岩土振动信号分布式光纤监测的离散元建模研究  

Research on Discrete Element Modeling of Distributed Optical Fiber Monitoring of Geotechnical Vibration Signals

作　　者：王艺澄 闵寅通 刘春[1,2] 李万翀 WANG Yicheng;MIN Yintong;LIU Chun;LI Wanchong(School of Earth Sciences and Engineering,Nanjing University,Nanjing 210023,China;High-Tech Research Institute(Suzhou)of Nanjing University,Suzhou 215123,China)

机构地区：[1]南京大学地球科学与工程学院,江苏南京210023 [2]南京大学(苏州)高新技术研究院,江苏苏州215123

出　　处：《防灾减灾工程学报》2025年第2期307-316,共10页Journal of Disaster Prevention and Mitigation Engineering

基　　金：省级大学生创新创业训练计划支持项目(202410284190Y)、国家自然基金项目(4222707、42477211)资助。

摘　　要：分布式光纤传感(DAS)可获取实时的工程事件振动信号,识别这些信号的特征有利于预警和规避工程灾变风险。为系统地探究不同条件下的DAS信号特征,基于高性能离散元软件MatDEM,建立了岩土体振动信号DAS监测模型,采用弹性Clump模型构建光纤结构体并实时记录相对应变数据,并结合外场重锤下落试验的DAS振动信号数据,从信号的时域特征、频域特征以及信号在振源参数影响下的变化规律三个方面验证了模型的合理性和有效性。研究结果表明,模拟和试验的信号特征具有一致性:信号波形都呈现出单个峰值并快速衰减的特征;信号频率集中,并随着频率增加,振幅逐渐降低;随着重锤下落高度、质量的增加,信号的振幅提高,相应的信噪比增强。模型可用于振动特性机理研究和振动信号大数据生成,有利于进一步的DAS信号解译和人工智能识别。Distributed acoustic sensing(DAS)can obtain real-time vibration signals from engineering events,and identifying these signal characteristics facilitates early warning and prevention of engineering disasters.To systematically investigate the characteristics of DAS signals under different conditions,a DAS monitoring model for geotechnical vibration signals was established using the high-performance discrete element method(DEM)software,MatDEM.The elastic Clump model was em-ployed to construct optical fiber structures and record relative strain data in real time.By integrating DAS vibration signal data from field drop-weight impact tests,the model's validity and effectiveness were verified from three aspects:time-domain characteristics,frequency-domain characteristics,and variation patterns of signals influenced by vibration source parameters.The results demonstrated consistency between simulated and experimental signal characteristics.The signal waveforms consistently exhibited a single-peak pattern with rapid attenuation.Signal frequencies were concentrated,and amplitudes gradually decreased with increasing frequency.As the drop height and mass of the impact weight increased,the signal amplitudes and corresponding signal-to-noise ratios increased.This model can be used for research on vibration mechanism characteristics and for generating large-scale datasets of vibration signals,thereby facilitating further interpretation of DAS signals and their recognition through artificial intelligence technology.

关 键 词：离散元法 数值模拟 分布式监测 振动信号 时域分析 频域分析 

分 类 号：P642[天文地球—工程地质学]