压电波动法监测土壤含水率的可行性研究

基础工程施工的安全性常以基坑稳定性为前提，而土壤的含水率是边坡稳定性的关键因素。但是，土体内部含水率的观测困难，很难实时了解土体内部水分的变化情况。目前对土壤含水率进行监测的方法较少，故而迫切需要一种对土体结构含水率进行实时监测的方法。该文通过制作简易土箱，利用压电智能骨料并结合压电波动法对土箱内土壤进行含水率监测，获得了不同含水率下的压电信号及小波包能量。基于小波包分析方法发现，压电信号幅值及对应的小波包能量指数与土壤含水率呈正相关关系，且土壤含水率越大，小波包能量指数的上升速率越慢，并在其含水率接近饱和时基本不再变化，验证了该土壤含水率监测方法具有良好可行性。

Feasibility Study on Detection of Moisture Content of Soil Based on Piezoelectric Wave Method

The safety of foundation engineering construction is often based on the stability of the foundation pit, and the moisture content of the soil is the key factor of slope stability. However, it is very difficult to observe the internal moisture content of the soil, so it is difficult to understand the change of soil moisture in real time. At present, there are few methods to monitor soil moisture content. Therefore, there is an urgent need for a method of real time monitoring the moisture content of the soil structure. In this paper, by making a simple soil box, using piezoelectric intelligent aggregate and combining with the piezoelectric wave method, the soil moisture content in the soil box is monitored, and the piezoelectric signal and wavelet packet energy under different moisture content are obtained. Based on the wavelet packet analysis method, it is found that the amplitude of the piezoelectric signal and the corresponding wavelet packet energy index are positively correlated with the soil moisture content; and the higher the soil moisture content, the slower the rising rate of wavelet packet energy index, and it basically does not change when the soil moisture is close to saturation.It is verified that the proposed method has good feasibility.