基于压电振动效应的振动波测量土体抗剪强度的装置研制

Development of A Device for Measuring Shear Strength of Vibrating Wave Based on Piezoelectric Vibration

土壤抗剪强度是表征土体力学性质的一个重要指标,直接反映了土体在外力作用下发生剪切变形的难易程度。目前对于土壤抗剪强度的检测主要以人工现场采样、实验室仪器分析为主,但这些方法都无法实现现场长期监测,因此存在操作复杂,采样误差大,不能及时反映土壤抗剪强度变化等缺点。本文提出一种基于剪切波速的土体抗剪强度测量装置,如果能够实现野外实时测量土的剪切波波速,则可以获取相应的抗剪强度,实现野外长期现场测量的目的。该装置由压电陶瓷、夹持块、单片机硬件电路等结构组成。取杭州地区的软粘土为研究对象,通过将实验所得数据与实测数据进行分析对比,误差在可接受范围之内,证明了该装置的可行性。

Soil shear strength is an important indicator of the mechanical properties of soil, which directly reflects the difficulty of soil’s shear deformation under external force. At present, the detection of soil shear strength is mainly based on manual site sampling and laboratory instrument analysis. However, these methods can not achieve long-term monitoring at the site. Therefore, there are some shortcomings such as complicated operation and large sampling error, which can not reflect the change of soil shear strength. In this paper, a shear strength measurement device based on shear wave velocity is proposed. If the shear wave velocity of soil can be measured in real time, the corresponding shear strength can be obtained and long-term monitoring at the site can be achieved. The device consists of piezoelectric ceramics, clamping block, single-chip hardware circuit and other structures.We taked the soft clay in Hangzhou as the object of study, and compared the experimental data and measured data. to prove the feasibility of the device. We found that the error is within the acceptable range, so the device is feasible.