Experimental Study on the Bearing Mechanisms of Rock-socketed Piles in Soft Rock Based on Micro X-ray CT Analysis
Experimental Study on the Bearing Mechanisms of Rock-socketed Piles in Soft Rock Based on Micro X-ray CT Analysis
复制标题
基于显微X射线CT分析的软岩嵌岩桩承载机理试验研究
DOI：
10.1007/s00603-020-02121-3
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发表时间：
2020-04
影响因子：
6.2
通讯作者：
Xu Feng
中科院分区：
文献类型：
--
作者：
Xu Jiang;Haque Asadul;Gong Weiming;Gamage Ranjith Pathegama;Dai Guoliang;Zhang Qi;Xu Feng
非破坏性成像技术使人们能够研究各种岩土工程问题的物理模型中的破坏机制。本文提出了一种创新的实验方法，利用微型X射线计算机层析成像(CT)和室内实验装置，研究了人工合成三角形凹凸体中的模型桩在压缩荷载作用下的承载机理。通过对模型桩荷载试验的X射线CT图像分析，揭示了岩石凹凸体与桩之间的四个滑动剪切阶段，并通过示意图解释了每个阶段的相互作用机理。此外，模型桩端以下的受压区分布符合基于球形空洞扩展理论的球形破坏模式。直观地支持了球面空腔扩张理论在软岩嵌岩桩端载计算中的适用性。此外，在滑动和初始局部剪切过程中，围岩的变形以柱状空洞膨胀为主，在岩石内部产生径向裂纹。利用圆柱孔扩张理论和Hoek-Brown破坏准则讨论了井壁岩石的应力路径和围岩中裂纹的形成。到目前为止，这些径向裂缝对钻孔壁法向刚度和嵌岩桩承载性状的影响还很少受到关注。本文提出的定性分析和讨论为更大尺度上控制桩-岩界面行为的机制提供了洞察力。
Nondestructive imaging techniques enable the study of failure mechanisms within physical models for a wide range of geotechnical problems. This paper presented an innovative experiment that utilized micro X-ray computed tomography (CT) and an in-house experimental apparatus to study the bearing mechanisms of model piles embedded in synthetic soft sandstone rock with regular triangular asperities subjected to compressive loading. X-ray CT image analyses of the model pile-load tests revealed four stages of sliding and shearing between the rock asperities and piles and the interaction mechanisms in each stage were interpreted via schematic representations. Moreover, the compression zone distribution below the model pile tip was consistent with a spherical failure pattern, which is based on the spherical cavity expansion theory. Intuitively, this study supports the applicability of the spherical cavity expansion theory for calculating the end-bearing capacity of piles socketed in soft rock. Additionally, during sliding and initial local shearing, the deformation of the surrounding rock was dominated by the cylindrical cavity expansion, which generated radial cracks inside the rock. The cylindrical cavity expansion theory and Hoek–Brown failure criterion were used to discuss the stress paths of rock of the bore wall and crack formation in the surrounding rock. To date, the effects of these radial cracks on normal stiffness of the bore wall and the bearing behaviour of rock-socketed piles have received little attention. The qualitative analyses and discussion presented in this paper provide insights into the mechanisms governing pile–rock interfacial behaviour at larger scales.
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影响因子：
5.8
作者：
X. Xu;B. Lehane
通讯作者：
X. Xu;B. Lehane
DOI：
--
发表时间：
2015
期刊：
--
影响因子：
--
作者：
M. Silvaa;Gaël COMBEa
通讯作者：
M. Silvaa;Gaël COMBEa
DOI：
--
发表时间：
1975-07
期刊：
--
影响因子：
--
作者：
F. Baguelin;M. Bustamante;P. Frank;J. Jézéquel
通讯作者：
F. Baguelin;M. Bustamante;P. Frank;J. Jézéquel
具有类似三角形粗糙度的混凝土-岩石界面钻孔桩中的荷载传递
DOI：
10.1016/j.ijrmms.2019.06.003
发表时间：
2019-08
影响因子：
7.2
作者：
Heng Zhao;Shuai Zhou;Minghua Zhao
通讯作者：
Minghua Zhao
影响因子：
3.7
作者：
H. Hirayama
通讯作者：
H. Hirayama