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微型抗滑桩单桩设计计算模型及算法研究 总被引:1,自引:0,他引:1
考虑微型桩与周围岩土体间摩擦力的作用,提出了一种新的微型抗滑桩单桩设计计算模型,并给出了具体算法。由微型桩加固滑坡体的变形特点,分析微型桩与岩土体之间的相互作用机制,将微型桩与周围岩土体的摩擦作用引入其受力分析中;根据微型桩上各部分受力特点的不同,将微型桩分成上部摩擦受拉段、中部滑坡推力作用段和下部锚固段3段进行分析,推导了微型桩总的变形控制方程及各分段的变形控制方程;采用初参数法对控制方程进行求解,得到了微型抗滑桩上的内力分布及变形规律。计算结果表明,在滑坡推力作用下,微型桩的变形主要发生在滑面附近及以上桩段,滑面附近桩段将产生较大的内力和弯曲变形,受拉段弯曲变形较小,近似水平移动;桩与岩土体间的摩擦力是微型桩与周围岩土体相互作用的重要组成部分,摩擦力的作用能显著减小微型桩的弯曲变形,有效控制滑坡体的位移。 相似文献
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Zhaoyu Wang 《Marine Georesources & Geotechnology》2013,31(1):52-62
This paper presents a numerical model of the seismic behavior for the embankment constructed on micropile composite foundation. The effect of micropiles on soil reinforcement under static and seismic loading was studied. Embankments on the untreated and treated soil by micropiles were numerically simulated using an axisymmetric elastoplastic large deformation finite-element analysis code. The displacement caused by embankment static loading and acceleration of the embankment caused by seismic loading were calculated and compared. It was shown that micropiles can greatly reduce the settlement of the embankment and mitigate seismic response of the embankment. The main objective of this paper is to present a numerical model and to investigate the seismic behavior of micropile foundations subjected to seismic loading. A series of numerical simulations and parametric studies are presented. 相似文献
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The in-situ application of micropiles has gradually increased in limited spaces of downtown areas because the micropile has various advantages, such as low vibration and noise and compact machine size. In this study, model tests were carried out to understand the reinforcement effect induced by the mechanical interaction between the micropile and soil. The micropiles were installed in the soil adjacent to footings. Factors such as reinforced range (W) with piles, spacing (S) between piles, the installed angle (θ) of piles, and pile length (L) were considered variables in the tests. The reinforced angle (θ) was a more critical factor than the others for restraining the settlement and increasing soil stiffness in the model test results. The reinforcement effect rapidly increased around the reinforced range (W) of 2B (B: the width of a footing), the reinforced angle (θ) of 45 ~ 75°, and the pile length (L) of 3B. Based on the results of the experimental analyses, the purpose of this study is to improve the reinforcement efficiency of micropiles by recommending the most effective pattern and design method for installing them. 相似文献
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可液化场地微型桩的地震响应分析是确保工程安全和优化抗震设计的前提。应用动态离心机试验和三维有效应力数值分析方法,研究了微型单桩桩台的侧向变形和加速度、不同埋深桩身弯矩、可液化场地的加速度及超孔隙水压力等响应特征。首先开展了相对密实度为57%饱和土层、输入波是频率为1 Hz和峰值加速度为1.516 m/s2正弦波的微型桩40 g动态地震响应离心机试验,进而应用基于多重剪切机构塑性模型和液化前缘状态面概念的三维有效应力分析方法,反演了试验结果,并进行了对比分析,结果表明,数值模拟与离心机试验结果吻合,液化场地特性控制着建于其中微型桩的地震响应特征,微型桩桩台的水平变形和残余变形可达78、30 mm,桩身最大弯矩和最大残余弯矩呈现向桩身底部迁移特点,同时表明,基于动态土工离心机试验和数值分析相结合的研究方法,分析可液化场地微型桩地震响应特性是有效可行的,研究结论为可液化场地微型桩的抗震设计提供了可靠的依据和参考。 相似文献
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为研究桩心配筋微型桩抗滑特性,进行了滑坡微型桩抗滑特性大型物理模型试验.试验结果可得出,桩心配筋微型桩在加载过程中,各排桩同时受力;滑坡推力对桩心配筋微型桩的影响范围为滑面上下各20倍桩径的范围内;桩心配筋微型桩在抗滑工程中主要是受弯破坏,易破坏点为滑面上下3倍桩径处;微型桩群桩的破坏过程是从迎滑第一排桩开始;微型桩能有效提高滑坡体的稳定系数. 相似文献
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注浆微型桩加固软土地基的机理与设计计算 总被引:3,自引:0,他引:3
注浆微型桩复合地基是由桩间改良后的土与注浆微型桩桩体组成的人工地基。从注浆微型桩加固地基的机理与设计计算两个方面进行了分析,并提出了其加固地基的机理及设计与计算的半理论、半经验公式 相似文献