| 上硬下软地层中h型桩与滑坡相互作用机理模型试验研究 |
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| 引用本文： | 丰月华,罗晓娟,李俊良,曹泽华,姚文敏,宋成彬.上硬下软地层中h型桩与滑坡相互作用机理模型试验研究[J].地质科技通报,2022,41(6):242-252. |
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| 作者姓名： | 丰月华 罗晓娟 李俊良 曹泽华 姚文敏 宋成彬 |
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| 作者单位： | 1.浙江公路水运工程咨询有限责任公司, 杭州 310006 |
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| 基金项目： | 国家自然科学基金优秀青年科学基金项目41922055浙江省交通运输厅科技计划项目2021023国家自然科学基金项目42107181中国博士后科学基金资助项目2021M702932 |
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| 摘 要： | 组合式抗滑桩是加固大型滑坡的有效防护措施, 但上硬下软等复合地层中h型抗滑桩的加固机理仍有待深入研究。基于一套自主研发的上硬下软地层滑坡-h型抗滑桩物理模型试验装置, 综合应力应变监测、激光测距仪、高速相机与粒子图像测速(PIV)技术研究了上硬下软地层滑坡中h型桩的位移、内力响应规律与滑体变形破坏特征, 揭示了上硬下软地层条件下h型桩与滑坡相互作用机理。研究结果表明, 在坡顶荷载逐渐增加的条件下, h型桩加固的上硬下软地层滑坡的演化阶段可划分为蠕变阶段、匀速变形阶段、加速变形阶段和破坏阶段4个阶段。受连系梁影响, 前排桩与后排桩桩顶位移较小, 应变最大值出现在靠近滑面深度处; 后排桩弯矩呈"S"型分布, 前排桩弯矩呈三角形分布, 负弯矩最大值位于连系梁下方20 cm处。随着硬岩体积分数(φβ)增加, 桩顶位移逐渐减小, 前、后排桩最大弯矩值也逐渐减小, 但硬岩体积分数超过60%后最大弯矩值变化幅度较小。当φβ=20%和40%时, 后排桩土压力总体呈抛物线形式; 当φβ=60%和80%时, 土压力总体呈反"S"型, 且滑面附近出现第二个土压力峰值; 前排桩土压力分布形式均为抛物线型。试验结果可为组合式抗滑桩加固机理研究和设计提供理论支撑。
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| 关 键 词： | 滑坡 h型抗滑桩 上硬下软地层 PIV技术 物理模型试验 |
| 收稿时间： | 2022-07-04 |
Physical model tests on the interaction of h-type stabilizing piles and landslides in bedrock with upper hard and lower weak strata |
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| Affiliation: | 1.Zhejiang Highway & Water Transportation Engineering Co. Ltd., Hangzhou 310006, China2.Faculty of Engineering, China University of Geosciences(Wuhan), Wuhan 430074, China3.School of Civil Engineering, Zhengzhou University, Zhengzhou 450001, China |
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| Abstract: | Combined stabilizing piles are an effective measure to reinforce large-scale landslides with complex strata. However, the reinforcement mechanism of h-type stabilizing piles in composite strata, such as strata with upper hard and lower weak bedrock, still needs to be studied in depth. Based on a set of self-developed physical devices for landslide-h-type stabilizing piles in bedrock with upper hard and lower weak strata, monitoring of stress and strain, laser range finder, high speed camera, and particle image velocimetry (PIV) techniques were adopted to study the internal forces and displacement of h-type stabilizing piles in landslides bedrock with upper hard and lower weak strata and the deformation characteristics of landslides, through which the interaction mechanism between h-type anti-sliding piles and landslides were revealed. The results showed that under the loading at the tope of the landslide, the h-type stabilizing pile reinforced landslide exhibited progressive failure characterized by four stages of creep, constant-speed deformation, accelerated deformation, and failure. Influenced by the beam, the displacement of the pile head and front and rear piles is small, but the piles have the maximum strain near the sliding mass. The bending moment of the rear piles showed an "S" type distribution curve, while that of the front piles showed a triangular distribution curve, and the maximum negative bending moment occurred at a depth of 20 cm below the beam. With the increase in the volume content of the hard stratum (φβ), the displacement of the pile head gradually decreased, and the maximum bending moment of the front and rear piles gradually decreased and tended to be stable as φβ exceeded 60%. When φβ was 20% and 40%, the soil pressure behind the rear piles showed a parabolic distribution curve; when φβ was 60% and 80%, it changed to the reverse "S" distribution curve, and the second maximum value occurred near the sliding surface. The soil pressure behind the front piles showed a parabolic distribution type versus the change of φβ. The results of this study can provide a theoretical reference for understanding the reinforcement mechanisms and design theories of combined stabilizing piles. |
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