J].地质科技通报,2022,41(6):262-277. |
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| 作者姓名： | 王贵华 李长冬 贺鑫 张永权 姚文敏 宋成彬 张华伟 |
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| 作者单位： | 1.中国地质大学(武汉)工程学院, 武汉 430074 |
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| 基金项目： | 国家重点研发计划课题2017YFC1501304国家自然科学基金优秀青年科学基金项目41922055 |
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| 摘 要： | 锚索抗滑桩是滑坡的主要支护结构之一。目前, 软硬相间地层条件下锚索抗滑桩的受力与变形特征尚缺乏系统研究。以软硬相间地层为地质背景, 基于自主研发的柔性测斜仪和自动加载系统, 构建了锚索抗滑桩加固滑坡物理模型试验系统, 开展了锚索抗滑桩加固滑坡的物理模型试验, 揭示了推力不断增加过程中抗滑桩、锚索和滑体的变形与受力特征, 对比研究了布锚方式对桩-锚受力与变形的影响规律, 通过数值模拟的方法分析了软硬相间地层对锚索抗滑桩的影响机理, 并以双锚点抗滑桩为例进行了理论分析。研究结果表明: ①在滑坡-锚索抗滑桩体系中, 桩身各点位移和滑体深部位移均随桩身深度的增加而减小, 滑体后部位移速率大于中部, 且滑体位移速率大于桩身位移速率; ②单锚点抗滑桩的桩-锚推力分担比经历了4个阶段的变化, 趋于稳定时桩-锚推力分担比约为9∶1, 锚索拉力作用下桩身弯矩呈"S"型分布, 正负弯矩非对称; ③锚固角度越大, 锚索拉力的增速越大, 不同锚固角度对桩身内力值的影响主要体现在受荷段; ④多锚点抗滑桩结构的锚索分担更多的推力, 与单锚点抗滑桩相比, 双锚点与三锚点抗滑桩的最大桩身弯矩分别减小了22.41%和40.55%;⑤与均质地层相比, 软硬相间地层中软、硬岩交界面处基岩应力发生突变, 不同软岩厚度比和桩底是否嵌入硬岩, 均对锚索拉力和桩-岩之间的相互作用有不同程度的影响; 其次, 双锚点抗滑桩内力的理论值与试验结果较为接近。本研究成果可为软硬相间地层中锚索抗滑桩加固滑坡工程的优化设计提供依据。
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| 关 键 词： | 滑坡 软硬相间地层 锚索抗滑桩 模型试验 桩-锚推力分担比 |
| 收稿时间： | 2021-11-18 |
Physical model test on the effect of different anchoring methods on the mechanical and deformation characteristics of anchored slide-resistant piles |
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| Affiliation: | 1.Faculty of Engineering, China University of Geosciences(Wuhan), Wuhan 430074, China2.School of Civil Engineering, Zhenzhou University, Zhenzhou 450001, China |
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| Abstract: | Anchored slide-resistant piles are one of the main supporting structures for landslides. To date, there is still a lack of systematic studies on the characteristics of the mechanics and deformation of anchored slide-resistant piles in weak-hard interbedded strata. This study taking weak-hard interbedded strata as the geological background, based on the self-developed flexible inclinometer and automatic loading system, the test system was constructed. Model tests of landslides reinforced by anchored slide-resistant piles were conducted, and the force and deformation characteristics of piles, anchor cables, and sliding mass were revealed in the process of increasing loading force. The influence of the layout of anchor cables on the force and deformation of the pile-anchor was analyzed. The influence mechanism of the stratum with weak-hard interbedded rock on the anchored slide-resistant piles was analyzed by numerical simulation. In addition, the theoretical analysis was carried out by taking the double-anchored pile as an example. The results show that: ① in the landslide-pile-anchor system, the deep displacement of the pile and sliding mass decreases with increasing pile depth, the growth rate of the rear is greater than that of the middle in the sliding mass, and the growth rate of the sliding mass is greater than that of the pile. ② The thrust sharing ratio of the pile-anchor undergoes four stages, which is approximately 9∶1 when it becomes stable. Meanwhile, the bending moment of the pile is distributed in an "S" shape under the action of the anchor cable tension, and the positive and negative bending moments are asymmetrical. ③ The growth rate of the anchor cable tension increases with the increase in the anchoring angle, and the influence of different anchoring angles on the internal force of the pile is mainly reflected in the loaded section. ④ The multianchored pile structure can share more thrust than the single-anchored pile, and the maximal bending moment values of the double-anchored pile and triple-anchored pile are reduced by 22.41% and 40.55%, respectively. ⑤ Compared with the homogeneous stratum, the stress of the bedrock at the interface between a weak and hard rock in the weak-hard interbedded stratum changes abruptly, and the thickness ratios of the weak rock and whether the pile bottom is embedded in hard rock all affect the axial force of the anchor cable and the pile-rock interaction to varying degrees.Meanwhile, the theoretical value for the internal force of the double-anchored pile is closer to the test result. The study results of this paper can provide evidence for the optimal design of projects for landslides reinforced by anchored slide-resistant piles in weak-hard interbedded strata. |
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