| 黄土地区抗滑桩嵌固段桩前被动土拱形成演化过程试验 |
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| 引用本文： | 任翔,罗丽娟,李芳涛,潘瑞,刘龙,穆桐. 黄土地区抗滑桩嵌固段桩前被动土拱形成演化过程试验[J]. 中国公路学报, 2022, 35(11): 86-96. DOI: 10.19721/j.cnki.1001-7372.2022.11.009 |
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| 作者姓名： | 任翔 罗丽娟 李芳涛 潘瑞 刘龙 穆桐 |
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| 作者单位： | 1. 长安大学 建筑工程学院, 陕西 西安 710061;2. 长安大学 地下结构与工程研究所, 陕西 西安 710061 |
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| 基金项目： | 国家自然科学基金项目（41877285）;国家自然科学基金重大专项（41941019）;中央高校基本科研业务费专项资金项目（300102289201,300102281724） |
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| 摘 要： | 抗滑桩是大型交通基础设施中稳定边坡和治理滑坡的主要手段之一,嵌固段桩前被动土拱效应是影响抗滑桩水平承载力的重要因素,被动土拱的形成演化过程是抗滑桩水平抗力调整的关键。通过几何缩尺比例为1∶15的抗滑桩物理模型试验,对桩前被动土拱的形成演化过程进行了探究。根据抗滑桩桩前被动土拱和模型试验系统的对称性,自主设计土压力传感器的布设方案,以保证在试验过程中对桩前土体各测点的x和y方向土压力分布规律进行实时采集;采用千斤顶对模型桩施加水平荷载,对加载过程中抗滑桩嵌固段桩身弯矩、桩前土压力及桩前土体应力变化规律进行了分析。绘制桩前土体应力云图并对桩前被动土拱拱轴线进行了拟合,同时采用数值模拟方法进行对照分析,以揭示桩前被动土拱的演化过程。结果表明：①桩身弯矩和桩前接触土压力均在嵌固点下4倍桩宽处附近出现极大值,后随埋深逐渐减小;②桩前被动土拱是由相邻桩对桩前土体的相互作用使主应力发生偏转而逐步形成的,其演化过程可分为初步形成阶段、承载阶段和破坏阶段;③桩前被动土拱拱轴线呈抛物线形式,随埋深逐渐增大形成被动土拱所需桩顶位移随之增大;④同一埋深处桩前被动土拱矢跨比随桩顶位移增加而逐渐变大,在承载阶段土拱矢跨比随埋深逐步减小。
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| 关 键 词： | 道路工程 演化过程 模型试验 桩前被动土拱 抗滑桩 嵌固段 矢跨比 |
| 收稿时间： | 2022-01-29 |
Experimental Study on the Evolution of Passive Soil Arch in Front of Antislide Piles in Loess Area |
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| REN Xiang,LUO Li-juan,LI Fang-tao,PAN Rui,LIU Long,MU Tong. Experimental Study on the Evolution of Passive Soil Arch in Front of Antislide Piles in Loess Area[J]. China Journal of Highway and Transport, 2022, 35(11): 86-96. DOI: 10.19721/j.cnki.1001-7372.2022.11.009 |
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| Authors: | REN Xiang LUO Li-juan LI Fang-tao PAN Rui LIU Long MU Tong |
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| Affiliation: | 1. School of Civil Engineering, Chang'an University, Xi'an 710064, Shaanxi, China;2. Institute of Underground Structure and Engineering, Chang'an University, Xi'an 710061, Shaanxi, China |
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| Abstract: | Using antislide piles is a primary method for slope stabilization and landslide prevention in large-scale transportation infrastructures. The passive soil arch in front of the embedded portion of the piles is critical in determining the bearing capability of the antislide piles. The formation and growth of a passive soil arch are critical for adjusting the horizontal resistance of the antislide pile. They were studied using a physical model test with a geometric scale of 1:15. Based on the symmetry of the passive soil arch in front of the antislide pile and the model test system, a layout scheme for soil pressure sensors was designed independently to ensure the real-time acquisition of the soil pressure distribution in the x- and y-directions at each measuring point in front of the piles. Jacks were used to apply a horizontal load to the model piles. The variation laws of the pile moment, soil pressure, and soil stress in the embedded section of the antislide piles in the loading process were studied. A stress nephogram of the soil in front of the pile was drawn, and the axis of the passive soil arch in front of the pile was fitted. Simultaneously, a numerical simulation approach was employed for comparison analysis to determine the evolution process of the passive soil arch in front of the pile. The results are as follows. ① The bending moment of the piles and the earth pressure in front of the piles have maximum values around four times the pile width under the embedded point and then decrease gradually with the buried depth. ② A passive soil arch in front of the piles forms gradually because of the principal stress deflection caused by the interaction between adjacent piles, and its evolution process can be divided into the initial formation, bearing, and failure stages. ③ The arch axis of the passive soil arch in front of the pile is parabolic, and the displacement of the pile top increases with the buried depth when a passive soil arch forms. ④ The rise-span ratio of the passive soil arch in front of the piles increases gradually with an increase in the pile top displacement, and the rise-span ratio of the soil arch decreases gradually with the buried depth in the loading stage. |
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| Keywords: | road engineering evolution process model test passive earth arch in front of piles anti-slide pile embedded section rise-span ratio |
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