低温环境下基于压电陶瓷监测技术的土体强度试验研究  

Experimental study on soil strength based on piezoelectric ceramic monitoring technology in low-temperature environment

作　　者：辜世旺 全晓娟[1] 龚禹为 钟官峰 汪波[1] GU Shiwang;QUAN Xiaojuan;GONG Yuwei;ZHONG Guanfeng;WANG Bo(State Key Laboratory of Intelligent Geotechnics and Tunneling,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学极端环境岩土和隧道工程智能建养全国重点实验室,四川成都610031

出　　处：《冰川冻土》2024年第6期1860-1870,共11页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金联合基金项目(U2034205)资助。

摘　　要：冻土强度对评估冻土区构筑物的稳定与安全具有重要作用。然而受制于冻土复杂的四相介质体系,目前尚无成熟的手段来实时监测土体力学性能。以东北地区某工程现场粉砂土为对象,基于压电陶瓷测试技术,结合低温三轴试验,对不同负温状态下土体的力学性态进行定量研究。结果表明:随着温度的降低,土体的破坏强度、弹性模量、黏聚力均呈现出先快后慢的增长趋势。同时,传感器接收到的压电信号时域图像呈延伸和扩展态势,且主要信号频率范围逐渐向高频方向移动,压电信号能量对土体强度变化有很强敏感性。基于小波包分析得到的分解信号能量,建立粉砂土强度强化指标,该指标能很好地反映负温与土体强度的关系。研究结果可为压电陶瓷测试技术的工程应用提供参考。The strength of frozen soil plays an important role in evaluating the stability and safety of structures in frozen soil areas.However,due to the complex four-phase medium system of frozen soil,there are no mature means to monitor the mechanical properties of soil in real time.Based on the piezoelectric ceramic test technology and the low-temperature triaxial test,the mechanical properties of the soil under different negative temperature conditions are quantitatively studied by taking the silty sand in a project site in northeast China as the object.The results show that with the decrease of temperature,the failure strength,elastic modulus and cohesion of soil show a trend of rapid growth first and then slow growth.At the same time,the time domain image of the piezoelectric signal received by the sensor is extended and expanded,and the main signal frequency range gradually moves to the high frequency direction.The energy of the piezoelectric signal is very sensitive to the change of soil strength.Based on the decomposition signal energy obtained by wavelet packet analysis,the strength strengthening index of silty sand is established,which can well reflect the relationship between negative temperature and soil strength.The research results can provide reference for the engineering application of piezoelectric ceramic testing technology.

关 键 词：冻结三轴试验 土体强度 压电陶瓷 小波包分析 

分 类 号：P642.14[天文地球—工程地质学]