基于压电智能骨料的3D打印断续节理围岩内部损伤监测  

Monitoring of Internal Damage of 3D Printed Surrounding Rock With Intermittent Joints Based on Piezoelectric Intelligent Aggregates

作　　者：马国伟[1,2] 黄晨 张俊飞 MA Guowei;HUANG Chen;ZHANG Junfei(College of Architecture and Civil Engineering,Beijing University of Technology,Beijing 100124,China;School of Civil and Transportation Engineering,Hebei University of Technology,Tianjin 300401,China)

机构地区：[1]北京工业大学建筑工程学院,北京100124 [2]河北工业大学土木与交通学院,天津300401

出　　处：《北京工业大学学报》2023年第8期862-873,共12页Journal of Beijing University of Technology

基　　金：国家自然科学基金资助项目(51627812)。

摘　　要：3D打印模型试验是研究复杂地质结构损伤机制的有效手段,3D打印逐层堆积过程中定位压电骨料可有效提高埋设精确度和模型内部损伤监测精度。该文采用3D打印增减材技术制备内部埋设压电骨料的断续节理围岩模型,基于压电骨料与数字图像相关技术(digital image correlation,DIC)监测围岩模型在单轴加载下的破坏过程,研究节理连通率对围岩模型破坏机制的影响规律,验证压电骨料定位围岩模型起裂位置和监测内部裂隙损伤扩展的可行性。结果表明:1)随着节理连通率的增大,围岩模型荷载-位移曲线的峰值强度降低、延性增强,由单峰曲线变为多峰曲线;2)断续节理围岩模型的起裂位置多在临近洞口的节理尖端或顶板和底板的中部,裂纹扩展方向大多沿着节理尖端方向,表现为块体分离破坏;3)预制节理连通率增大会导致同路径的监测信号能量衰减,连通率与信号能量之间表现出抛物线相关性;4)压电骨料监测方法相比于DIC监测等宏观监测方法可以更早一步发现模型内部损伤,并能确定内部损伤的位置。3D concrete printing test is an effective means to study the damage mechanism of complex geological structures.During the printing process,piezoelectric aggregates can be accurately put in the designed palaces in the printed model,which improves the accuracy of damage identification.In this paper,the 3D printing technology was used to prepare the surrounding rock model with intermittent joints.The damage process of the model under uniaxial loading was monitored based on piezoelectric aggregates and digital image correlation(DIC).The influence of intermittent joint connectivity on the failure mechanism of the surrounding rock model was studied,and the feasibility of monitoring the crack-initiation position and crack propagation with piezoelectric aggregates was verified.Results show that the ductility of the load-displacement curve increases with the increase of the joint connectivity ratio,changing from a single-peak curve to a multi-peak curve.The crack-initiation position of the surrounding rock model is mostly located at the joint tip or the middle of the roof and floor.The crack propagation direction is mostly along the joint tip,and the failure mode is block-separation failure.The increase of the connectivity ratio of the prefabricated joints in the surrounding rock leads to the attenuation of the monitoring signal energy in the same path,and there is a parabolic correlation between the connectivity ratio and the signal energy.Compared with macroscopic observation methods such as DIC,the piezoelectric aggregate monitoring method can detect the damage of the model structure earlier and determine the location of the damage.

关 键 词：压电骨料 小波能量分析 3D打印 断续节理 模型试验 内部损伤 

分 类 号：TU455[建筑科学—岩土工程]